WO2018181202A1 - Semiconductor light-emitting element and method for manufacturing semiconductor light-emitting element - Google Patents
Semiconductor light-emitting element and method for manufacturing semiconductor light-emitting element Download PDFInfo
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- WO2018181202A1 WO2018181202A1 PCT/JP2018/012188 JP2018012188W WO2018181202A1 WO 2018181202 A1 WO2018181202 A1 WO 2018181202A1 JP 2018012188 W JP2018012188 W JP 2018012188W WO 2018181202 A1 WO2018181202 A1 WO 2018181202A1
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- H01S5/00—Semiconductor lasers
- H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
- H01S5/12—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers
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- H01S5/00—Semiconductor lasers
- H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
- H01S5/18—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities
- H01S5/185—Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities having only horizontal cavities, e.g. horizontal cavity surface-emitting lasers [HCSEL]
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- H01S5/00—Semiconductor lasers
- H01S5/04—Processes or apparatus for excitation, e.g. pumping, e.g. by electron beams
- H01S5/042—Electrical excitation ; Circuits therefor
- H01S5/0425—Electrodes, e.g. characterised by the structure
- H01S5/04254—Electrodes, e.g. characterised by the structure characterised by the shape
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- H01S5/00—Semiconductor lasers
- H01S5/04—Processes or apparatus for excitation, e.g. pumping, e.g. by electron beams
- H01S5/042—Electrical excitation ; Circuits therefor
- H01S5/0425—Electrodes, e.g. characterised by the structure
- H01S5/04256—Electrodes, e.g. characterised by the structure characterised by the configuration
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- H01S5/00—Semiconductor lasers
- H01S5/40—Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30
- H01S5/42—Arrays of surface emitting lasers
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- H01S2301/00—Functional characteristics
- H01S2301/17—Semiconductor lasers comprising special layers
- H01S2301/176—Specific passivation layers on surfaces other than the emission facet
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- H01S5/00—Semiconductor lasers
- H01S5/02—Structural details or components not essential to laser action
- H01S5/026—Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers
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- H01S5/00—Semiconductor lasers
- H01S5/02—Structural details or components not essential to laser action
- H01S5/028—Coatings ; Treatment of the laser facets, e.g. etching, passivation layers or reflecting layers
- H01S5/0287—Facet reflectivity
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- H01S5/00—Semiconductor lasers
- H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
- H01S5/12—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers
- H01S5/1203—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers over only a part of the length of the active region
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- H01S5/00—Semiconductor lasers
- H01S5/20—Structure or shape of the semiconductor body to guide the optical wave ; Confining structures perpendicular to the optical axis, e.g. index or gain guiding, stripe geometry, broad area lasers, gain tailoring, transverse or lateral reflectors, special cladding structures, MQW barrier reflection layers
- H01S5/2054—Methods of obtaining the confinement
- H01S5/2059—Methods of obtaining the confinement by means of particular conductivity zones, e.g. obtained by particle bombardment or diffusion
- H01S5/2063—Methods of obtaining the confinement by means of particular conductivity zones, e.g. obtained by particle bombardment or diffusion obtained by particle bombardment
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/30—Structure or shape of the active region; Materials used for the active region
- H01S5/34—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
- H01S5/343—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers in AIIIBV compounds, e.g. AlGaAs-laser, InP-based laser
- H01S5/34313—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers in AIIIBV compounds, e.g. AlGaAs-laser, InP-based laser with a well layer having only As as V-compound, e.g. AlGaAs, InGaAs
Definitions
- the present invention relates to a semiconductor light emitting device and a method for manufacturing the same.
- the semiconductor light-emitting element described in Patent Document 1 includes an active layer and a phase modulation layer optically coupled to the active layer.
- the phase modulation layer has a base layer and a plurality of different refractive index regions arranged in the base layer.
- the semiconductor light emitting element described in Patent Document 1 emits light of a beam pattern (beam projection pattern) corresponding to the arrangement pattern of a plurality of different refractive index regions. That is, the arrangement pattern of the plurality of different refractive index regions is set according to the target beam pattern.
- Patent Document 1 also describes an application example of such a semiconductor light emitting element.
- a plurality of semiconductor light emitting elements each having a different direction of the emitted laser beam are arranged one-dimensionally or two-dimensionally on a support substrate.
- the said application example is comprised so that a laser beam may be scanned with respect to a target object by lighting the arranged several semiconductor light-emitting element sequentially.
- the application example described above is applied to distance measurement to an object, laser processing of the object, and the like by scanning the object with a laser beam.
- the present invention has been made in view of such problems, and does not require a step of disposing a plurality of semiconductor light emitting elements on a support substrate, and makes it easy to irradiate a target beam projection area with light of a target beam projection pattern. It is another object of the present invention to provide a semiconductor light emitting device and a method for manufacturing the same that are realized with high accuracy.
- the semiconductor light-emitting device is a single semiconductor light-emitting device having a plurality of light-emitting portions in which crosstalk between adjacent light-emitting portions is reduced, and a first surface and a first surface facing the first surface.
- a semiconductor light emitting device having two surfaces, wherein one of the first surface and the second surface functions as a light emitting surface that outputs light, and the other functions as a support surface (including a reflective surface), and an active layer
- a phase modulation layer including a plurality of phase modulation regions, a first cladding layer, a second cladding layer, a first surface side electrode, a plurality of second surface side electrodes, and a common substrate layer.
- the active layer is located between the first surface and the second surface.
- the plurality of phase modulation layers included in the phase modulation layer are optically coupled to the active layer.
- Each of the plurality of phase modulation areas is arranged so as to reduce the occurrence of crosstalk between adjacent phase modulation areas, and each constitutes a part of an independent light emitting unit.
- Each of the plurality of phase modulation regions includes a basic region having a first refractive index, and a plurality of different refractive index regions each provided in the basic region and having a second refractive index different from the first refractive index.
- the first cladding layer is located on the side where the first surface is disposed with respect to the multilayer structure including at least the active layer and the phase modulation layer.
- the second cladding layer is disposed on the side where the second surface is located with respect to the laminated structure.
- the first surface side electrode is disposed on the side where the first surface is located with respect to the first cladding layer.
- the plurality of second surface side electrodes respectively correspond to the plurality of phase modulation regions, and are disposed on the side where the second surface is located with respect to the second cladding layer.
- the plurality of second surface side electrodes are respectively disposed in a plurality of regions overlapping with the plurality of phase modulation regions when viewed along the stacking direction of the stacked structure.
- the common substrate layer is disposed between the first cladding layer and the first surface side electrode and has a continuous surface that holds a plurality of phase modulation regions.
- the plurality of different refractive index regions in each of the plurality of phase modulation regions are arranged in accordance with an arrangement pattern in which each center of gravity is located at a position that is shifted by a predetermined distance from each lattice point in a virtual square lattice in the basic region. Arranged in the base area.
- the arrangement pattern in each of the plurality of phase modulation regions (arrangement pattern of the plurality of different refractive index regions) is supplied with a drive current from the second surface side electrode arranged on the support surface side and corresponding to the phase modulation region.
- the beam projection pattern of the light output from the light exit surface and the beam projection area that is the projection range of the beam projection pattern are determined to coincide with the target beam projection pattern and the target beam projection area.
- the method for manufacturing a semiconductor light emitting device manufactures a semiconductor light emitting device having the above-described structure.
- the manufacturing method includes a first step of forming a common substrate layer, a second step of forming an element body on the common substrate layer, and a third step of forming an isolation region in the element body.
- the element main body formed on the common substrate layer has a third surface and a fourth surface facing the third surface and facing the common substrate layer.
- the element body includes at least an active layer, a phase modulation layer, a first cladding layer, and a second cladding layer disposed between the third surface and the fourth surface.
- the basic region in the phase modulation layer is arranged in a state where a plurality of portions (each of which includes a plurality of different refractive index regions) to be a plurality of phase modulation regions are separated from each other by a predetermined distance. Composed of a single layer.
- the separation region formed in the element body electrically separates at least a plurality of portions to be a plurality of phase modulation regions.
- the isolation region is formed from the third surface toward the fourth surface until reaching the common substrate layer.
- the present invention there is no need for a step of disposing a plurality of semiconductor light emitting elements on a support substrate, and the semiconductor light emitting element in which irradiation of light of a target beam projection pattern to a target beam projection region is realized easily and with high accuracy.
- a manufacturing method thereof can be provided.
- FIG. 3 is a cross-sectional view taken along line III-III in FIGS.
- FIGS. 1-10 These are the figures for demonstrating the relationship between the target beam projection pattern (light image) of the light output from a semiconductor light-emitting device, and the rotation angle distribution in a phase modulation layer.
- FIG. 10 These are the figures which show an example of a target beam projection pattern in the semiconductor light-emitting device which concerns on 1st Embodiment, and phase distribution among the complex amplitude distribution obtained by carrying out the inverse Fourier transform of the original pattern corresponding to it.
- FIG. 1 show the structure of a light-emitting device provided with the semiconductor light-emitting element concerning 1st Embodiment.
- FIG. 1st Embodiment These are the figures which looked at the semiconductor light-emitting device concerning 2nd Embodiment from the 1st surface side.
- FIG. 11 is a sectional view taken along line XX in FIGS. 9 and 10.
- FIG. 12 shows an example of a target beam projection pattern different from that in FIG. 12 in the semiconductor light emitting device according to the second and third embodiments, and a phase distribution among complex amplitude distributions obtained by inverse Fourier transform of the corresponding original pattern.
- FIG. 12 shows an example of a target beam projection pattern different from that in FIG. 12 in the semiconductor light emitting device according to the second and third embodiments, and a phase distribution among complex amplitude distributions obtained by inverse Fourier transform of the corresponding original pattern.
- FIGS. 15 and 16 It is a block diagram which shows the structure of a light-emitting device provided with the semiconductor light-emitting device concerning 3rd Embodiment. These are the figures which looked at the semiconductor light-emitting device concerning a 4th embodiment from the 1st surface side.
- FIG. 21 is a cross-sectional view taken along line XX-XX in FIGS. 19 and 20.
- FIG. 5 is a diagram showing an example (rotation method) of the XY in-plane shape of the different refractive index region that does not have 180 ° rotational symmetry. These are figures which show the 1st modification of the phase modulation area
- a different refractive index region (displacement different refractive index when a lattice point different refractive index region is provided in addition to the different refractive index region (displacement different refractive index region))
- FIG. 1 Shows an example of a combination of a different refractive index region (displacement different refractive index region) and a lattice point refractive index region in the case of providing a different refractive index region (displacement different refractive index region) in addition to a different refractive index region (displacement different refractive index region).
- FIG. These are figures which show the modification (rotation system) in the case of providing a lattice point different refractive index area
- FIG. 29 is a plan view showing an example in which a refractive index substantially periodic structure is applied only in a specific region of the phase modulation layer as a first modification of the phase modulation layer in FIG. 28.
- FIG. 33 is a phase distribution corresponding to the beam projection pattern shown in FIG. 32A and a partially enlarged view thereof.
- the inclination angle of the straight line L with respect to the X axis and the Y axis is 45 °.
- a rotation method for rotating the different refractive index regions around the lattice points and traveling waves AU, AD, AR, and AL as a method for determining the arrangement pattern of the different refractive index regions.
- FIG. 29 is a diagram showing a second modification of the phase modulation layer in FIG. 28. These are figures for demonstrating the coordinate transformation from spherical coordinates (d1, ⁇ tilt , ⁇ rot ) to coordinates (x, y, z) in the XYZ orthogonal coordinate system.
- the semiconductor light-emitting device is a single semiconductor light-emitting device having a plurality of light-emitting portions in which crosstalk between adjacent light-emitting portions is reduced, as one aspect thereof,
- a semiconductor having a second surface facing the first surface, wherein one of the first surface and the second surface functions as a light emitting surface that outputs light, and the other functions as a support surface (including a reflective surface)
- a common substrate layer is located between the first surface and the second surface.
- the plurality of phase modulation layers included in the phase modulation layer are optically coupled to the active layer.
- Each of the plurality of phase modulation areas is arranged so as to reduce the occurrence of crosstalk between adjacent phase modulation areas, and each constitutes a part of an independent light emitting unit.
- Each of the plurality of phase modulation regions includes a basic region having a first refractive index, and a plurality of different refractive index regions each provided in the basic region and having a second refractive index different from the first refractive index.
- the first cladding layer is located on the side where the first surface is disposed with respect to the multilayer structure including at least the active layer and the phase modulation layer.
- the second cladding layer is disposed on the side where the second surface is located with respect to the laminated structure.
- the first surface side electrode is disposed on the side where the first surface is located with respect to the first cladding layer.
- the plurality of second surface side electrodes respectively correspond to the plurality of phase modulation regions, and are disposed on the side where the second surface is located with respect to the second cladding layer.
- the plurality of second surface side electrodes are respectively disposed in a plurality of regions overlapping with the plurality of phase modulation regions when viewed along the stacking direction of the stacked structure.
- the common substrate layer is disposed between the first cladding layer and the first surface side electrode and has a continuous surface that holds a plurality of phase modulation regions.
- each of the plurality of phase modulation regions is output from the light emitting surface when the driving current is supplied from the corresponding second surface side electrode among the plurality of second surface side electrodes.
- the light beam projection pattern and the beam projection area that is the projection range of the beam projection pattern are arranged at predetermined positions in the basic area according to the arrangement pattern for matching the target beam projection pattern and the target beam projection area, respectively. .
- a Z axis that coincides with the normal direction of the light exit surface and an X axis and a Y axis that coincide with one surface of the phase modulation layer including a plurality of different refractive index regions are orthogonal to each other.
- M1 (an integer of 1 or more) ⁇ N1 (an integer of 1 or more) unit constituent regions each having a square shape on the XY plane A virtual square lattice constituted by R is set.
- the arrangement pattern is a unit on the XY plane specified by a coordinate component x (an integer between 1 and M1) in the X-axis direction and a coordinate component y (an integer between 1 and N1) in the Y-axis direction.
- the lattice point O (x, y) where the centroid G1 of the different refractive index region located in the unit configuration region R (x, y) is the center of the unit configuration region R (x, y). It is defined that the vector from the grid point O (x, y) to the centroid G1 is directed in a specific direction, and is separated from the y) by a distance r.
- the semiconductor light-emitting device manufacturing method manufactures a semiconductor light-emitting device having the above-described structure as one aspect thereof.
- the manufacturing method includes a first step of forming a common substrate layer, a second step of forming an element body on the common substrate layer, and a third step of forming an isolation region in the element body.
- the element main body formed on the common substrate layer has a third surface and a fourth surface facing the third surface and facing the common substrate layer.
- the element body includes at least an active layer, a phase modulation layer, a first cladding layer, and a second cladding layer disposed between the third surface and the fourth surface.
- the basic region in the phase modulation layer is arranged in a state where a plurality of portions (each of which includes a plurality of different refractive index regions) to be a plurality of phase modulation regions are separated from each other by a predetermined distance. Composed of a single layer.
- the separation region formed in the element body electrically separates at least a plurality of portions to be a plurality of phase modulation regions. The separation region is formed from the third surface toward the fourth surface until reaching the common substrate layer.
- the arrangement pattern in each of the plurality of phase modulation regions (the arrangement pattern of the plurality of different refractive index regions) is supplied with a drive current from the second surface side electrode corresponding to the phase modulation region.
- the beam projection pattern of the light output from the light emission surface (first surface or second surface) and the beam projection area that is the projection range of the beam projection pattern coincide with the target beam projection pattern and the target beam projection area It is stipulated to be. Therefore, the arrangement pattern set in each of the plurality of phase modulation regions determines the beam projection region and the beam projection pattern of light output from the light emitting surface of the semiconductor light emitting element.
- one semiconductor light emitting element includes a phase modulation layer having a plurality of phase modulation areas for determining a light beam projection area and a beam projection pattern.
- the semiconductor light emitting element electrically separates each of the plurality of phase modulation regions and is viewed from a direction along the Z axis (hereinafter referred to as “Z axis direction”).
- Z axis direction A separation region that electrically separates a plurality of corresponding regions in each of the active layer, the first cladding layer, and the second cladding layer, which sometimes overlaps the plurality of phase modulation regions, may be further provided.
- the separation region optically separates a plurality of corresponding regions in each of the active layer, the phase modulation layer, the first cladding layer, and the second cladding layer together with the plurality of phase modulation regions. May be.
- the adjacent phase modulation regions are electrically separated by the separation region, so that occurrence of crosstalk between the adjacent phase modulation regions is suppressed. Further, since the adjacent phase modulation areas are optically separated by the separation areas, the occurrence of crosstalk between the adjacent phase modulation areas is further suppressed. As a result, irradiation of light of a desired beam projection pattern (target beam projection pattern) to a desired beam projection area (target beam projection area) is realized with higher accuracy.
- the separation region reaches the common substrate layer from the second surface toward the common substrate layer surface in a region between adjacent phase modulation regions among the plurality of phase modulation regions. It grows until you do.
- the distance (shortest distance) between the tip of the separation region and the first surface side electrode is not more than half the thickness of the common substrate layer along the Z-axis direction.
- the distance between the tip of the separation region and the first surface side electrode is preferably 70 ⁇ m or less. In this case, the occurrence of crosstalk between adjacent phase modulation regions is sufficiently suppressed.
- the separation region may be a semiconductor layer modified by an electric field resulting from high-intensity light irradiation.
- a semiconductor light emitting device in which adjacent phase modulation regions are electrically separated and generation of crosstalk between adjacent phase modulation regions is sufficiently suppressed can be efficiently manufactured.
- the isolation region may be any of a semiconductor layer insulated by impurity diffusion or ion implantation and an air gap (slit) formed by dry etching or wet etching. In this case, a semiconductor light emitting device in which adjacent phase modulation regions are electrically and optically separated, and occurrence of crosstalk between adjacent phase modulation regions is sufficiently suppressed can be efficiently manufactured. .
- the arrangement pattern in each of the phase modulation regions is determined so that the beam projection patterns are equal even when a drive current is supplied from any of the plurality of second surface side electrodes. May be.
- an application similar to the application example of the semiconductor light emitting device disclosed in Patent Document 1 application example in which the laser beam is scanned with respect to the object
- various other applications are also possible. It becomes possible.
- an application different from the application example shown in Patent Document 1 it is applied to various types of illumination in which the same pattern light is continuously or intermittently applied to one place, and the same pattern pulse light is continuously applied to one place.
- the phase modulation layer optically coupled to the active layer is embedded in the basic layer and the refractive index different from the refractive index of the basic layer.
- a plurality of different refractive index regions each having a refractive index.
- the centroid G1 of the corresponding different refractive index region is arranged away from the lattice point O (x, y). Furthermore, the direction of the vector from the lattice point O to the center of gravity G1 is individually set for each unit configuration region R.
- the phase of the beam changes depending on the direction of the vector from the lattice point O to the centroid G1 of the corresponding refractive index region, that is, the angular position around the lattice point of the centroid G1 of the different refractive index region.
- the phase of the beam output from each of the different refractive index regions can be controlled only by changing the position of the center of gravity of the different refractive index region, and the beam projection formed as a whole
- the pattern (a group of beams forming an optical image) can be controlled to a desired shape.
- the lattice point in the virtual square lattice may be located outside the different refractive index region, or the lattice point may be located inside the different refractive index region.
- the lattice constant (substantially equivalent to the lattice spacing) of a virtual square lattice is a
- the different refractive index located in the unit constituent region R (x, y) The distance r between the center of gravity G1 of the region and the lattice point O (x, y) preferably satisfies 0 ⁇ r ⁇ 0.3a.
- an original image serving as a beam projection pattern of light emitted from a semiconductor light emitting element corresponding to each of a plurality of phase modulation regions, for example, a spot, three or more points It preferably includes at least one of a spot group consisting of: a straight line, a cross, a line drawing, a lattice pattern, a striped pattern, a figure, a photograph, computer graphics, and characters.
- the coordinates (x, y, z) in the XYZ orthogonal coordinate system are as shown in FIG. Spherical coordinates (d1, ⁇ tilt , ⁇ rot ) defined by the length d1 of the lens , the tilt angle ⁇ tilt from the Z axis, and the rotation angle ⁇ rot from the X axis specified on the XY plane
- FIG. 1 Spherical coordinates (d1, ⁇ tilt , ⁇ rot ) defined by the length d1 of the lens , the tilt angle ⁇ tilt from the Z axis, and the rotation angle ⁇ rot from the X axis specified on the XY plane
- z represents a design optical image on a predetermined plane (target beam projection region) set in the XYZ orthogonal coordinate system which is a real space.
- the angle theta tilt and theta rot has the following formula ( 4) the normalized wave number defined by 4) and corresponding to the coordinate value k x on the Kx axis corresponding to the X axis, and the normalized wave number defined by the following equation (5) corresponding to the Y axis and Kx shall be converted into coordinate values k y on Ky axis perpendicular to the axis.
- the normalized wave number means a wave number normalized with 1.0 as the wave number corresponding to the lattice spacing of a virtual square lattice.
- FR k x, k y
- X-axis coordinate component x an integer of 1 to M1
- Y-axis coordinate component y an integer of 1 to N1
- the complex amplitude F (x, y) obtained by performing the two-dimensional inverse Fourier transform on the unit configuration region R (x, y) on the plane is given by the following formula (6), where j is an imaginary unit.
- the complex amplitude F (x, y) is defined by the following equation (7), where the amplitude term is A (x, y) and the phase term is P (x, y). Further, as a fourth precondition, the unit configuration region R (x, y) is parallel to the X axis and the Y axis, and is a lattice point O (x, y) that is the center of the unit configuration region R (x, y). ) In the orthogonal s axis and t axis.
- the corresponding different refractive index regions are arranged so as to satisfy the following relationship.
- the distance r between the center (lattice point) of each unit constituting region constituting the virtual square lattice and the centroid G1 of the corresponding different refractive index region is preferably a constant value over the entire phase modulation layer (note that it is not excluded that the distance r is partially different).
- the phase distribution in the entire phase modulation layer (the distribution of the phase term P (x, y) in the complex amplitude F (x, y) assigned to the unit configuration region R (x, y)) is 0 to 2 ⁇ (rad ),
- the center of gravity of the different refractive index region coincides with the lattice point of the unit constituent region R in the square lattice. Therefore, the two-dimensional distributed Bragg diffraction effect in the above phase modulation layer is close to the two-dimensional distributed Bragg diffraction effect when the different refractive index region is arranged on each lattice point of the square lattice. Can be easily formed, and a reduction in threshold current for oscillation can be expected.
- the unit configuration region R (x, y) passes through the lattice point O (x, y) under the first to fourth preconditions.
- the center of gravity G1 of the different refractive index region corresponding to the straight line inclined from the axis is arranged.
- the corresponding different refractive index regions are arranged in the unit configuration region R (x, y) so as to satisfy the following relationship. Even when the arrangement pattern of the different refractive index regions in the phase modulation layer is determined by the on-axis shift method, the same effect as the above rotation method is obtained.
- all of the plurality of different refractive index regions have a shape defined on the XY plane, XY It is preferable that at least one of the area defined on the plane and the distance r defined on the XY plane coincide with each other.
- the above-mentioned “shape defined on the XY plane” includes a combined shape of a plurality of elements constituting one different refractive index region (see FIGS. 25 (h) to 25 (k)). . According to this, generation of noise light and zero-order light that becomes noise in the beam projection region can be suppressed.
- the zero-order light is light output in parallel with the Z-axis direction, and means light that is not phase-modulated in the phase modulation layer.
- the shape of the plurality of different refractive index regions on the XY plane is a perfect circle, square, regular hexagon, regular octagon, regular hexagon, regular triangle, right isosceles triangle , A rectangle, an ellipse, a shape in which two circles or a portion of an ellipse overlap, an oval shape, a teardrop shape, an isosceles triangle, an arrow shape, a trapezoid, a pentagon, and a shape in which two rectangles overlap It is preferable.
- the oval shape has a dimension in the short axis direction near one end portion along the long axis thereof, which is near the other end portion. It is a shape obtained by deforming an ellipse so as to be smaller than the dimension in the minor axis direction.
- the teardrop shape deforms one end of an ellipse along its long axis into a sharp end protruding along the long axis. It is a shape obtained by doing.
- the arrow shape as shown in FIGS. 22E and 38G, one side of the rectangle forms a triangular cutout, and the side opposite to the one side forms a triangular protrusion. It is a shape.
- the shape of the plurality of different refractive index regions on the XY plane is any of a perfect circle, a square, a regular hexagon, a regular octagon, a regular hexagon, a rectangle, and an ellipse, that is, When the shape is mirror-image symmetric (line symmetric), in the phase modulation layer, from the lattice point O of each of the plurality of unit constituting regions R constituting the virtual square lattice, to the centroid G1 of the corresponding different refractive index region. It is possible to set the angle ⁇ formed by the direction in which the heading direction and the s-axis parallel to the X-axis with high accuracy.
- the shape of the plurality of different refractive index regions on the XY plane is a regular triangle, a right isosceles triangle, an isosceles triangle, a shape in which two circles or a part of an ellipse overlap, an egg shape, a teardrop shape, In the case of any one of an arrow shape, a trapezoid, a pentagon, and a shape in which a part of two rectangles overlap each other, that is, when a rotational symmetry of 180 ° is not provided, higher light output can be obtained.
- At least one phase modulation region among the plurality of phase modulation regions surrounds an inner region composed of M1 ⁇ N1 unit configuration regions R and an outer periphery of the inner region. And an outer region provided as described above.
- the outer region has a plurality of peripherals arranged so as to overlap with lattice points in the extended square lattice defined by setting the same lattice structure as the virtual square lattice on the outer periphery of the virtual square lattice. Includes a lattice point refractive index region. In this case, light leakage along the XY plane is suppressed, and the oscillation threshold current can be reduced.
- At least one phase modulation region among the plurality of phase modulation regions includes a plurality of different refractive index regions different from the plurality of different refractive index regions, that is, a plurality of lattice points.
- a different refractive index region may be provided.
- the plurality of different refractive index regions are respectively arranged in M1 ⁇ N1 unit configuration regions R, and are arranged so that the respective centroids G2 coincide with the lattice points O of the corresponding unit configuration regions R.
- the combined shape composed of the different refractive index region and the lattice point different refractive index region does not have a rotational symmetry of 180 ° as a whole. Therefore, higher light output can be obtained.
- each aspect listed in this [Description of Embodiments of the Invention] is applicable to each of all the remaining aspects or to all combinations of these remaining aspects. .
- FIG. 1 is a view of the semiconductor light emitting device 100 according to the first embodiment as viewed from the first surface side.
- 2 is a view of the semiconductor light emitting device 100 as viewed from the second surface side, and
- FIG. 3 is a cross-sectional view taken along line III-III in FIGS.
- the semiconductor light emitting device 100 has a first surface 100a and a second surface 100b, and outputs light from the first surface 100a as a light emitting surface.
- the second surface 100b functions as a support surface.
- the semiconductor light emitting device 100 includes a common substrate layer 101, an active layer 103, a phase modulation layer 104, a first cladding layer 102, a second cladding layer 106, and a pair of second surface side electrodes 108-1, 108-. 2 and the first surface side electrode 110.
- the phase modulation layer 104 has a pair of phase modulation regions 104-1 and 104-2 that are optically coupled to the active layer 103.
- a laminated structure is configured by at least the phase modulation layer 104 including the active layer 103 and the pair of phase modulation regions 104-1 and 104-2.
- the configuration of the laminated structure is the same in the embodiments described later.
- the first cladding layer 102 is located on the first surface 100a side with respect to the stacked structure (including at least the active layer 103 and the phase modulation layer 104).
- the second cladding layer 106 is located on the second surface 100b side with respect to the stacked structure (including at least the active layer 103 and the phase modulation layer 104).
- the second surface side electrodes 108-1 and 108-2 are on the side where the second surface 100b is disposed with respect to the second cladding layer 106, and positions corresponding to the phase modulation regions 104-1 and 104-2, respectively. Is arranged.
- the first surface side electrode 110 is located on the side where the first surface 100 a is disposed with respect to the first cladding layer 102.
- the phase modulation regions 104-1 and 104-2 include basic regions 104-1a and 104-2a having a first refractive index, and a plurality of different refractive index regions having a second refractive index different from the first refractive index, respectively.
- 104-1b and 104-2b The plurality of different refractive index regions 104-1b and 104-2b are located at locations where the respective centroids G1 are shifted by a predetermined distance r from each lattice point in the virtual square lattice in the basic regions 104-1a and 104-2a. They are arranged in the basic areas 104-1a and 104-2a in accordance with the arrangement pattern.
- the arrangement pattern of the plurality of different refractive index regions 104-1b is the second surface side electrode 108-1 corresponding to the phase modulation region 104-1 or 104-2.
- the beam projection pattern expressed by the light output from the first surface 100a when the drive current is supplied from 108-2 and the beam projection area which is the projection range of the beam projection pattern are the target beam projection pattern and the target beam. It is set to match the projection area.
- the projection area may be the same or different.
- the projection pattern may be the same or different.
- beam projection region in this specification refers to a projection range of light output from the first surface or the second surface of the semiconductor light emitting element when a driving current is supplied from one second surface side electrode.
- Beam projection pattern refers to a light projection pattern (light intensity pattern) within the projection range.
- the active layer 103, the phase modulation layer 104, the first cladding layer 102, the second cladding layer 106, and the common substrate layer 101 reach the common substrate layer 101 from the second surface 100b toward the common substrate layer 101.
- a separation region 112 is provided that extends to the end. The separation region 112 overlaps with the phase modulation regions 104-1 and 104-2 when viewed from the Z-axis direction (stacking direction), the active layer 103, the first cladding layer 102, the second cladding layer 106, and the first cladding layer. 102 and the second cladding layer 106 respectively extend from the second surface 100b toward the common substrate layer 101 so as to electrically and optically separate corresponding regions.
- the thickness of the portion of the common substrate layer 101 located below the separation region 112 is: The thickness is less than half of the thickness of the common substrate layer 101, and typically less than 70 ⁇ m. As shown in FIG. 3, each part of the semiconductor light emitting device 100 divided by the position of the isolation region 112 can be regarded as an independent light emitting part (first light emitting part, second light emitting part).
- the first surface side electrode 110 has openings at positions corresponding to the phase modulation regions 104-1 and 104-2 and the second surface side electrodes 108-1 and 108-2. 110-1 and 110-2.
- the first surface side electrode 110 may be a transparent electrode instead of the electrode having the opening.
- the vertical relationship between the active layer 103 and the phase modulation layer 104 may be opposite to the vertical relationship shown in FIG. FIG. 3 also shows the common substrate layer 101, the upper light guide layer 105b, the lower light guide layer 105a, the contact layer 107, the insulating layer 109, and the antireflection layer 111. It is not necessary to have these.
- the common substrate layer 101 is made of GaAs.
- the first cladding layer 102 is made of AlGaAs.
- the active layer 103 has a multiple quantum well structure MQW (barrier layer: AlGaAs / well layer: InGaAs).
- the phase modulation layer 104 includes basic regions 104-1a and 104-2a and a plurality of different refractive index regions 104-1b and 104-2b embedded in the basic regions 104-1a and 104-2a.
- the basic regions 104-1a and 104-2a are made of GaAs.
- the plurality of different refractive index regions 104-1b and 104-2b are made of AlGaAs.
- the upper light guide layer 105b and the lower light guide layer 105a are made of AlGaAs.
- the second cladding layer 106 is made of AlGaAs.
- the contact layer 107 is made of GaAs.
- the insulating layer 109 is made of SiO 2 or silicon nitride.
- the antireflection layer 111 is made of a dielectric single layer film or a dielectric multilayer film such as silicon nitride (SiN) or silicon dioxide (SiO 2 ).
- the element body (at least the active layer 103, the phase modulation layer 104, and the first cladding layer 102) is formed on the common substrate layer 101 as described above. , Including the second cladding layer 106) (second step).
- the isolation region 112 is formed by a semiconductor layer modified by high-intensity light (electric field), a semiconductor layer insulated by any of impurity diffusion and ion implantation, or any of dry etching and wet etching It is a slit (gap).
- the plurality of different refractive index regions 104-1b and 104-2b may be holes filled with argon, nitrogen, air, or the like.
- the separation region 112 extending from the second surface 100 b toward the common substrate layer 101 does not need to penetrate the common substrate layer 101.
- the thickness of the portion where the separation region 112 is formed in the thickness of the common substrate layer 101 along the Z-axis direction between the end surface 112a on the first surface side electrode 110 side of the separation region 112 and the first surface side electrode 110).
- the shortest distance is preferably less than or equal to half the thickness of the common substrate layer 101 in order to reduce crosstalk between the light emitting portions.
- the thickness of the unformed portion of the separation region 112 is 70 ⁇ m or less. Note that the manufacturing method according to the present embodiment is also applicable to the manufacture of semiconductor light emitting devices according to second to fourth embodiments described later.
- the common substrate layer 101 and the first cladding layer 102 are doped with N-type impurities. P-type impurities are added to the second cladding layer 106 and the contact layer 107.
- the energy band gap between the first cladding layer 102 and the second cladding layer 106 is larger than the energy band gap between the upper light guide layer 105b and the lower light guide layer 105a.
- the energy band gap between the upper light guide layer 105 b and the lower light guide layer 105 a is set to be larger than the energy band gap of the multiple quantum well structure MQW of the active layer 103.
- FIG. 4 is a schematic diagram for explaining an arrangement pattern of the different refractive index regions in the phase modulation region.
- FIG. 5 is a diagram for explaining the positional relationship between the gravity center G1 of the different refractive index region and the lattice point O in the virtual square lattice. Although only twelve different refractive index regions are shown in FIG. 4, a large number of different refractive index regions are actually provided. In one example, a 704 ⁇ 704 different refractive index region is provided.
- the arrangement pattern described here is not an arrangement pattern specific to the first embodiment, and the arrangement patterns of the second to fourth embodiments described later are also the same.
- the signs representing the phase modulation region, the basic region, and the plurality of different refractive index regions are generalized, the phase modulation region is n04-m, the basic region is n04-ma, and the plurality of different refractive index regions are n04. It is represented by -mb.
- n is a number for distinguishing the embodiments (the first embodiment is “1”, the second embodiment is “2”, etc.
- m is a semiconductor light emitting element constituting one semiconductor light emitting module. It is a number for distinguishing, and “n” and “m” are both represented by an integer of 1 or more.
- the phase modulation layer n04-m includes a first refractive index basic region n04-ma and a second refractive index different refractive index region n04-mb different from the first refractive index.
- a virtual square lattice defined on the XY plane is set in the phase modulation layer n04-m.
- FIG. 4 is a schematic diagram for explaining an arrangement pattern (rotation method) of different refractive index regions in the phase modulation layer. One side of the square lattice is parallel to the X axis, and the other side is parallel to the Y axis.
- the square unit constituting region R centering on the lattice point O of the square lattice can be set two-dimensionally over a plurality of columns along the X axis and a plurality of rows along the Y axis.
- a plurality of different refractive index regions n04-mb is provided in each unit constituting region R.
- the planar shape of the different refractive index region n04-mb is, for example, a circular shape.
- the center of gravity G1 of the different refractive index region n04-mb is arranged away from the lattice point O closest to it.
- the XY plane is a plane orthogonal to the thickness direction (Z axis) of each of the semiconductor light emitting devices 100-1 and 100-2 shown in FIG. This coincides with one surface of the phase modulation layer n04-m including mb.
- Each unit constituting region R constituting the square lattice is specified by a coordinate component x (an integer of 1 or more) in the X-axis direction and a coordinate component y (an integer of 1 or more) in the Y-axis direction, and the unit constituting region R (x , Y).
- the center of the unit configuration region R (x, y), that is, the lattice point is represented by O (x, y).
- the lattice point O may be located outside the different refractive index region n04-mb, or may be included inside the different refractive index region n04-mb.
- the ratio of the area S of the different refractive index regions n04-mb occupying in one unit constituent region R is called a filling factor (FF).
- FF filling factor
- the broken lines indicated by x1 to x4 indicate the center position in the X-axis direction in the unit constituent area R
- the broken lines indicated by y1 to y3 indicate the center position in the Y-axis direction in the unit constituent area R.
- the intersections of the broken lines x1 to x4 and the broken lines y1 to y3 are the centers O (1,1) to O (3,4) of the unit constituent regions R (1,1) to R (3,4), that is, , Indicate lattice points.
- This virtual square lattice has a lattice constant of a.
- the lattice constant a is adjusted according to the emission wavelength.
- the arrangement pattern of the different refractive index region n04-mb is determined by the method described in Patent Document 1 according to the target beam projection region and the target beam projection pattern. That is, the direction in which the center of gravity G1 of each different refractive index region n04-mb is shifted from each lattice point (intersection of broken lines x1 to x4 and broken lines y1 to y3) in a virtual square lattice in the basic region n04-ma
- the arrangement pattern is determined by determining the original pattern corresponding to the projection area and the target beam projection pattern according to the phase obtained by inverse Fourier transform. The distance r (see FIG.
- FIG. 5 is a diagram for explaining an example of an arrangement pattern (rotation method) determined by the rotation method.
- FIG. 5 shows the configuration of the unit configuration region R (x, y).
- the distance r from the lattice point to the different refractive index region n04-mb is indicated by r (x, y).
- the unit constituting region R (x, y) constituting the square lattice is defined by the s axis and the t axis that are orthogonal to each other at the lattice point O (x, y).
- the s-axis is an axis parallel to the X-axis, and corresponds to the broken lines x1 to x4 shown in FIG.
- the t-axis is an axis parallel to the Y-axis and corresponds to the broken lines y1 to y3 shown in FIG.
- the angle formed between the direction from the lattice point O (x, y) toward the center of gravity G1 and the s axis is ⁇ (x, y).
- the rotation angle ⁇ (x, y) is 0 °
- the direction of the vector connecting the lattice point O (x, y) and the center of gravity G1 coincides with the positive direction of the s axis.
- the length of the vector connecting the lattice point O (x, y) and the center of gravity G1 (corresponding to the distance r) is given by r (x, y).
- the rotation angle ⁇ (x, y) around the lattice point O (x, y) of the gravity center G1 of the different refractive index region n04-mb is the target. It is set independently for each unit configuration region R according to the beam projection pattern (light image).
- the rotation angle ⁇ (x, y) has a specific value in the unit configuration region R (x, y), but is not necessarily represented by a specific function. That is, the rotation angle ⁇ (x, y) is determined from the phase term of the complex amplitude obtained by converting the target beam projection pattern onto the wave number space and performing a two-dimensional inverse Fourier transform on a certain wave number range of the wave number space.
- FIG. 6 is a diagram for explaining the relationship between the target beam projection pattern (light image) output from the semiconductor light emitting element 100 and the distribution of the rotation angle ⁇ (x, y) in the phase modulation layer n04-m. .
- the target beam projection area (the installation surface of the design optical image expressed by the coordinates (x, y, z) in the XYZ orthogonal coordinate system), which is the projection range of the target beam projection pattern, is placed on the wave number space.
- the Kx-Ky plane obtained by conversion.
- the Kx axis and the Ky axis that define the Kx-Ky plane are perpendicular to each other, and the projection direction of the target beam projection pattern is changed from the normal direction (Z-axis direction) of the first surface 100a to the first surface 100a. Is correlated with the angle with respect to the normal direction when swung up to (1) to (5).
- the specific area including the target beam projection pattern is composed of M2 (an integer greater than or equal to 1) ⁇ N2 (an integer greater than or equal to 1) image areas FR each having a square shape. .
- a virtual square lattice set on the XY plane on the phase modulation layer n04-m is configured by M1 (an integer of 1 or more) ⁇ N1 (an integer of 1 or more) unit configuration regions R. Shall be.
- M2 an integer of 1 or more
- N1 an integer of 1 or more
- the integer M2 need not match the integer M1.
- the integer N2 need not match the integer N1.
- the image region FR in the Kx-Ky plane is specified by the coordinate component k x in the Kx axis direction (an integer of 1 to M2) and the coordinate component k y in the Ky axis direction (an integer of 1 to N2).
- Each of (k x , k y ) is a unit component region R identified by a coordinate component x in the X-axis direction (an integer from 1 to M1) and a coordinate component y in the Y-axis direction (an integer from 1 to N1).
- the complex amplitude F (x, y) in the unit configuration region R (x, y) obtained by two-dimensional inverse Fourier transform to (x, y) is given by the following equation (8), where j is an imaginary unit.
- the amplitude term in the complex amplitude F (x, y) of the unit configuration region R (x, y) is A ( The distribution of x, y) corresponds to the intensity distribution on the XY plane.
- the phase term in the complex amplitude F (x, y) of the unit configuration region R (x, y) is expressed as the distribution of P (x, y), Corresponds to the phase distribution on the -Y plane.
- the distribution of the rotation angle ⁇ (x, y) of the unit configuration region R (x, y) corresponds to the rotation angle distribution on the XY plane.
- FIG. 6 shows four quadrants with the center Q as the origin.
- FIG. 6 shows, as an example, a case where a light image is obtained in the first quadrant and the third quadrant is shown, but it is also possible to obtain images in the second quadrant and the fourth quadrant, or all quadrants.
- a point-symmetric pattern with respect to the origin is obtained.
- FIG. 6 shows, as an example, a case where a character “A” is obtained in the third quadrant and a pattern obtained by rotating the character “A” 180 ° in the first quadrant is obtained.
- a rotationally symmetric optical image for example, a cross, a circle, a double circle, etc.
- they are overlapped and observed as one optical image.
- the beam projection pattern (light image) output from the semiconductor light emitting device 100 is a spot, a spot group consisting of three or more points, a straight line, a cross, a line drawing, a lattice pattern, a photograph, a striped pattern, CG (computer graphics), and characters.
- the optical image corresponds to the designed optical image (original image) expressed by at least one of the above.
- the rotation angle ⁇ (x, y) of the different refractive index region n04-mb in the unit configuration region R (x, y) is determined by the following procedure.
- the center of gravity G1 of the different refractive index region n04-mb is only the distance r (value of r (x, y)) from the lattice point O (x, y). They are placed apart.
- the different refractive index regions n04-mb are arranged in the unit configuration region R (x, y) so that the rotation angle ⁇ (x, y) satisfies the following relationship.
- ⁇ (x, y) C ⁇ P (x, y) + B
- C proportional constant, for example 180 ° / ⁇
- B Arbitrary constant, for example 0 Note that the proportionality constant C and the arbitrary constant B are the same value for all unit constituent regions R.
- a pattern formed on the Kx-Ky plane projected on the wave number space is converted into a unit configuration region R (x, Y on the XY plane on the phase modulation layer n04-m. y) is subjected to two-dimensional inverse Fourier transform, and the rotation angle ⁇ (x, y) corresponding to the phase term P (x, y) of the complex amplitude F (x, y) is converted into the unit configuration region R (x, y).
- ⁇ (x, y) corresponding to the phase term P (x, y) of the complex amplitude F (x, y) is converted into the unit configuration region R (x, y).
- the far-field image of the laser beam after the two-dimensional inverse Fourier transform can be a single or multiple spot shape, circular shape, linear shape, character shape, double annular shape, or Laguerre Gaussian beam shape.
- the shape can be taken. Since the target beam projection pattern is represented by wave number information in the wave number space (on the Kx-Ky plane), a bitmap image in which the target beam projection pattern is represented by two-dimensional position information, etc. In this case, it is preferable to perform two-dimensional inverse Fourier transform after first converting to wave number information.
- the intensity distribution (the amplitude term A (x, y) on the XY plane) Distribution
- the phase distribution (the distribution of the phase term P (x, y) on the XY plane) It can be calculated by using the angle function of MATLAB.
- the arrangement pattern of the different refractive index regions n04-mb is determined, light of the target beam projection region and the target beam projection pattern can be output from the first surface 100a of the semiconductor light emitting device 100 to the beam projection region.
- the target beam projection pattern can be arbitrarily determined by the designer, and can be a spot, a spot group consisting of three or more points, a straight line, a line drawing, a cross, a figure, a photograph, CG (computer graphics), a character, and the like.
- all the different refractive index regions n04-mb have the same figure, the same area, and / or the same distance r.
- the plurality of different refractive index regions n04-b may be formed so as to be superposed by a translation operation or a combination of a translation operation and a rotation operation. In this case, generation of noise light and zero-order light that becomes noise in the beam projection region can be suppressed.
- the 0th-order light is light that is output in parallel with the Z-axis direction, and is light that is not phase-modulated in the phase modulation layer n04-m.
- FIG. 7 shows an example of the phase distribution of the complex amplitude distribution obtained by inverse Fourier transform of the target beam projection pattern and the corresponding original pattern.
- FIG. 7A shows an example of a target beam projection pattern obtained when a driving current is supplied from the second surface side electrode 108-1
- FIG. 7B shows an example of a driving current from the second surface side electrode 108-2.
- An example of a target beam projection pattern obtained when supplied is shown.
- FIGS. 7 (c) and 7 (d) show complex amplitude distributions obtained by inverse Fourier transform of the original patterns corresponding to the beam projection patterns in FIGS. 7 (a) and 7 (b), respectively.
- the phase distribution of is shown.
- FIG. 7C and FIG. 7D are composed of elements of 704 ⁇ 704, and represent an angle distribution of 0 to 2 ⁇ depending on color shading. The black part represents the angle 0.
- FIG. 8 is a block diagram illustrating a configuration of a light emitting device including the semiconductor light emitting element 100.
- the light emitting device 140 includes the semiconductor light emitting element 100, a power supply circuit 141, a control signal input circuit 142, and a drive circuit 143.
- the power supply circuit 141 supplies power to the drive circuit 143 and the semiconductor light emitting element 100.
- the control signal input circuit 142 transmits a control signal supplied from the outside of the light emitting device 140 to the drive circuit 143.
- the drive circuit 143 supplies a drive current to the semiconductor light emitting element 100.
- the drive circuit 143 and the semiconductor light emitting device 100 are connected by two drive lines 144-1 and 144-2 for supplying a drive current and one common potential line 145.
- the drive lines 144-1 and 144-2 are connected to the second surface side electrodes 108-1 and 108-2, respectively.
- the common potential line 145 is connected to the first surface side electrode 110.
- the semiconductor light emitting device 100 shown above the drive circuit 143 and the semiconductor light emitting device 100 shown below the drive circuit 143 are respectively the first surface and the second surface of one semiconductor light emitting device 100. Represents a surface.
- the drive lines 144-1 and 144-2 may be driven alternatively or simultaneously according to the application.
- the drive circuit 143 may be configured separately from the semiconductor light emitting element 100 or may be integrally formed on the common substrate layer 101 of the semiconductor light emitting element 100.
- the light emitting device 140 including the semiconductor light emitting element 100 configured as described above operates as follows. That is, a drive current is supplied from the drive circuit 143 between any of the drive lines 144-1 and 144-2 and the common potential line 145. In the light emitting portion corresponding to the second surface side electrode connected to the drive line supplied with the drive current, recombination of electrons and holes occurs in the active layer 103, and the active layer 103 in the light emitting portion emits light. The light obtained by the light emission is efficiently confined by the first cladding layer 102 and the second cladding layer 106.
- the light emitted from the active layer 103 enters the corresponding phase modulation region, and a predetermined mode is formed by the confinement effect by two-dimensional feedback by the phase modulation region.
- a predetermined mode is formed by the confinement effect by two-dimensional feedback by the phase modulation region.
- the light incident on the phase modulation region oscillates in a predetermined mode.
- the light having a predetermined oscillation mode undergoes phase modulation according to the arrangement pattern of the different refractive index regions, and the light subjected to the phase modulation is the first surface side as light expressing a beam projection pattern according to the arrangement pattern.
- the light is emitted from the electrode side to the outside (beam projection region).
- the semiconductor light emitting device 100 is a single device including the phase modulation layer 104 having a pair of phase modulation regions 104-1 and 104-2. Therefore, unlike a configuration in which a plurality of semiconductor light emitting elements each having one phase modulation region (phase modulation layer) are arranged on the support substrate, a process in which the plurality of semiconductor light emitting elements are arranged on the support substrate is necessary. And not. Therefore, according to this embodiment, the irradiation of the light of the target beam projection pattern to the target beam projection area is easily and highly accurately realized.
- the active layer 103, the phase modulation layer 104, the first cladding layer 102, the second cladding layer 106, and the common substrate layer 101 have the phase modulation region 104-1 when viewed from the Z-axis direction.
- 104-2 is provided with a separation region 112 for electrically and optically separating the corresponding regions.
- the adjacent phase modulation regions 104-1 and 104-2 are electrically and optically separated by the separation region 112, so that the occurrence of crosstalk between the adjacent phase modulation regions 104-1 and 104-2 is suppressed. Is done. As a result, irradiation of the light of the desired beam projection pattern to the desired beam projection region is realized with higher accuracy.
- the beam projection regions are equal even when the drive current is supplied from any of the second surface side electrodes 108-1 and 108-2.
- An arrangement pattern may be set (however, the beam projection pattern is arbitrary). With such a configuration, various applications other than the application example (application example in which a laser beam is scanned with respect to an object) of the semiconductor light emitting device disclosed in Patent Document 1 are possible.
- both the arrangement pattern in the first phase modulation area 104-1 and the arrangement pattern in the second phase modulation area 104-2 are the same beam projection area and the same beam projection pattern. Is set to be obtained.
- the beam projection pattern is, for example, a beam projection pattern having uniform brightness over the whole or part of the beam projection area.
- a drive current is supplied from both the second surface side electrodes 108-1 and 108-2.
- dark illumination is sufficient, either of the second surface side electrodes 108-1 and 108-2 is used.
- a drive current is supplied from only one of them.
- both the arrangement pattern in the first phase modulation area 104-1 and the arrangement pattern in the second phase modulation area 104-2 have the same beam projection pattern in the same beam projection area. It is set to be obtained.
- the beam projection area is matched with the position where the hole of the workpiece is to be drilled, and the beam projection pattern is a pattern of the shape of the hole to be drilled.
- a pulse current is alternately supplied from both of the second surface side electrodes 108-1 and 108-2. In this case, the pulse interval of each light emitting part can be increased. For this reason, it is possible to obtain a higher peak output from each light emitting unit, and it is possible to obtain a larger output.
- the phase modulation regions 104-1 and 104- are set so that the beam projection patterns are equal even when the drive current is supplied from any of the second surface side electrodes 108-1 and 108-2.
- the arrangement pattern in each of the two may be determined (however, the beam projection area is arbitrary).
- various applications other than the application example (application example in which the laser beam is scanned with respect to the object) of the semiconductor light emitting element disclosed in Patent Document 1 are possible.
- the second embodiment is an embodiment in which there are three or more pairs of phase modulation regions and second surface side electrodes that are two (a pair) in the first embodiment, and they are arranged one-dimensionally.
- the second embodiment is an embodiment in which the number of the light emitting units, which was two in the first embodiment, is increased to three or more and the light emitting units are arranged one-dimensionally. Except for this point, the second embodiment is the same as the first embodiment.
- FIG. 9 is a view of the semiconductor light emitting device 200 according to the second embodiment as viewed from the first surface side.
- FIG. 10 is a view of the semiconductor light emitting device 200 as viewed from the second surface side.
- FIG. 11 is a cross-sectional view taken along line XX of FIGS. 9 to 11 show an example in which five light emitting units (first light emitting unit to fifth light emitting unit) are arranged in a straight line, but the number of light emitting units may be other than five.
- the one-dimensional arrangement may be on a curve.
- the semiconductor light emitting device 200 has a first surface 200a and a second surface 200b, and outputs light from the first surface 200a as a light emitting surface.
- the second surface 200b functions as a support surface.
- the semiconductor light emitting device 200 includes a common substrate layer 201, an active layer 203, a phase modulation layer 204, a first cladding layer 202, a second cladding layer 206, and a plurality of second surface side electrodes 208-1 to 208-. 5 and the first surface side electrode 210.
- the phase modulation layer 204 includes a plurality of phase modulation regions 204-1 to 204-5 that are optically coupled to the active layer 203.
- a laminated structure is configured by at least the active layer 203 and the phase modulation layer 204 including the plurality of phase modulation regions 204-1 to 204-5.
- the first cladding layer 202 is located on the side where the first surface 200a is disposed with respect to the laminated structure (including at least the active layer 203 and the phase modulation layer 204).
- the second cladding layer 206 is located on the side where the second surface 200b is disposed with respect to the stacked structure (including at least the active layer 203 and the phase modulation layer 204).
- the second surface side electrodes 208-1 to 208-5 are on the side where the second surface 200b is disposed with respect to the second cladding layer 206, and positions corresponding to the phase modulation regions 204-1 to 204-5, respectively. Is arranged.
- the first surface side electrode 210 is located on the side where the first surface 200 a is disposed with respect to the first cladding layer 202.
- the phase modulation regions 204-1 to 204-5 respectively include basic regions 204-1a to 204-5a having a first refractive index and a plurality of different refractive index regions having a second refractive index different from the first refractive index. 204-1b to 204-5b.
- the plurality of different refractive index regions 204-1b to 204-5b are locations where the center of gravity G1 is shifted by a predetermined distance r from each lattice point O in the virtual square lattice in the basic regions 204-1a to 204-5a.
- the arrangement pattern of the different refractive index regions 204-1b to 204-5b in each of the phase modulation regions 204-1 to 204-5 is the second surface side electrode 208-1 corresponding to the phase modulation regions 204-1 to 204-5.
- the beam projection pattern expressed by the light output from the first surface 200a when the drive current is supplied from ⁇ 208-5 and the beam projection that is the projection range of the beam projection pattern are the target beam projection pattern and the target beam. It is set to be a projection area.
- the beam projection area of the light output when the driving current is supplied from the second surface side electrodes 208-1 to 208-5 may be all the same, or at least a part is different from the others. Also good. Further, the beam projection pattern of the light output when the drive current is supplied from the second surface side electrodes 208-1 to 208-5 may be all the same, or at least partly different from the others. It may be.
- the active layer 203, the phase modulation layer 204, the first cladding layer 202, the second cladding layer 206, and the common substrate layer 201 reach the common substrate layer 201 from the second surface 200b toward the common substrate layer 201.
- a separation region 212 extending up to is provided.
- the isolation region 212 overlaps with the phase modulation regions 204-1 to 204-5 when viewed from the Z-axis direction (stacking direction), the active layer 203, the first cladding layer 202, the second cladding layer 206, and the first cladding layer.
- 202 and the second cladding layer 206 respectively extend from the second surface 200b toward the common substrate layer 201 so as to electrically and optically separate corresponding regions.
- the thickness of the portion of the common substrate layer 201 positioned below the isolation region 212 is Z It is less than half of the thickness of the common substrate layer 201 along the axial direction, and typically less than 70 ⁇ m.
- each part of the semiconductor light emitting device 100 divided by the position of the isolation region 212 can be regarded as an independent light emitting part (first light emitting part to fifth light emitting part).
- the manufacturing process of the separation region 212 is the same as that in the first embodiment.
- the first surface side electrode 210 has openings at positions corresponding to the phase modulation regions 204-1 to 204-5 and the second surface side electrodes 208-1 to 208-5. 210-1 to 210-5.
- the first surface side electrode 210 may be a transparent electrode instead of an electrode having an opening.
- the vertical relationship between the active layer 203 and the phase modulation layer 204 may be opposite to the vertical relationship shown in FIG. FIG. 11 also shows the common substrate layer 201, the upper light guide layer 205b, the lower light guide layer 205a, the contact layer 207, the insulating layer 209, and the antireflection layer 211. It is not necessary to have these.
- the manufacturing method including the main processes excluding the manufacturing process of each layer, each region, the region, and the separation region described above is based on the description in Patent Document 1 as in the first embodiment. Those skilled in the art can appropriately select, but some examples are shown below. That is, an example of the material or structure of each layer shown in FIG. 11 is as follows.
- the common substrate layer 201 is made of GaAs.
- the first cladding layer 202 is made of AlGaAs.
- the active layer 203 has a multiple quantum well structure MQW (barrier layer: AlGaAs / well layer: InGaAs).
- the phase modulation layer 204 includes basic regions 204-1a to 204-5a and a plurality of different refractive index regions 204-1b to 204-5b embedded in the basic regions 204-1a to 204-5a.
- the basic regions 204-1a to 204-5a are made of GaAs.
- the plurality of different refractive index regions 204-1b to 204-5b are made of AlGaAs.
- the upper light guide layer 205b and the lower light guide layer 205a are made of AlGaAs.
- the second cladding layer 206 is made of AlGaAs.
- the contact layer 207 is made of GaAs.
- the insulating layer 209 is made of SiO 2 or silicon nitride.
- the antireflection layer 211 is made of a dielectric single layer film or dielectric multilayer film such as silicon nitride (SiN) or silicon dioxide (SiO 2 ).
- the isolation region 212 is formed by a semiconductor layer modified by high-intensity light (electric field), a semiconductor layer insulated by any of impurity diffusion and ion implantation, or any of dry etching and wet etching It is a slit (gap).
- a specific method of modification by high intensity light (electric field) there are, for example, processing by a nanosecond laser and processing by an ultrashort pulse laser.
- the plurality of different refractive index regions 204-1b to 204-5b may be holes filled with argon, nitrogen, air, or the like.
- the common substrate layer 201 and the first cladding layer 202 are doped with N-type impurities. P-type impurities are added to the second cladding layer 206 and the contact layer 207.
- the energy band gap between the first cladding layer 202 and the second cladding layer 206 is larger than the energy band gap between the upper light guide layer 205b and the lower light guide layer 205a.
- the energy band gap of the upper light guide layer 205b and the lower light guide layer 205a is set to be larger than the energy band gap of the multiple quantum well structure MQW of the active layer 203.
- FIG. 12 and FIG. 13 show the phase distribution of the complex amplitude distribution obtained by performing inverse Fourier transform on the target beam projection pattern and the corresponding original pattern in the present embodiment and the third embodiment described later.
- An example is shown.
- 12A to 12C show target beam projection patterns obtained when a drive current is supplied from the second surface side electrodes of the first light emitting unit, the third light emitting unit, and the fifth light emitting unit, respectively.
- An example is shown.
- 12D to 12F show complex amplitude distributions obtained by performing inverse Fourier transform on the original patterns corresponding to the beam projection patterns in FIGS. 12A to 12C, respectively. The phase distribution of is shown.
- FIGS. 12A to 12C show the phase distribution of the complex amplitude distribution obtained by performing inverse Fourier transform on the target beam projection pattern and the corresponding original pattern in the present embodiment and the third embodiment described later.
- 12A to 12C show target beam projection patterns obtained when a drive current is supplied from the second surface side electrodes of the first light emitting unit,
- FIGS. 13 (d) to 13 (f) show complex amplitude distributions obtained by performing inverse Fourier transform on the original patterns corresponding to the beam projection patterns in FIGS. 13 (a) to 13 (c), respectively.
- the phase distribution of is shown.
- 12 (d) to 12 (f) and FIGS. 13 (d) to 13 (f) are each composed of elements of 704 ⁇ 704, and the distribution of angles from 0 to 2 ⁇ is represented by the color shade. Represents.
- the black part represents the angle 0.
- FIG. 14 is a block diagram illustrating a configuration of a light emitting device including the semiconductor light emitting element 200.
- the light emitting device 240 includes a semiconductor light emitting element 200, a power supply circuit 241, a control signal input circuit 242, and a drive circuit 243.
- the power supply circuit 241 supplies power to the drive circuit 243 and the semiconductor light emitting element 200.
- the control signal input circuit 242 transmits a control signal supplied from the outside of the light emitting device 240 to the drive circuit 243.
- the drive circuit 243 supplies a drive current to the semiconductor light emitting element 200.
- the drive circuit 243 and the semiconductor light emitting element 200 are connected by a plurality of drive lines 244-1 to 244-5 for supplying a drive current and one common potential line 245.
- the drive lines 244-1 to 244-5 are connected to the second surface side electrodes 208-1 to 208-5, respectively.
- the common potential line 245 is connected to the first surface side electrode 210.
- the semiconductor light emitting element 200 shown above the drive circuit 243 and the semiconductor light emitting element 200 shown below the drive circuit 243 are respectively the first surface and the second surface of one semiconductor light emitting element 200. Represents a surface.
- the drive lines 244-1 to 244-5 may be driven alternatively according to the application, or at least two may be driven simultaneously.
- the drive circuit 243 may be configured separately from the semiconductor light emitting element 200 or may be integrally formed on the common substrate layer 201 of the semiconductor light emitting element 200.
- the light emitting device 240 including the semiconductor light emitting element 200 configured as described above operates as follows. That is, a drive current is supplied from the drive circuit 243 to any one of the drive lines 244-1 to 244-5 and the common potential line 245. In the light emitting portion corresponding to the second surface side electrode connected to the drive line supplied with the drive current, recombination of electrons and holes occurs in the active layer 203, and the active layer 203 in the light emitting portion emits light. The light obtained by the light emission is efficiently confined by the first cladding layer 202 and the second cladding layer 206. The light emitted from the active layer 203 enters the corresponding phase modulation region, and forms a predetermined mode by the confinement effect by two-dimensional feedback by the phase modulation region.
- the light incident on the phase modulation region oscillates in a predetermined mode.
- the light having a predetermined oscillation mode undergoes phase modulation according to the arrangement pattern of the different refractive index regions, and the light subjected to the phase modulation is the first surface side as light expressing a beam projection pattern according to the arrangement pattern.
- the light is emitted from the electrode side to the outside (beam projection region).
- the semiconductor light emitting device 200 is a single device including the phase modulation layer 204 having a plurality of phase modulation regions 204-1 to 204-5. Therefore, unlike a configuration in which a plurality of semiconductor light emitting elements each having one phase modulation region (phase modulation layer) are arranged on the support substrate, a process in which the plurality of semiconductor light emitting elements are arranged on the support substrate is necessary. And not. Therefore, the irradiation of the light of the target beam projection pattern to the target beam projection area can be realized easily and with high accuracy.
- the active layer 203, the phase modulation layer 204, the first cladding layer 202, the second cladding layer 206, and the common substrate layer 201 are moved from the second surface 200b toward the common substrate layer 201.
- a separation region 212 extending until reaching the common substrate layer 201 is provided.
- the adjacent phase modulation regions 204-1 to 204-5 are electrically and optically separated by the separation region 212, so that the occurrence of crosstalk between the adjacent phase modulation regions 204-1 to 204-5 is suppressed. Is done. As a result, irradiation of the light of the desired beam projection pattern to the desired beam projection region is realized with higher accuracy.
- the phase modulation areas 204-1 to 204- are set so that the beam projection areas become equal when the drive current is supplied from any of the second surface side electrodes 208-1 to 208-5. 5 may be set (however, the beam projection pattern is arbitrary). In the case of such a configuration, various applications other than the application example (application example in which a laser beam is scanned with respect to an object) of the semiconductor light emitting element disclosed in Patent Document 1 are possible.
- the application (A) in the second embodiment there is an application in which the illumination shown as the application (A) in the first embodiment is changed so as to be switchable in multiple stages.
- the laser processing shown as application (c) in the first embodiment is changed to sequentially drive a plurality of second surface side electrodes.
- the phase modulation regions 204-1 to 204- are set so that the beam projection patterns are equal even when the drive current is supplied from any of the second surface side electrodes 208-1 to 208-5. 5 may be set (however, the beam projection area is arbitrary).
- an application similar to the application example of the semiconductor light emitting device disclosed in Patent Document 1 application example in which the laser beam is scanned with respect to the object
- Various applications are also possible.
- applications different from the application example shown in Patent Document 1 in addition to the above-mentioned applications (a) to (c), it is possible to apply to an illumination of a type that irradiates an arbitrary part at a desired timing. Become.
- the third embodiment is an embodiment in which the one-dimensional arrangement of the phase modulation region and the second surface side electrode in the second embodiment is changed to a two-dimensional arrangement.
- the second embodiment is an embodiment in which the one-dimensional arrangement of the plurality of light emitting units is changed to a two-dimensional arrangement as in the first embodiment. Except for such a change, the second embodiment. It is the same.
- FIGS. 15 to 17 the structure of the semiconductor light emitting device 300 according to the third embodiment will be described.
- 15 is a diagram of the semiconductor light emitting device 300 according to the third embodiment as viewed from the first surface side
- FIG. 16 is a diagram of the semiconductor light emitting device 300 as viewed from the second surface side
- FIG. FIG. 16 is a sectional view taken along line XVI-XVI.
- 15 to 17 show an example in which 15 light emitting units (first light emitting unit to 15th light emitting unit) are arranged in 3 rows and 5 columns, but the number of light emitting units is other than 15.
- the two-dimensional arrangement may be arbitrary.
- the semiconductor light emitting device 300 has a first surface 300a and a second surface 300b, and outputs light from the first surface 300a as a light emitting surface.
- the second surface 300b functions as a support surface.
- the semiconductor light emitting device 300 includes a common substrate layer 301, an active layer 303, a phase modulation layer 304, a first cladding layer 302, a second cladding layer 306, and a plurality of second surface side electrodes 308-1 to 308-. 15 and a first surface side electrode 310.
- the phase modulation layer 304 includes a plurality of phase modulation regions 304-1 to 304-15 that are optically coupled to the active layer 303.
- a laminated structure is constituted by at least the active layer 303 and the phase modulation layer 304 including the plurality of phase modulation regions 304-1 to 304-15.
- the first cladding layer 302 is located on the side where the first surface 300a is disposed with respect to the laminated structure (including at least the active layer 303 and the phase modulation layer 304).
- the second cladding layer 306 is located on the side where the second surface 300b of the laminated structure (including at least the active layer 303 and the phase modulation layer 304) is disposed.
- the second surface side electrodes 308-1 to 308-15 are on the side where the second surface 300b is disposed with respect to the second cladding layer 306, and positions corresponding to the phase modulation regions 304-1 to 304-15, respectively. Is arranged.
- the first surface side electrode 310 is located on the side where the first surface 300 a is disposed with respect to the first cladding layer 302.
- the phase modulation regions 304-1 to 304-15 each include a plurality of different refractive index regions 304 having a second refractive index different from the basic regions 304-1a to 304-15a having the first refractive index. -1b to 304-15b.
- the plurality of different refractive index regions 304-1b to 304-15b are locations where the center of gravity G1 is shifted from each lattice point O in the virtual square lattice in the basic regions 304-1a to 304-15a by a predetermined distance r.
- the arrangement pattern of the different refractive index regions 304-1b to 304-15b in each of the phase modulation regions 304-1 to 304-15 is the second surface side electrode 308- corresponding to the phase modulation regions 304-1 to 304-15.
- a beam projection pattern expressed by light output from the first surface 300a when a drive current is supplied from 1 to 308-15 and a beam projection area that is a projection range of the beam projection pattern are a target beam projection pattern and It is set to coincide with the target beam projection area.
- the beam projection areas of the light output when the drive current is supplied from the second surface side electrodes 308-1 to 308-15 may all be the same, or at least part of them may be different from the others. Also good. Also, the beam projection pattern of the light output when the drive current is supplied from the second surface side electrodes 308-1 to 308-15 may be all the same, or at least partly different from the others. It may be.
- the active layer 303, the phase modulation layer 304, the first cladding layer 302, the second cladding layer 306, and the common substrate layer 301 reach the common substrate layer 301 from the second surface 300b toward the common substrate layer 301.
- a separation region 312 extending up to is provided.
- the isolation region 312 is an active layer 303, a first cladding layer 302, a second cladding layer 306, and a first cladding layer that overlap with the phase modulation regions 304-1 to 204-5 when viewed from the Z-axis direction (stacking direction).
- 302 and the second cladding layer 306 respectively extend from the second surface 300b toward the common substrate layer 301 so as to electrically and optically separate corresponding regions.
- the thickness of the portion of the common substrate layer 301 located below the isolation region 312 is Z It is less than half of the thickness of the common substrate layer 201 along the axial direction, and typically less than 70 ⁇ m.
- each part of the semiconductor light emitting device 300 divided by the position of the isolation region 312 can be regarded as an independent light emitting part (first light emitting part to 15th light emitting part).
- the manufacturing process of the separation region 312 is the same as that in the first embodiment.
- the first surface side electrode 310 has openings at positions corresponding to the phase modulation regions 304-1 to 304-15 and the second surface side electrodes 308-1 to 308-15. 310-1 to 310-15.
- the first surface side electrode 310 may be a transparent electrode instead of the electrode having the opening.
- the vertical relationship between the active layer 303 and the phase modulation layer 304 may be opposite to the vertical relationship shown in FIG. FIG. 17 also shows the common substrate layer 301, the upper light guide layer 305b, the lower light guide layer 305a, the contact layer 307, the insulating layer 309, and the antireflection layer 311. It is not necessary to have these.
- the manufacturing method including the main processes excluding the manufacturing process of each layer, each region, the region, and the separation region described so far are the same as those in the first embodiment and the second embodiment.
- a person skilled in the art can select as appropriate based on the description, but some examples are shown below. That is, an example of the material or structure of each layer shown in FIG. 17 is as follows.
- the common substrate layer 301 is made of GaAs.
- the first cladding layer 302 is made of AlGaAs.
- the active layer 303 has a multiple quantum well structure MQW (barrier layer: AlGaAs / well layer: InGaAs).
- the phase modulation layer 304 includes basic regions 304-1a to 304-15a and a plurality of different refractive index regions 304-1b to 304-15 embedded in the basic regions 304-1a to 304-15a.
- the basic regions 304-1a to 304-15a are made of GaAs.
- the plurality of different refractive index regions 304-1b to 304-15b are made of AlGaAs.
- the upper light guide layer 305b and the lower light guide layer 305a are made of AlGaAs.
- the second cladding layer 306 is made of AlGaAs.
- the contact layer 307 is made of GaAs.
- the insulating layer 309 is made of SiO 2 or silicon nitride.
- the antireflection layer 311 is made of a dielectric single layer film or a dielectric multilayer film such as silicon nitride (SiN) or silicon dioxide (SiO 2 ).
- the isolation region 312 is a semiconductor layer modified by high-intensity light (electric field), a semiconductor layer insulated by one of impurity diffusion and ion implantation, or a slit (gap) formed by dry etching or wet etching. It is.
- high intensity light there are, for example, processing by a nanosecond laser and processing by an ultrashort pulse laser.
- the plurality of different refractive index regions 304-1b to 304-15b may be holes filled with argon, nitrogen, air, or the like.
- an N-type impurity is added to the common substrate layer 301 and the first cladding layer 302.
- P-type impurities are added to the second cladding layer 306 and the contact layer 307.
- the energy band gap between the first cladding layer 302 and the second cladding layer 306 is larger than the energy band gap between the upper light guide layer 305b and the lower light guide layer 305a.
- the energy band gap between the upper light guide layer 305 b and the lower light guide layer 305 a is set to be larger than the energy band gap of the multiple quantum well structure MQW of the active layer 303.
- FIG. 18 is a block diagram illustrating a configuration of a light emitting device including the semiconductor light emitting element 300.
- the light emitting device 340 includes a semiconductor light emitting element 300, a power supply circuit 341, a control signal input circuit 342, and a drive circuit 343.
- the power supply circuit 341 supplies power to the drive circuit 343 and the semiconductor light emitting element 300.
- the control signal input circuit 342 transmits a control signal supplied from the outside of the light emitting device 340 to the drive circuit 343.
- the drive circuit 343 supplies a drive current to the semiconductor light emitting element 300.
- the drive circuit 343 and the semiconductor light emitting element 300 are connected by a plurality of drive lines 344-1 to 344-15 for supplying a drive current and one common potential line 345.
- the drive lines 344-1 to 344-15 are connected to the second surface side electrodes 308-1 to 308-15, respectively, and the common potential line 345 is connected to the first surface side electrode 310.
- the semiconductor light emitting device 300 shown above the drive circuit 343 and the semiconductor light emitting device 300 shown below the drive circuit 343 are respectively the first surface and the second surface of one semiconductor light emitting device 300. Represents a surface.
- the drive lines 344-1 to 344-15 may be driven alternatively according to the application, or at least two may be driven simultaneously.
- the drive circuit 343 may be configured separately from the semiconductor light emitting element 300 or may be integrally formed on the common substrate layer 301 of the semiconductor light emitting element 300.
- the light emitting device 340 including the semiconductor light emitting element 300 configured as described above operates as follows. That is, a drive current is supplied from the drive circuit 343 between any of the drive lines 344-1 to 344-15 and the common potential line 345. In the light emitting portion corresponding to the second surface side electrode connected to the driving line supplied with the driving current, recombination of electrons and holes occurs in the active layer 303, and the active layer 303 in the light emitting portion emits light. The light obtained by the light emission is efficiently confined by the first cladding layer 302 and the second cladding layer 306. The light emitted from the active layer 303 enters the corresponding phase modulation region, and forms a predetermined mode by the confinement effect by two-dimensional feedback by the phase modulation region.
- the light incident on the phase modulation region oscillates in a predetermined mode.
- the light that has formed a predetermined oscillation mode undergoes phase modulation according to the arrangement pattern of the different refractive index regions, and the light subjected to the phase modulation is first as light having a beam projection region and a beam projection pattern according to the arrangement pattern.
- the light is emitted from the surface side electrode side to the outside.
- the semiconductor light emitting device 300 is a single device including the phase modulation layer 304 having a plurality of phase modulation regions 304-1 to 304-15. Therefore, unlike a configuration in which a plurality of semiconductor light emitting elements each having one phase modulation region (phase modulation layer) are arranged on the support substrate, a process in which the plurality of semiconductor light emitting elements are arranged on the support substrate is necessary. And not. Therefore, the irradiation of the light of the target beam projection pattern to the target beam projection area can be realized easily and with high accuracy.
- the active substrate 303, the phase modulation layer 304, the first cladding layer 302, the second cladding layer 306, and the common substrate layer 301 are formed from the second surface 300 b toward the common substrate layer 301.
- a separation region 312 is provided that extends until it reaches the layer 301. Since the adjacent phase modulation regions 304-1 to 304-15 are electrically and optically separated by such a separation region 312, crosstalk between the adjacent phase modulation regions 304-1 to 304-15 is reduced. Occurrence is suppressed. As a result, irradiation of the light of the desired beam projection pattern to the desired beam projection region is realized with higher accuracy.
- the phase modulation areas 304-1 to 304-15 are set so that the beam projection areas are equal even when the drive current is supplied from any of the second surface side electrodes 308-1 to 308-15.
- the arrangement pattern in each may be defined.
- various applications other than the application example (application example in which a laser beam is scanned with respect to an object) of the semiconductor light emitting element disclosed in Patent Document 1 are possible. Possible applications are the same as in the second embodiment.
- the phase modulation regions 304-1 to 304- are set so that the beam projection patterns are equal even when the drive current is supplied from any of the second surface side electrodes 308-1 to 308-15.
- the arrangement pattern in each of 15 may be set.
- an application similar to the application example of the semiconductor light emitting device disclosed in Patent Document 1 application example in which the laser beam is scanned with respect to the object
- Various applications are also possible. Possible applications in this case are the same as in the second embodiment.
- the light output extracted from the first surface side in the first embodiment is changed to be extracted from the second surface side. According to this, since the light output does not pass through the common substrate layer, the absorption of the output light by the common substrate layer can be eliminated, and the attenuation of the output light and the heat generation of the common substrate layer can be prevented. Except for such a change, the second embodiment is the same as the first embodiment.
- FIG. 19 is a view of the semiconductor light emitting device 100B according to the fourth embodiment as viewed from the first surface side.
- FIG. 20 is a view of the semiconductor light emitting device 100B as viewed from the second surface side.
- FIG. 21 is a sectional view taken along line XX-XX in FIGS.
- the semiconductor light emitting device 100B has a first surface 100Ba and a second surface 100Bb, and unlike the first to third embodiments, the second surface as a light emitting surface. Light is output from 100 Bb.
- the first surface 100Ba functions as a support surface.
- the semiconductor light emitting device 100B includes a common substrate layer 101B, an active layer 103B, a phase modulation layer 104B, a first cladding layer 102B, a second cladding layer 106B, and a pair of second surface side electrodes 108B-1 and 108B-. 2 and a pair of first surface side electrodes 110B-1 and 110B-2.
- the phase modulation layer 104B has a pair of phase modulation regions 104B-1 and 104B-2 that are optically coupled to the active layer 103B.
- a laminated structure is constituted by at least the phase modulation layer 104B including the active layer 103B and the pair of phase modulation regions 104B-1 and 104B-2.
- the first cladding layer 102B is located on the side where the first surface 100Ba is disposed with respect to the stacked structure (including at least the active layer 103B and the phase modulation layer 104B).
- the second cladding layer 106B is located on the side where the second surface 100Bb is disposed with respect to the laminated structure (including at least the active layer 103B and the phase modulation layer 104B).
- the second surface side electrodes 108B-1 and 108B-2 are on the side where the second surface 100Bb is disposed with respect to the second cladding layer 106B, and positions corresponding to the phase modulation regions 104B-1 and 104B-2, respectively. Is arranged.
- the first surface side electrodes 110B-1 and 110B-2 are located on the side where the first surface 100Ba is disposed with respect to the first cladding layer 102.
- Each of the phase modulation regions 104B-1 and 104B-2 includes a plurality of different refractive index regions 104B- having a second refractive index different from the basic regions 104B-1a and 104B-1b having the first refractive index. 2a, 104B-2b.
- the plurality of different refractive index regions 104B-1b and 104B-2b are locations where the center of gravity G1 is shifted from each lattice point O in the virtual square lattice in the basic regions 104B-1a and 104-2a by a predetermined distance r.
- the arrangement pattern of the plurality of different refractive index regions 104B-1b and 104B-2b in each of the phase modulation regions 104B-1 and 104B-2 is the second surface side electrode 108B corresponding to the phase modulation region 104B-1 or 104B-2.
- -1 or 108B-2 when a drive current is supplied a beam projection pattern expressed by light output from the second surface 100Bb and a beam projection area that is a projection range of the beam projection pattern are a target beam projection pattern And the target beam projection area.
- the active layer 103B, the phase modulation layer 104B, the first cladding layer 102B, the second cladding layer 106B, and the common substrate layer 101B reach the common substrate layer 101B from the second surface 100Bb toward the common substrate layer 101B.
- a separation region 112 ⁇ / b> B extending to the top is provided.
- the isolation region 112B includes the active layer 103B, the first cladding layer 102B, the second cladding layer 106B, and the first cladding layer that overlap with the phase modulation regions 104B-1 and 104B-2 when viewed from the Z-axis direction (stacking direction).
- the corresponding regions in 102B and the second cladding layer 106B extend from the second surface 100Bb toward the common substrate layer 101B so as to electrically and optically separate the corresponding regions.
- the thickness of the portion of the common substrate layer 101B located below the isolation region 112B is equal to or less than half the thickness of the common substrate layer 101B along the Z-axis direction (stacking direction), and typically equal to or less than 70 ⁇ m.
- the first surface side electrode is divided into two.
- the two first surface side electrodes 110B-1 and 110B-2 are collectively referred to as a “first surface side electrode”. . Therefore, “the distance between the end surface 112Ba on the first surface side electrodes 110B-1 and 110B-2 side of the separation region 112B and the first surface side electrodes 110B-1 and 110B-2” (the separation region of the common substrate layer 101B).
- the thickness of the unformed portion is defined as one flat surface including the surface on which the common substrate layer 101B is disposed on both the first surface side electrode 110B-1 and the first surface side electrode 110B-2, and the end surface. Refers to the distance to 112Ba.
- each part of the semiconductor light emitting device 100B divided by the position of the isolation region 112B can be regarded as an independent light emitting part (first light emitting part, second light emitting part).
- the manufacturing process of the separation region 112B is the same as that of the first embodiment.
- the second surface side electrodes 108B-1 and 108B-2 are connected to the phase modulation regions 104B-1 and 104B-2 and the first surface side electrodes 110B-1 and 110B-2. Openings 108B-1a and 108B-2a are provided at corresponding positions.
- the second surface side electrodes 108B-1 and 108B-2 may be transparent electrodes instead of the electrodes having openings.
- the vertical relationship between the active layer 103B and the phase modulation layer 104B may be opposite to the vertical relationship shown in FIG. Further, there may be a DBR layer 120B between the common substrate layer 101B and the first cladding layer 102B for the purpose of reducing light absorption in the common substrate layer 101B.
- the DBR layer 120B may be located at other locations as long as it is between the phase modulation layer 104B and the common substrate layer 101B.
- FIG. 21 also shows the common substrate layer 101B, the upper light guide layer 105Bb, the lower light guide layer 105Ba, the contact layer 107B, the insulating layer 109, and the antireflection layer 111B. It is not necessary to have these.
- the common substrate layer 101B is made of GaAs.
- the first cladding layer 102B is made of AlGaAs.
- the active layer 103B has a multiple quantum well structure MQW (barrier layer: AlGaAs / well layer: InGaAs).
- the phase modulation layer 104B includes basic regions 104B-1a and 104B-2a and a plurality of different refractive index regions 104B-1b and 104B-2b embedded in the basic regions 104B-1a and 104B-2a.
- the basic regions 104B-1a and 104B-2a are made of GaAs.
- the plurality of different refractive index regions 104B-1b and 104B-2b are made of AlGaAs.
- the upper light guide layer 105Bb and the lower light guide layer 105Ba are made of AlGaAs.
- the second cladding layer 106B is made of AlGaAs.
- the contact layer 107B is made of GaAs.
- the insulating layer 109B is made of SiO 2 or silicon nitride.
- the antireflection layer 111B is made of a dielectric single layer film or a dielectric multilayer film such as silicon nitride (SiN) or silicon dioxide (SiO 2 ).
- the isolation region 112B is formed by a semiconductor layer modified by high-intensity light (electric field), a semiconductor layer insulated by any of impurity diffusion and ion implantation, or any of dry etching and wet etching It is a slit (gap).
- a specific method of modification by high intensity light (electric field) there are, for example, processing by a nanosecond laser and processing by an ultrashort pulse laser.
- the plurality of different refractive index regions 104B-1b and 104B-2b may be holes filled with argon, nitrogen, air, or the like.
- N-type impurities are added to the common substrate layer 101B and the first cladding layer 102B.
- a P-type impurity is added to the second cladding layer 106B and the contact layer 107B.
- the energy band gap between the first cladding layer 102B and the second cladding layer 106B is larger than the energy band gap between the upper light guide layer 105Bb and the lower light guide layer 105Ba.
- the energy band gap of the upper light guide layer 105Bb and the lower light guide layer 105Ba is set to be larger than the energy band gap of the multiple quantum well structure MQW of the active layer 103B.
- the separation regions 112, 212, 312, and 112B are provided.
- crosstalk does not become a problem. May have no separation region.
- FIGS. 4 and 5 show examples in which the different refractive index region is circular (perfect circle), the different refractive index region may have a shape other than circular.
- the shape of the plurality of different refractive index regions on the XY plane is any one of a perfect circle, a square, a regular hexagon, a regular octagon, a regular hexagon, a rectangle, and an ellipse, that is, each different refractive index.
- the shape of the region is mirror image symmetric (line symmetric)
- the center of gravity of each corresponding different refractive index region from the lattice point O of each of the plurality of unit constituting regions R constituting the virtual square lattice in the phase modulation layer is mirror image symmetric (line symmetric).
- an angle ⁇ formed by the direction toward G1 and the s-axis parallel to the X-axis can be set with high accuracy.
- the shapes of the plurality of different refractive index regions on the XY plane are shapes having no rotational symmetry of 180 ° as shown in FIGS. 22 (a) to 22 (j). Also good. Examples of shapes that do not have 180 ° rotational symmetry include the equilateral triangle shown in FIG. 22B, the right isosceles triangle shown in FIG. 22A, and the shape shown in FIG. 22C. An isosceles triangle, two circles or a part of an ellipse overlap, the shape shown in FIG. 22 (i), the egg shape shown in FIG. 22 (h), and the teardrop shape shown in FIG.
- FIG. 22 (j) The shape shown in is included. In this case, higher light output can be obtained.
- the egg-shaped shape is such that the dimension in the minor axis direction near one end along the major axis is the dimension in the minor axis direction near the other end. It is a shape obtained by deforming an ellipse so as to be smaller than that.
- the teardrop shape is obtained by deforming one end of an ellipse along the major axis into a sharp end projecting along the major axis. It is.
- the arrow shape is a shape in which one side of the rectangle forms a triangular cutout, and the side opposite to the one side forms a triangular projection.
- the semiconductor light emitting device outputs light from the first surface.
- the second surface side electrode is replaced with an electrode having an opening or a transparent
- a semiconductor light emitting element that outputs light from the second surface side may be used.
- the number of the phase modulation region, the second surface side electrode, and the first surface side electrode is two (a pair), respectively. One or more may be arranged in one or two dimensions.
- An outer region B that surrounds the outer periphery may be provided.
- the inner region A is substantially a region constituted by unit constitution regions R in which corresponding different refractive index regions are arranged.
- the outer region B is provided with a plurality of peripheral lattice point different refractive index regions, and the center of gravity of the plurality of peripheral lattice point different refractive index regions is, for example, the virtual square on the outer periphery of a virtual square lattice.
- FIG. 23 shows a modification of the phase modulation layer as viewed along the layer thickness direction (Z-axis direction).
- the outer contour represents a part of the phase modulation region.
- the inner region A surrounded by the outer region B is a phase modulation region (substantially the same as in the first to fourth embodiments) including a beam projection region and a plurality of different refractive index regions for generating a beam projection pattern.
- the phase modulation region of the phase modulation layer is configured by an inner region A and an outer region B.
- the outer region B is a region including a plurality of peripheral lattice point different refractive index regions having centroids at lattice point positions in a virtual square lattice.
- the lattice constant of the virtual square lattice in the outer region B is equal to the lattice constant of the virtual square lattice in the inner region A
- the shape and size of each peripheral lattice point different refractive index region in the outer region B It may be equal to the shape and size of the different refractive index region in the region A. According to this modification, light leakage in the in-plane direction is suppressed, and the oscillation threshold current can be reduced.
- displaced different refractive index region having a center of gravity G1 at a position shifted by a predetermined distance from each lattice point in the virtual square lattice in the basic region.
- the displacement different refractive index region may be divided into a plurality of portions so that the entire center of gravity is located at a position shifted from the respective lattice points by a predetermined distance.
- a lattice point different refractive index region may be provided on each lattice point.
- the lattice point different refractive index region is a region having a refractive index different from the refractive index of the basic region (first refractive index) in the same manner as the displacement different refractive index region. Material), or part of it may overlap with part of the displacement refractive index region.
- FIG. 24 is a diagram for explaining the positional relationship between the center of gravity of the displacement different refractive index region and the lattice point different refractive index region when a lattice point different refractive index region is provided in addition to the displacement different refractive index region.
- FIG. 25 is a diagram showing an example (rotation method) of a combination of a displacement different refractive index region and a lattice point refractive index region when a lattice point different refractive index region is provided in addition to the displacement different refractive index region.
- FIG. 26 is a diagram showing a modification (rotation method) in the case where a lattice point different refractive index region is provided in addition to the displacement different refractive index region.
- O represents a lattice point
- G1 represents the center of gravity of the displacement refractive index region
- G2 represents the center of gravity of the lattice point different refractive index region.
- the positional relationship between the center of gravity G1 of the displacement refractive index region n04-mb and the lattice point O is the same as that in FIG. 5, but in FIG. n04-mc is provided.
- the center of gravity G2 of the lattice point different refractive index region n04-mc overlaps with the lattice point O, but the center of gravity G2 does not necessarily have to be above the lattice point O as shown in FIG. .
- the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc are both circular and do not overlap each other, but the combination of both is not limited to this.
- FIG. 25A is a combination of FIG. FIG. 25 (b) shows a combination of squares of the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc.
- FIG. 25C shows a combination in which the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc are both circular, but a part of both overlaps each other.
- FIG. 25A is a combination of FIG. FIG. 25 (b) shows a combination of squares of the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc.
- FIG. 25C shows a combination in which the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc are both circular, but a part of both overlaps each other.
- FIG. 25 (d) shows a combination in which the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc are both square and a part of both overlaps.
- FIG. 25 (e) arbitrarily rotates the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc of FIG. 25 (d) around the center of gravity G1, G2 (lattice point O). The combination is such that they do not overlap each other.
- the displacement different refractive index region n04-mb is a triangle and the lattice point different refractive index region n04-mc is a combination of squares.
- FIG. 25 (g) arbitrarily rotates the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc of FIG. 25 (f) around the respective centroids G1 and G2 (lattice points O). The combination is such that they do not overlap each other.
- FIG. 25H shows a combination in which the displacement different refractive index region n04-mb of FIG. 25A is divided into two circular regions.
- FIG. 25 (i) shows a combination in which the displacement different refractive index region n04-mb is divided into a square and a triangle, and the lattice point different refractive index region n04-mc is a triangle.
- the entire different refractive index region including both of them does not have a rotational symmetry of 180 °, so that a higher light output can be obtained. Can do.
- the shape of the different refractive index region (including the peripheral grating point different refractive index region and the grating point different refractive index region) is a shape having a straight side
- the direction of the side is set to the common substrate layer. It is desirable to align with a specific plane orientation of the crystal to be formed. This makes it easy to control the shape of the holes when the refractive index region is filled with argon, nitrogen, air, or the like, and suppresses defects in the crystal layer that grows on the holes. can do.
- the shape and number of the different refractive index regions (including the peripheral grating point different refractive index region and the grating point different refractive index region) provided corresponding to each lattice point are not necessarily the same in one phase modulation region. There is no need. As shown in FIG. 27 (second modification of the phase modulation layer n04-m shown in FIG. 4), the shape and number of different refractive index regions may be different for each lattice point.
- the arrangement pattern of the different refractive index regions n04-mb in the phase modulation layer n04-m is determined by the on-axis shift method. Even when the axial shift method is applied in place of the rotation method described above as the method for determining the arrangement pattern of the different refractive index regions n04-mb in the phase modulation layer n04-m, the obtained phase modulation layer is the same as that described above.
- the present invention is applied to the semiconductor light emitting module according to various embodiments.
- FIG. 28 is a schematic diagram for explaining the arrangement pattern (on-axis shift method) of the different refractive index regions n04-mb in the phase modulation layer n04-m.
- the phase modulation layer n04-m includes a basic region n04-ma having a first refractive index and a different refractive index region n04-mb having a second refractive index different from the first refractive index.
- a virtual square lattice defined on the XY plane is set in the phase modulation layer n04-m, as in the example of FIG.
- One side of the square lattice is parallel to the X axis, and the other side is parallel to the Y axis.
- the square unit constituting region R centering on the lattice point O of the square lattice extends over a plurality of columns (x1 to x4) along the X axis and a plurality of rows (y1 to y3) along the Y axis. Set in two dimensions. If the coordinates of each unit configuration region R are given by the centroid position of each unit configuration region R, the centroid position coincides with the lattice point O of a virtual square lattice.
- a plurality of different refractive index regions n04-mb is provided in each unit constituting region R.
- the planar shape of the different refractive index region n04-mb is, for example, a circular shape.
- the lattice point O may be located outside the different refractive index region n04-mb, or may be included inside the different refractive index region n04-mb.
- the ratio of the area S of the different refractive index regions n04-mb occupying in one unit constituent region R is called a filling factor (FF).
- FF filling factor
- S is the area of the different refractive index region n04-mb in the XY plane.
- S ⁇ (D / 2 ) Given as 2 .
- FIG. 29 illustrates, as an example of an arrangement pattern determined by the axis shift method, the positional relationship between the center of gravity G1 of the different refractive index region n04-mb and the lattice point O (x, y) in the virtual square lattice.
- FIG. 29 As shown in FIG. 29, the center of gravity G1 of each different refractive index region n04-mb is arranged on a straight line L.
- the straight line L is a straight line that passes through the corresponding lattice point O (x, y) of the unit configuration region R (x, y) and is inclined with respect to each side of the square lattice.
- the straight line L is a straight line that is inclined with respect to both the s axis and the t axis that define the unit configuration region R (x, y).
- the inclination angle of the straight line L with respect to the s-axis is ⁇ .
- the inclination angle ⁇ is constant in the phase modulation layer n04-m.
- the straight line L extends from the first quadrant to the third quadrant of the coordinate plane defined by the s axis and the t axis. .
- the straight line L extends from the second quadrant to the fourth quadrant of the coordinate plane defined by the s axis and the t axis.
- the inclination angle ⁇ is an angle excluding 0 °, 90 °, 180 °, and 270 °.
- the distance between the lattice point O (x, y) and the center of gravity G1 is r (x, y).
- x represents the position of the xth lattice point on the X axis
- y represents the position of the yth lattice point on the Y axis.
- the center of gravity G1 is located in the first quadrant (or the second quadrant).
- the center of gravity G1 is located in the third quadrant (or the fourth quadrant).
- the lattice point O and the center of gravity G1 coincide with each other.
- Each of the different refractive index regions n04-mb is individually set according to the target beam projection pattern (light image).
- the distribution of the distance r (x, y) has a specific value for each position determined by the values of x (x1 to x4 in the example of FIG. 28) and y (y1 to y3 in the example of FIG.
- the distribution of the distance r (x, y) is determined from the phase amplitude extracted from the complex amplitude distribution obtained by inverse Fourier transform of the target beam projection pattern. That is, when the phase P (x, y) in the unit configuration region R (x, y) shown in FIG. 29 is P 0 , the distance r (x, y) is set to 0, and the phase P ( The distance r (x, y) is set to the maximum value R 0 when x, y) is ⁇ + P 0 , and the distance r (x, y) when the phase P (x, y) is ⁇ + P 0. ) Is set to the minimum value -R 0 .
- the initial phase P 0 can be set arbitrarily.
- the maximum value R 0 of r (x, y) is, for example, in the range of the following formula (10).
- the reproducibility of the beam projection pattern is applied by applying an iterative algorithm such as the Gerchberg-Saxton (GS) method that is generally used when calculating the hologram generation. Will improve.
- FIG. 30 is a plan view showing an example in which a refractive index substantially periodic structure is applied only in a specific region of the phase modulation layer as a first modification of the phase modulation layer in FIG.
- a substantially periodic structure for example, the structure of FIG. 28 for emitting a target beam projection pattern inside the square inner region RIN.
- a true circular different refractive index region having a centroid position coincident with a lattice point position of a square lattice is arranged.
- window function noise high-frequency noise
- light leakage in the in-plane direction can be suppressed, and a reduction in threshold current can be expected.
- phase modulation layer n04-m is configured to satisfy the following conditions under the three preconditions and the fourth precondition defined by the above formulas (6) and (7).
- the corresponding different refractive index region n04-mb is arranged in the unit configuration region R (x, y) so as to satisfy the following relationship.
- the distance r (x, y) is set to 0 when the phase P (x, y) in the unit configuration region R (x, y) is P 0 , and the phase P (x, y) is ⁇ + P. When it is 0, it is set to the maximum value R 0 , and when the phase P (x, y) is ⁇ + P 0, it is set to the minimum value ⁇ R 0 .
- the target beam projection pattern is subjected to inverse Fourier transform, and the distribution of the distance r (x, y) according to the phase P (x, y) of the complex amplitude is obtained. It may be given to the rate region n04-mb.
- the phase P (x, y) and the distance r (x, y) may be proportional to each other.
- the far-field image after Fourier transformation of the laser beam has various shapes such as single or multiple spot shapes, circular shapes, linear shapes, character shapes, double annular shapes, or Laguerre Gaussian beam shapes. Can take. Since the beam direction can also be controlled, for example, a laser that performs high-speed scanning electrically by arraying each of a plurality of semiconductor light-emitting elements in the semiconductor light-emitting modules according to the various embodiments described above one-dimensionally or two-dimensionally. A processing machine can be realized. Since the beam projection pattern is represented by angle information in the far field, in the case of a bitmap image or the like where the target beam projection pattern is represented by two-dimensional position information, it is once converted into angle information. Then, it is preferable to perform inverse Fourier transform after conversion to wave number space.
- the intensity distribution I (x, y) is calculated by using the abs function of the numerical analysis software “MATLAB” of MathWorks.
- the phase distribution P (x, y) can be calculated by using an angle function of MATLAB.
- FIG. 31 is a diagram for explaining points to consider when determining the arrangement of the different refractive index regions by obtaining the phase angle distribution (corresponding to the rotation angle distribution in the rotation method) from the inverse Fourier transform result of the target beam projection pattern. .
- the beam projection pattern calculated from the complex amplitude distribution obtained by the inverse Fourier transform of FIG. 31A, which is the target beam projection pattern, is in the state shown in FIG.
- the first quadrant of the beam projection pattern in FIG. A superimposed pattern in which the pattern rotated by 180 degrees in the first quadrant of (a) and the pattern of the third quadrant of FIG.
- the second quadrant of FIG. 31B a superposed pattern in which the pattern rotated 180 degrees in the second quadrant of FIG. 31A and the pattern of the fourth quadrant of FIG.
- the third quadrant of FIG. 31B a superposed pattern in which the pattern rotated 180 degrees in the third quadrant of FIG. 31A and the pattern of the first quadrant of FIG.
- the first quadrant of the original optical image is added to the third quadrant of the obtained beam projection pattern.
- a pattern obtained by rotating the first quadrant of the original optical image by 180 degrees appears in the first quadrant of the obtained beam projection pattern.
- the material system, the film thickness, and the layer configuration can be variously changed as long as the configuration includes the active layer and the phase modulation layer.
- the scaling law holds for a so-called square lattice photonic crystal laser in which the perturbation from the virtual square lattice is zero. That is, when the wavelength becomes a constant ⁇ times, a similar standing wave state can be obtained by multiplying the entire square lattice structure by ⁇ times.
- the structure of the phase modulation layer n04-m can be determined by a scaling rule corresponding to the wavelength. Therefore, it is also possible to realize a semiconductor light emitting device that outputs visible light by using the active layer 12 that emits light of blue, green, red, and the like, and applying a scaling rule according to the wavelength.
- a resonance mode (standing wave in the XY plane) in which the grating interval a is equal to the wavelength ⁇ is obtained.
- oscillation in such a resonance mode (standing wave state) is obtained.
- the standing wave state having the same lattice spacing and wavelength has four modes due to the symmetry of the square lattice.
- a desired beam projection pattern can be obtained in the same manner even when oscillating in any of the four standing wave states.
- the standing wave in the phase modulation layer n04-m is scattered by the hole shape, and the wavefront obtained in the direction perpendicular to the plane is phase-modulated, whereby a desired beam projection pattern is obtained. Therefore, a desired beam projection pattern can be obtained without a polarizing plate.
- This beam projection pattern is not only a pair of unimodal beams (spots), but as described above, the character shape, two or more identically shaped spot groups, or the phase and intensity distribution are spatially non-uniform. It is also possible to use a vector beam or the like.
- the refractive index of the basic region n04-ma is preferably 3.0 to 3.5, and the refractive index of the different refractive index region n04-mb is preferably 1.0 to 3.4.
- the average radius of each of the different refractive index regions n04-mb in the hole of the basic region n04-ma is, for example, 20 nm to 120 nm in the case of the 940 nm band. As the size of each of the different refractive index regions n04-mb changes, the diffraction intensity in the Z-axis direction changes.
- This diffraction efficiency is proportional to the optical coupling coefficient ⁇ 1 represented by a first-order coefficient when the shape of the different refractive index region n04-mb is Fourier transformed.
- the optical coupling coefficient is described in Non-Patent Document 2, for example.
- the semiconductor light emitting device including the phase modulation layer n04-m in which the arrangement pattern of the different refractive index regions n04-mb is determined by the on-axis shift method as described above will be described.
- the center of gravity G1 of each of the different refractive index regions n04-mb is arranged away from the corresponding lattice point O of the virtual square lattice, and around the lattice points O according to the optical image.
- Those having a different rotation angle are known (see, for example, Patent Document 1).
- the phase modulation layer n04-m optically coupled to the active layer has a basic region n04-ma and a plurality of different refractive index regions n04-mb having a refractive index different from that of the basic region n04-ma.
- the center of gravity G1 of the refractive index region n04-mb is disposed.
- the distance r (x, y) between the center G1 of each of the different refractive index regions n04-mb and the corresponding lattice point O is individually set according to the target beam projection pattern.
- the beam phase changes according to the distance between the lattice point O and the center of gravity G1. That is, the phase of the beam emitted from each of the different refractive index regions n04-mb can be controlled only by changing the position of the center of gravity G1, and the beam projection pattern formed as a whole can have a desired shape (target beam projection). Pattern).
- each of the semiconductor light emitting elements described above is an S-iPM laser, and according to such a structure, the center of gravity G1 of each of the different refractive index regions n04-mb rotates around each lattice point O according to the target beam projection pattern.
- a beam projection pattern having an arbitrary shape can be output in a direction inclined with respect to a direction perpendicular to the first surface where anger is output.
- the on-axis shift method can provide a semiconductor light emitting device and a semiconductor light emitting module in which the positional relationship between the gravity center G1 of each different refractive index region n04-mb and each lattice point O is completely different from the conventional one.
- FIG. 32A is a diagram showing an example of a beam projection pattern (light image) output from the semiconductor light emitting element.
- the center of FIG. 32A corresponds to an axis that intersects the light emitting surface of the semiconductor light emitting element and is perpendicular to the light emitting surface.
- FIG. 32B is a graph showing a light intensity distribution in a cross section including an axis that intersects the light emitting surface of the semiconductor light emitting element and is perpendicular to the light emitting surface.
- FIG. 32B is a graph showing a light intensity distribution in a cross section including an axis that intersects the light emitting surface of the semiconductor light emitting element and is perpendicular to the light emitting surface.
- FIG. 32B is a far-field image 1344 acquired using an FFP optical system (A3267-12 manufactured by Hamamatsu Photonics), a camera (ORCA-05G manufactured by Hamamatsu Photonics), and a beam profiler (Lepas-12 manufactured by Hamamatsu Photonics).
- the counts in the vertical direction of dot ⁇ 1024 dot image data are integrated and plotted. Note that the maximum count number in FIG. 32A is normalized by 255, and the center zero-order light B0 is saturated in order to clearly indicate the intensity ratio of ⁇ first-order light. From FIG. 32 (b), the difference in intensity between the primary light and the negative primary light can be easily understood.
- FIG. 33A is a diagram showing a phase distribution corresponding to the beam projection pattern shown in FIG. FIG.
- 33 (b) is a partially enlarged view of FIG. 33 (a).
- 33 (a) and 33 (b) the phase at each location in the phase modulation layer n04-m is shown by shading, with the dark portion having a phase angle of 0 ° and the bright portion having a phase angle of 360 °. Get closer.
- the center value of the phase angle can be set arbitrarily, it is not always necessary to set the phase angle within the range of 0 ° to 360 °. As shown in FIG. 32A and FIG.
- the semiconductor light emitting element includes primary light including a first light image portion B1 output in a first direction inclined with respect to the axis, The first-order light is output in a second direction that is symmetric with respect to the first direction with respect to the axis, and includes the first light image portion B1 and the second light image portion B2 that is rotationally symmetric with respect to the axis.
- the first light image portion B1 appears in the first quadrant in the XY plane
- the second light image portion B2 appears in the third quadrant in the XY plane.
- only the primary light is used and the ⁇ 1st order light is not used. In such a case, it is desirable that the light amount of the ⁇ 1st order light be suppressed to be smaller than that of the primary light.
- FIG. 34 is a diagram conceptually showing an example of a beam projection pattern of traveling waves in each direction.
- the inclination angle of the straight line L with respect to the s-axis and the t-axis is 45 °.
- basic traveling waves AU, AD, AR, and AL are generated along the XY plane.
- Traveling waves AU and AD are light traveling along the side extending in the Y-axis direction among the sides of the square lattice.
- the traveling wave AU travels in the Y-axis positive direction
- the traveling wave AD travels in the Y-axis negative direction.
- the traveling waves AR and AL are light traveling along the sides extending in the X-axis direction among the sides of the square lattice.
- the traveling wave AR travels in the positive direction of the X axis
- the traveling wave AL travels in the negative direction of the X axis.
- beam projection patterns in opposite directions are obtained from traveling waves traveling in opposite directions.
- a beam projection pattern BU including only the second light image portion B2 is obtained from the traveling wave AU
- a beam projection pattern BD including only the first light image portion B1 is obtained from the traveling wave AD.
- a beam projection pattern BR including only the second light image portion B2 is obtained from the traveling wave AR
- a beam projection pattern BL including only the first light image portion B1 is obtained from the traveling wave AL.
- the beam projection pattern output from the semiconductor light emitting element is an overlap of these beam projection patterns BU, BD, BR, and BL.
- both traveling waves traveling in opposite directions are caused by the nature of the arrangement of the different refractive index region.
- the same amount of the first-order light and the ⁇ 1st-order light appears in any of the four traveling waves AU, AD, AR, and AL forming the standing wave, and the radius of the rotating circle ( Depending on the distance between the center of gravity of the different refractive index region and the lattice point, zero-order light is generated.
- FIG. 35 as a method for determining the arrangement pattern of the above-described different refractive index regions n04-mb, a rotation method in which the different refractive index regions are rotated around lattice points, and traveling waves AU, AD, AR, and AL are shown.
- FIG. 35 The reason why it is difficult to selectively reduce either the first-order light or the ⁇ 1st-order light in the rotation method in which the different refractive index region n04-mb is rotated around the lattice point O will be described.
- a traveling wave AU having a positive direction of the t-axis shown in FIG. 35B is considered.
- the phase distribution ⁇ (x, y) can be series-expanded, and the zero-order light And each light quantity of ⁇ primary light can be explained.
- the zero-order light component of the phase distribution ⁇ (x, y) is J 0 (2 ⁇ r / a)
- the first-order light component is J 1 (2 ⁇ r / a)
- the ⁇ 1st- order light component is J ⁇ 1 (2 ⁇ r / a). a).
- the Y-axis positive traveling wave AU is considered as an example of the four traveling waves, but the same relationship holds for the other three waves (traveling waves AD, AR, AL), and ⁇ 1st order light
- the component sizes are equal. From the above discussion, in the conventional method in which the different refractive index region n04-mb is rotated around the lattice point O, it is theoretically difficult to give a difference in the light amount of the ⁇ first-order light component.
- the phase modulation layer n04-m in which the arrangement pattern of the different refractive index regions n04-mb is determined by the axial shift method the primary light and the ⁇ 1st order are obtained for a single traveling wave.
- the shift amount R 0 becomes closer to the upper limit value of the above-described equation (9), so that the ideal Phase distribution can be obtained.
- the zero-order light is reduced, and one of the first-order light and the ⁇ 1st-order light is selectively reduced in each of the traveling waves AU, AD, AR, and AL. Therefore, in principle, it is possible to give a difference between the light amounts of the primary light and the ⁇ 1st order light by selectively reducing one of the traveling waves traveling in opposite directions.
- FIG. 36 shows a method of determining the arrangement pattern of the different refractive index regions n04-mb, an axial shift method in which the different refractive index regions are moved on an axis that passes through the lattice points and is inclined with respect to the square lattice, and a traveling wave AU, It is a figure which shows AD, AR, and AL.
- the center of gravity G1 of the different refractive index region n04-mb moves on a straight line L passing through the lattice point O and inclined with respect to both the s-axis and the t-axis defining the unit constituent region R, as shown in FIG.
- FIG. 36B shows an example of four traveling waves with respect to the design phase ⁇ (x, y) (corresponding to the rotation angle in FIG. 5 in the rotation method) in the unit configuration region R (x, y).
- the deviation from the lattice point O is r ⁇ sin ⁇ ⁇ ⁇ (x, y) ⁇ 0 ⁇ / ⁇ for the traveling wave AU, and the phase difference is ( 2 ⁇ / a) r ⁇ sin ⁇ ⁇ ⁇ (x, y) ⁇ 0 ⁇ / ⁇ .
- the phase distribution ⁇ (x, y) (corresponding to the above-described phase distribution P (x, y)) relating to the traveling wave AU is negligibly affected by the size of the different refractive index region n04-mb.
- the magnitude of the 0th-order light component of the phase distribution ⁇ (x, y) is It is represented by the following formula (15).
- size of the primary light component of phase distribution (PHI) (x, y) is represented by the following formula
- the magnitude of the ⁇ 1st order light component of the phase distribution ⁇ (x, y) is expressed by the following equation (17). In the above formulas (15) to (17), the 0th-order light component and the ⁇ 1st-order light component appear in addition to the primary light component except when the condition defined by the following formula (18) is satisfied. However, the magnitudes of the ⁇ first-order light components are not equal to each other.
- the traveling wave AU in the Y-axis positive direction is considered as an example of the four traveling waves, but the same relationship holds for the other three waves (traveling waves AD, AR, AL), and ⁇ 1 A difference occurs in the magnitude of the secondary light component.
- the axial shift method in which the different refractive index region n04-mb moves on the straight line L that passes through the lattice point O and is inclined from the square lattice, it is possible to give a difference in the light amount of the ⁇ first-order light components. It is possible in principle.
- first light image portion B1 or second light image portion B2 it is possible to selectively extract only a desired light image (first light image portion B1 or second light image portion B2) by reducing ⁇ 1st order light or primary light. Also in FIG. 32B described above, it can be seen that there is a difference in intensity between the primary light and the ⁇ 1st order light.
- the inclination angle ⁇ of the straight line L in the unit constituent region R may be constant in the phase modulation layer n04-m.
- the design of the arrangement of the center of gravity G1 of the different refractive index region n04-mb can be easily performed.
- the inclination angle may be 45 °, 135 °, 225 °, or 315 °.
- the inclination angle ⁇ is 0 °, 90 °, 180 °, or 270 °, of the four traveling waves AU, AD, AR, and AL, a pair of progressions proceeding in the Y-axis direction or the X-axis direction. Since the waves do not contribute to the primary light (signal light), it is difficult to increase the efficiency of the signal light.
- the shape of the different refractive index region n04-mb on the XY plane is circular.
- the different refractive index region n04-mb may have a shape other than a circle.
- the shape of the different refractive index region n04-mb may have mirror image symmetry (line symmetry).
- mirror image symmetry refers to the planar shape of the different refractive index region n04-mb located on one side of the straight line across a certain straight line along the XY plane, and the straight line.
- planar shape of the different refractive index region n04-mb located on the other side of each other can be mirror-image symmetric (line symmetric).
- line symmetry for example, a perfect circle shown in FIG. 37A, a square shown in FIG. 37B, a regular hexagon shown in FIG. 37C, The regular octagon shown in FIG. 37 (d), the regular hexagon shown in FIG. 37 (e), the rectangle shown in FIG. 37 (f), the ellipse shown in FIG. 37 (g), etc. Can be mentioned.
- each of the unit structure regions R of the virtual square lattice of the phase modulation layer n04-m Since the shape is simple, the direction and position of the center of gravity G1 of the corresponding refractive index region n04-mb from the lattice point O can be determined with high accuracy. That is, patterning with high accuracy is possible.
- the shape of the different refractive index region n04-mb on the XY plane may be a shape having no rotational symmetry of 180 °.
- Such shapes include, for example, an equilateral triangle shown in FIG. 38 (a), a right isosceles triangle shown in FIG. 38 (b), and a portion of two circles or ellipses shown in FIG. 38 (c).
- An oval shape shown in FIG. 38 (d) a teardrop shape shown in FIG. 38 (e), an isosceles triangle shown in FIG. 38 (f), and FIG. 38 (g).
- FIG. Examples include a shape in which a part of two rectangles shown in 38 (k) overlap with each other and has no mirror image symmetry.
- the oval shape is a shape deformed so that the dimension in the short axis direction near one end along the major axis of the ellipse is smaller than the dimension in the short axis direction near the other end.
- the teardrop shape is a shape in which one end portion along the major axis of the ellipse is deformed into a sharp end projecting along the major axis direction.
- the arrow-shaped shape is a shape in which one side of a rectangle is recessed in a triangular shape, and the opposite side is pointed in a triangular shape.
- the different refractive index region n04-mb may be composed of a plurality of elements as shown in FIGS. 38 (j) and 38 (k).
- the center of gravity of the different refractive index region n04-m G1 is a composite centroid of a plurality of components.
- FIG. 39 is a diagram showing still another example (on-axis shift method) of the planar shape of the different refractive index region.
- FIG. 40 is a diagram illustrating a second modification of the phase modulation layer of FIG.
- each of the different refractive index regions n04-mb includes a plurality of components 15b and 15c.
- the centroid G1 is a combined centroid of all the components and is located on the straight line L.
- Both the components 15b and 15c have a second refractive index different from the first refractive index of the basic region n04-ma.
- Both of the components 15b and 15c may be holes, or may be configured by embedding a compound semiconductor in the holes.
- the component 15c is provided in one-to-one correspondence with the component 15b.
- the center of gravity G1 obtained by combining the constituent elements 15b and 15c is located on a straight line L that crosses the lattice point O of the unit constituent region R that constitutes a virtual square lattice. Note that any of the constituent elements 15b and 15c is included within the range of the unit constituent region R that forms a virtual square lattice.
- the unit configuration area R is an area surrounded by a straight line that bisects the lattice points of a virtual square lattice.
- the planar shape of the component 15c is, for example, a circle, but can have various shapes as in the various examples shown in FIGS. 39 (a) to 39 (k) show examples of the shapes and relative relationships of the components 15b and 15c on the XY plane.
- FIG. 39A and FIG. 39B show a form in which both the components 15b and 15c have the same shape.
- FIG. 39 (c) and FIG. 39 (d) show a form in which both of the components 15b and 15c have the same shape and a part of each other overlaps.
- FIG. 39 (e) shows a form in which both the constituent elements 15b and 15c have the same shape, and the distance between the centroids of the constituent elements 15b and 15c is arbitrarily set for each lattice point.
- FIG. 39A and FIG. 39B show a form in which both the components 15b and 15c have the same shape.
- FIG. 39 (c) and FIG. 39 (d) show a form in which both of the components 15b and
- FIG. 39 (f) shows a form in which the components 15b and 15c have figures with different shapes.
- FIG. 39 (g) shows a form in which the constituent elements 15b and 15c have different shapes and the distance between the centroids of the constituent elements 15b and 15c is arbitrarily set for each lattice point.
- the component 15b constituting a part of the different refractive index region n04-mb is composed of two regions 15b1 and 15b2 spaced apart from each other. May be.
- the distance between the center of gravity of the regions 15b1 and 15b2 (corresponding to the center of gravity of the single component 15b) and the center of gravity of the component 15c may be arbitrarily set for each lattice point.
- the regions 15b1 and 15b2 and the component 15c may have figures having the same shape.
- two graphics in the regions 15b1 and 15b2 and the component 15c may be different from the others.
- the angle with respect to the s axis of the straight line connecting the regions 15b1 and 15b2 may be arbitrarily set for each lattice point. Good.
- the angle of the straight line connecting the regions 15b1 and 15b2 with respect to the s-axis is arbitrary for each lattice point while the regions 15b1 and 15b2 and the component 15c maintain the same relative angle. May be set.
- planar shape of the different refractive index regions n04-mb may be the same between the unit constituent regions R. That is, even if the different refractive index regions n04-mb have the same figure in all the unit configuration regions R, they can be overlapped with each other between the lattice points by translation operation or translation operation and rotation operation. Good. In that case, generation of noise light and zero-order light as noise in the beam projection pattern can be suppressed.
- the planar shape of the different refractive index regions n04-mb does not necessarily have to be the same between the unit constituent regions R. For example, as shown in FIG. 40, the shapes of the adjacent unit constituent regions R are different from each other. May be. As shown in the examples of FIGS. 36A and 36B, the center of the straight line L passing through each lattice point O matches the lattice point O in any case of FIGS. Is preferably set.
- the phase modulation layer in which the arrangement pattern of the different refractive index region is determined by the rotation method is applied even if the arrangement pattern of the different refractive index region is determined by the on-axis shift method.
- the same effects as those of the embodiment described above can be suitably achieved.
- second cladding layer 108-m, 208-m, 308-m, 108B-m ... second surface side Electrode, 110, 210, 310, 110B-m ... first surface side electrode, 112, 212, 312, 112B ... separation region.
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Abstract
Embodiments of the present invention pertain to a single semiconductor light-emitting element that has a plurality of light-emitting units each capable of generating light of a desired beam projection pattern, and a method for manufacturing the semiconductor light-emitting element. This semiconductor light-emitting element has an active layer and a phase modulation layer formed on a common substrate layer, and at least the phase modulation layer includes a plurality of phase modulation regions arranged along the common substrate layer. The phase modulation regions are obtained by separately arranging at a plurality of portions in the phase modulation layer after production of the phase modulation layer. Thus, provided is a semiconductor light-emitting element having light-emitting units that are accurately positioned through a production process simpler than conventional technology.
Description
本発明は、半導体発光素子およびその製造方法に関するものである。
The present invention relates to a semiconductor light emitting device and a method for manufacturing the same.
特許文献1に記載の半導体発光素子は、活性層と、活性層に光学的に結合した位相変調層と、を備えている。位相変調層は、基本層と、基本層内に配置されている複数の異屈折率領域と、を有している。特許文献1に記載の半導体発光素子は、複数の異屈折率領域の配置パターンに対応したビームパターン(ビーム投射パターン)の光を出射する。すなわち、複数の異屈折率領域の配置パターンは、目標ビームパターンに応じて設定される。特許文献1には、そのような半導体発光素子の応用例についても記載されている。上記応用例は、それぞれが出射するレーザビームの方向が異なる複数の半導体発光素子を支持基板上に一次元または二次元に配列したものである。そして、上記応用例は、配列した複数の半導体発光素子を順次点灯することで、レーザビームを対象物に対して走査するように構成されている。上記応用例は、レーザビームを対象物に対して走査することで、対象物までの距離測定、対象物のレーザ加工等に適用される。
The semiconductor light-emitting element described in Patent Document 1 includes an active layer and a phase modulation layer optically coupled to the active layer. The phase modulation layer has a base layer and a plurality of different refractive index regions arranged in the base layer. The semiconductor light emitting element described in Patent Document 1 emits light of a beam pattern (beam projection pattern) corresponding to the arrangement pattern of a plurality of different refractive index regions. That is, the arrangement pattern of the plurality of different refractive index regions is set according to the target beam pattern. Patent Document 1 also describes an application example of such a semiconductor light emitting element. In the above application example, a plurality of semiconductor light emitting elements each having a different direction of the emitted laser beam are arranged one-dimensionally or two-dimensionally on a support substrate. And the said application example is comprised so that a laser beam may be scanned with respect to a target object by lighting the arranged several semiconductor light-emitting element sequentially. The application example described above is applied to distance measurement to an object, laser processing of the object, and the like by scanning the object with a laser beam.
発明者らは、従来の半導体発光素子について検討した結果、以下のような課題を発見した。すなわち、特許文献1に記載された応用例では、複数の半導体発光素子を支持基板上に高精度に配置しなければならない。することは容易ではないため、所望のビーム投射領域への所望のビーム投射パターンの光の照射を高精度に実現することが容易ではなかった。また、複数の半導体発光素子を支持基板上に配置する工程が必要であるため、製造工程が複雑化するおそれもあった。
As a result of examining the conventional semiconductor light emitting device, the inventors have found the following problems. That is, in the application example described in Patent Document 1, a plurality of semiconductor light emitting elements must be arranged on the support substrate with high accuracy. Since it is not easy to do, it has not been easy to realize the irradiation of light of a desired beam projection pattern to a desired beam projection region with high accuracy. Moreover, since the process of arrange | positioning a several semiconductor light-emitting element on a support substrate is required, there also existed a possibility that a manufacturing process might become complicated.
本発明は、このような問題に鑑みてなされたものであり、複数の半導体発光素子を支持基板上に配置する工程が不要で、目標ビーム投射領域への目標ビーム投射パターンの光の照射が容易かつ高精度に実現された半導体発光素子およびその製造方法を提供することを目的としている。
The present invention has been made in view of such problems, and does not require a step of disposing a plurality of semiconductor light emitting elements on a support substrate, and makes it easy to irradiate a target beam projection area with light of a target beam projection pattern. It is another object of the present invention to provide a semiconductor light emitting device and a method for manufacturing the same that are realized with high accuracy.
本実施形態に係る半導体発光素子は、隣接する発光部間のクロストークが軽減された複数の発光部を有する単一の半導体発光素子であって、第1面と該第1面に対向する第2面とを有し、第1面および第2面の一方が光を出力する光出射面として機能するとともに他方がサポート面(反射面を含む)として機能する半導体発光素子であって、活性層と、複数の位相変調領域を含む位相変調層と、第1クラッド層と、第2クラッド層と、第1面側電極と、複数の第2面側電極と、共通基板層と、を備える。活性層は、第1面と第2面との間に位置する。位相変調層に含まれる複数の位相変調層は、活性層とそれぞれが光学的に結合される。複数の位相変調領域それぞれは、隣接する位相変調領域の間でのクロストークの発生が低減されるよう配置され、それぞれが独立した発光部の一部を構成する。また、複数の位相変調領域それぞれは、第1屈折率を有する基本領域と、それぞれが基本領域内に設けられるとともに第1屈折率とは異なる第2屈折率を有する複数の異屈折率領域とを含む。第1クラッド層は、少なくとも活性層および位相変調層を含む積層構造体に対して第1面が配置された側に位置する。第2クラッド層は、積層構造体に対して第2面が位置する側に配置される。第1面側電極は、第1クラッド層に対して第1面が位置する側に配置される。複数の第2面側電極は、複数の位相変調領域にそれぞれが対応しており、第2クラッド層に対して第2面が位置する側に配置される。これら複数の第2面側電極は、積層構造体の積層方向に沿って見たときに複数の位相変調領域と重なる複数の領域内にそれぞれ配置される。共通基板層は、第1クラッド層と第1面側電極との間に配置され、複数の位相変調領域を保持する連続した面を有する。
The semiconductor light-emitting device according to the present embodiment is a single semiconductor light-emitting device having a plurality of light-emitting portions in which crosstalk between adjacent light-emitting portions is reduced, and a first surface and a first surface facing the first surface. A semiconductor light emitting device having two surfaces, wherein one of the first surface and the second surface functions as a light emitting surface that outputs light, and the other functions as a support surface (including a reflective surface), and an active layer A phase modulation layer including a plurality of phase modulation regions, a first cladding layer, a second cladding layer, a first surface side electrode, a plurality of second surface side electrodes, and a common substrate layer. The active layer is located between the first surface and the second surface. The plurality of phase modulation layers included in the phase modulation layer are optically coupled to the active layer. Each of the plurality of phase modulation areas is arranged so as to reduce the occurrence of crosstalk between adjacent phase modulation areas, and each constitutes a part of an independent light emitting unit. Each of the plurality of phase modulation regions includes a basic region having a first refractive index, and a plurality of different refractive index regions each provided in the basic region and having a second refractive index different from the first refractive index. Including. The first cladding layer is located on the side where the first surface is disposed with respect to the multilayer structure including at least the active layer and the phase modulation layer. The second cladding layer is disposed on the side where the second surface is located with respect to the laminated structure. The first surface side electrode is disposed on the side where the first surface is located with respect to the first cladding layer. The plurality of second surface side electrodes respectively correspond to the plurality of phase modulation regions, and are disposed on the side where the second surface is located with respect to the second cladding layer. The plurality of second surface side electrodes are respectively disposed in a plurality of regions overlapping with the plurality of phase modulation regions when viewed along the stacking direction of the stacked structure. The common substrate layer is disposed between the first cladding layer and the first surface side electrode and has a continuous surface that holds a plurality of phase modulation regions.
特に、複数の位相変調領域それぞれにおける複数の異屈折率領域は、それぞれの重心が基本領域中の仮想的な正方格子における各格子点から所定の距離だけずれた場所に位置するような配置パターンに従って基本領域中に配置される。なお、複数の位相変調領域それぞれにおける配置パターン(複数の異屈折率領域の配置パターン)は、サポート面側に配置された、当該位相変調領域に対応する第2面側電極から駆動電流が供給されたときに光出射面から出力される光のビーム投射パターンと該ビーム投射パターンの投射範囲であるビーム投射領域が、目標ビーム投射パターンおよび目標ビーム投射領域に一致するよう定められている。
In particular, the plurality of different refractive index regions in each of the plurality of phase modulation regions are arranged in accordance with an arrangement pattern in which each center of gravity is located at a position that is shifted by a predetermined distance from each lattice point in a virtual square lattice in the basic region. Arranged in the base area. The arrangement pattern in each of the plurality of phase modulation regions (arrangement pattern of the plurality of different refractive index regions) is supplied with a drive current from the second surface side electrode arranged on the support surface side and corresponding to the phase modulation region. The beam projection pattern of the light output from the light exit surface and the beam projection area that is the projection range of the beam projection pattern are determined to coincide with the target beam projection pattern and the target beam projection area.
本実施形態に係る半導体発光素子の製造方法は、上述のような構造を備えた半導体発光素子を製造する。具体的に、当該製造方法は、共通基板層を形成する第1工程と、素子本体を共通基板層上に形成する第2工程と、素子本体内に分離領域を形成する第3工程と、を少なくとも備える。第2工程において、共通基板層上に形成される素子本体は、第3面と該第3面に対向するとともに共通基板層に対面する第4面を有する。また、素子本体は、第3面と第4面との間に配置された、活性層、位相変調層、第1クラッド層、および第2クラッド層を少なくとも含む。第2工程の終了時点において、位相変調層における基本領域は、複数の位相変調領域となるべき複数の部分(それぞれが複数の異屈折率領域を含む部分)が互いに所定距離だけ離間した状態で配置された単一層で構成される。第3工程において、素子本体内に形成される分離領域は、少なくとも複数の位相変調領域となるべき複数の部分を電気的に分離する。また、分離領域は、第3面から第4面に向かって、共通基板層に到達するまで形成される。
The method for manufacturing a semiconductor light emitting device according to this embodiment manufactures a semiconductor light emitting device having the above-described structure. Specifically, the manufacturing method includes a first step of forming a common substrate layer, a second step of forming an element body on the common substrate layer, and a third step of forming an isolation region in the element body. At least. In the second step, the element main body formed on the common substrate layer has a third surface and a fourth surface facing the third surface and facing the common substrate layer. The element body includes at least an active layer, a phase modulation layer, a first cladding layer, and a second cladding layer disposed between the third surface and the fourth surface. At the end of the second step, the basic region in the phase modulation layer is arranged in a state where a plurality of portions (each of which includes a plurality of different refractive index regions) to be a plurality of phase modulation regions are separated from each other by a predetermined distance. Composed of a single layer. In the third step, the separation region formed in the element body electrically separates at least a plurality of portions to be a plurality of phase modulation regions. The isolation region is formed from the third surface toward the fourth surface until reaching the common substrate layer.
本発明によれば、複数の半導体発光素子を支持基板上に配置する工程が不要で、目標ビーム投射領域への目標ビーム投射パターンの光の照射が容易かつ高精度に実現された半導体発光素子およびその製造方法を提供することができる。
According to the present invention, there is no need for a step of disposing a plurality of semiconductor light emitting elements on a support substrate, and the semiconductor light emitting element in which irradiation of light of a target beam projection pattern to a target beam projection region is realized easily and with high accuracy. A manufacturing method thereof can be provided.
[本願発明の実施形態の説明]
最初に本願発明の実施形態の内容をそれぞれ個別に列挙して説明する。 [Description of Embodiment of Present Invention]
First, the contents of the embodiments of the present invention will be listed and described individually.
最初に本願発明の実施形態の内容をそれぞれ個別に列挙して説明する。 [Description of Embodiment of Present Invention]
First, the contents of the embodiments of the present invention will be listed and described individually.
(1) 本実施形態に係る半導体発光素子は、その一態様として、隣接する発光部間のクロストークが軽減された複数の発光部を有する単一の半導体発光素子であって、第1面と該第1面に対向する第2面とを有し、第1面および第2面の一方が光を出力する光出射面として機能するとともに他方がサポート面(反射面を含む)として機能する半導体発光素子であって、活性層と、複数の位相変調領域を含む位相変調層と、第1クラッド層と、第2クラッド層と、第1面側電極と、複数の第2面側電極と、共通基板層と、を備える。活性層は、第1面と第2面との間に位置する。位相変調層に含まれる複数の位相変調層は、活性層とそれぞれが光学的に結合される。複数の位相変調領域それぞれは、隣接する位相変調領域の間でのクロストークの発生が低減されるよう配置され、それぞれが独立した発光部の一部を構成する。また、複数の位相変調領域それぞれは、第1屈折率を有する基本領域と、それぞれが基本領域内に設けられるとともに第1屈折率とは異なる第2屈折率を有する複数の異屈折率領域とを含む。第1クラッド層は、少なくとも活性層および位相変調層を含む積層構造体に対して第1面が配置された側に位置する。第2クラッド層は、積層構造体に対して第2面が位置する側に配置される。第1面側電極は、第1クラッド層に対して第1面が位置する側に配置される。複数の第2面側電極は、複数の位相変調領域にそれぞれが対応しており、第2クラッド層に対して第2面が位置する側に配置される。これら複数の第2面側電極は、積層構造体の積層方向に沿って見たときに複数の位相変調領域と重なる複数の領域内にそれぞれ配置される。共通基板層は、第1クラッド層と第1面側電極との間に配置され、複数の位相変調領域を保持する連続した面を有する。
(1) The semiconductor light-emitting device according to the present embodiment is a single semiconductor light-emitting device having a plurality of light-emitting portions in which crosstalk between adjacent light-emitting portions is reduced, as one aspect thereof, A semiconductor having a second surface facing the first surface, wherein one of the first surface and the second surface functions as a light emitting surface that outputs light, and the other functions as a support surface (including a reflective surface) A light-emitting element, an active layer, a phase modulation layer including a plurality of phase modulation regions, a first cladding layer, a second cladding layer, a first surface side electrode, and a plurality of second surface side electrodes, A common substrate layer. The active layer is located between the first surface and the second surface. The plurality of phase modulation layers included in the phase modulation layer are optically coupled to the active layer. Each of the plurality of phase modulation areas is arranged so as to reduce the occurrence of crosstalk between adjacent phase modulation areas, and each constitutes a part of an independent light emitting unit. Each of the plurality of phase modulation regions includes a basic region having a first refractive index, and a plurality of different refractive index regions each provided in the basic region and having a second refractive index different from the first refractive index. Including. The first cladding layer is located on the side where the first surface is disposed with respect to the multilayer structure including at least the active layer and the phase modulation layer. The second cladding layer is disposed on the side where the second surface is located with respect to the laminated structure. The first surface side electrode is disposed on the side where the first surface is located with respect to the first cladding layer. The plurality of second surface side electrodes respectively correspond to the plurality of phase modulation regions, and are disposed on the side where the second surface is located with respect to the second cladding layer. The plurality of second surface side electrodes are respectively disposed in a plurality of regions overlapping with the plurality of phase modulation regions when viewed along the stacking direction of the stacked structure. The common substrate layer is disposed between the first cladding layer and the first surface side electrode and has a continuous surface that holds a plurality of phase modulation regions.
さらに、複数の位相変調領域それぞれは、複数の異屈折率領域は、複数の第2面側電極のうち対応する第2面側電極から駆動電流が供給されたときに光出射面から出力される光のビーム投射パターンおよび該ビーム投射パターンの投射範囲であるビーム投射領域を、目標ビーム投射パターンおよび目標ビーム投射領域にそれぞれ一致させるための配置パターンに従って、基本領域中における所定位置に配置されている。
Further, each of the plurality of phase modulation regions is output from the light emitting surface when the driving current is supplied from the corresponding second surface side electrode among the plurality of second surface side electrodes. The light beam projection pattern and the beam projection area that is the projection range of the beam projection pattern are arranged at predetermined positions in the basic area according to the arrangement pattern for matching the target beam projection pattern and the target beam projection area, respectively. .
なお、第1前提条件として、光出射面の法線方向に一致するZ軸と、複数の異屈折率領域を含む位相変調層の一方の面に一致した、互いに直交するX軸およびY軸を含むX-Y平面と、により規定されるXYZ直交座標系において、X-Y平面上に、それぞれが正方形状を有するM1(1以上の整数)×N1(1以上の整数)個の単位構成領域Rにより構成される仮想的な正方格子が設定される。このとき、配置パターンは、X軸方向の座標成分x(1以上M1以下の整数)とY軸方向の座標成分y(1以上N1以下の整数)とで特定されるX-Y平面上の単位構成領域R(x,y)において、単位構成領域R(x,y)内に位置する異屈折率領域の重心G1が単位構成領域R(x,y)の中心となる格子点O(x,y)から距離rだけ離れ、かつ、格子点O(x,y)から前記重心G1へのベクトルが特定方向に向くよう、規定される。
As a first precondition, a Z axis that coincides with the normal direction of the light exit surface and an X axis and a Y axis that coincide with one surface of the phase modulation layer including a plurality of different refractive index regions are orthogonal to each other. In the XYZ Cartesian coordinate system defined by the XY plane, M1 (an integer of 1 or more) × N1 (an integer of 1 or more) unit constituent regions each having a square shape on the XY plane A virtual square lattice constituted by R is set. At this time, the arrangement pattern is a unit on the XY plane specified by a coordinate component x (an integer between 1 and M1) in the X-axis direction and a coordinate component y (an integer between 1 and N1) in the Y-axis direction. In the configuration region R (x, y), the lattice point O (x, y) where the centroid G1 of the different refractive index region located in the unit configuration region R (x, y) is the center of the unit configuration region R (x, y). It is defined that the vector from the grid point O (x, y) to the centroid G1 is directed in a specific direction, and is separated from the y) by a distance r.
(2)本実施形態に係る半導体発光素子の製造方法は、その一態様として、上述のような構造を備えた半導体発光素子を製造する。具体的に、当該製造方法は、共通基板層を形成する第1工程と、素子本体を共通基板層上に形成する第2工程と、素子本体内に分離領域を形成する第3工程と、を少なくとも備える。第2工程において、共通基板層上に形成される素子本体は、第3面と該第3面に対向するとともに共通基板層に対面する第4面を有する。また、素子本体は、第3面と第4面との間に配置された、活性層、位相変調層、第1クラッド層、および第2クラッド層を少なくとも含む。第2工程の終了時点において、位相変調層における基本領域は、複数の位相変調領域となるべき複数の部分(それぞれが複数の異屈折率領域を含む部分)が互いに所定距離だけ離間した状態で配置された単一層で構成される。第3工程において、素子本体内に形成される分離領域は、少なくとも複数の位相変調領域となるべき複数の部分を電気的に分離する。また、分離領域は、3面から第4面に向かって、共通基板層に到達するまで形成される。
(2) The semiconductor light-emitting device manufacturing method according to the present embodiment manufactures a semiconductor light-emitting device having the above-described structure as one aspect thereof. Specifically, the manufacturing method includes a first step of forming a common substrate layer, a second step of forming an element body on the common substrate layer, and a third step of forming an isolation region in the element body. At least. In the second step, the element main body formed on the common substrate layer has a third surface and a fourth surface facing the third surface and facing the common substrate layer. The element body includes at least an active layer, a phase modulation layer, a first cladding layer, and a second cladding layer disposed between the third surface and the fourth surface. At the end of the second step, the basic region in the phase modulation layer is arranged in a state where a plurality of portions (each of which includes a plurality of different refractive index regions) to be a plurality of phase modulation regions are separated from each other by a predetermined distance. Composed of a single layer. In the third step, the separation region formed in the element body electrically separates at least a plurality of portions to be a plurality of phase modulation regions. The separation region is formed from the third surface toward the fourth surface until reaching the common substrate layer.
本実施形態に係る半導体発光素子では、複数の位相変調領域それぞれにおける配置パターン(複数の異屈折率領域の配置パターン)は、当該位相変調領域に対応する第2面側電極から駆動電流が供給されたときに光出射面(第1面または第2面)から出力される光のビーム投射パターンおよび該ビーム投射パターンの投射範囲であるビーム投射領域が、目標ビーム投射パターンおよび目標ビーム投射領域に一致するとなるように定められている。したがって、複数の位相変調領域それぞれにおいて設定された配置パターンが、当該半導体発光素子の光出射面から出力される光のビーム投射領域とビーム投射パターンとを決定する。本実施形態では、1つの半導体発光素子が、光のビーム投射領域とビーム投射パターンとを決定する複数の位相変調領域を有する位相変調層を備えている。この構成により、本実施形態に係る製造方法では、それぞれ一つの位相変調領域(位相変調層)を備える複数の半導体発光素子が支持基板上に配置されている構成とは異なり、複数の半導体発光素子が支持基板上に配置される工程が不要になる。その結果、目標ビーム投射領域への目標ビーム投射パターンの光の照射が容易かつ高精度に実現され得る。
In the semiconductor light emitting device according to this embodiment, the arrangement pattern in each of the plurality of phase modulation regions (the arrangement pattern of the plurality of different refractive index regions) is supplied with a drive current from the second surface side electrode corresponding to the phase modulation region. The beam projection pattern of the light output from the light emission surface (first surface or second surface) and the beam projection area that is the projection range of the beam projection pattern coincide with the target beam projection pattern and the target beam projection area It is stipulated to be. Therefore, the arrangement pattern set in each of the plurality of phase modulation regions determines the beam projection region and the beam projection pattern of light output from the light emitting surface of the semiconductor light emitting element. In the present embodiment, one semiconductor light emitting element includes a phase modulation layer having a plurality of phase modulation areas for determining a light beam projection area and a beam projection pattern. With this configuration, in the manufacturing method according to this embodiment, unlike the configuration in which a plurality of semiconductor light emitting elements each having one phase modulation region (phase modulation layer) are arranged on a support substrate, a plurality of semiconductor light emitting elements Is not required to be disposed on the support substrate. As a result, irradiation of the light of the target beam projection pattern to the target beam projection region can be realized easily and with high accuracy.
(3)本実施形態の一態様として、当該半導体発光素子は、複数の位相変調領域それぞれを電気的に分離するとともに、Z軸に沿った方向(以下、「Z軸方向」という)から見たときに複数の位相変調領域と重なる、活性層、第1クラッド層、および第2クラッド層それぞれにおける複数の対応領域を電気的に分離する分離領域を更に備えてもよい。また、本実施形態の一態様として、分離領域は、複数の位相変調領域とともに、活性層、位相変調層、第1クラッド層、および第2クラッド層それぞれにおける複数の対応領域を光学的に分離してもよい。このように隣接する位相変調領域が分離領域によって電気的に分離されるので、隣接する位相変調領域間でのクロストークの発生が抑制される。また、隣接する位相変調領域が分離領域によって光学的にも分離されることにより、隣接する位相変調領域間でのクロストークの発生が更に抑制される。この結果、所望のビーム投射領域(目標ビーム投射領域)への所望のビーム投射パターン(目標ビーム投射パターン)の光の照射が、より一層高精度で実現される。
(3) As one aspect of the present embodiment, the semiconductor light emitting element electrically separates each of the plurality of phase modulation regions and is viewed from a direction along the Z axis (hereinafter referred to as “Z axis direction”). A separation region that electrically separates a plurality of corresponding regions in each of the active layer, the first cladding layer, and the second cladding layer, which sometimes overlaps the plurality of phase modulation regions, may be further provided. As one aspect of the present embodiment, the separation region optically separates a plurality of corresponding regions in each of the active layer, the phase modulation layer, the first cladding layer, and the second cladding layer together with the plurality of phase modulation regions. May be. As described above, the adjacent phase modulation regions are electrically separated by the separation region, so that occurrence of crosstalk between the adjacent phase modulation regions is suppressed. Further, since the adjacent phase modulation areas are optically separated by the separation areas, the occurrence of crosstalk between the adjacent phase modulation areas is further suppressed. As a result, irradiation of light of a desired beam projection pattern (target beam projection pattern) to a desired beam projection area (target beam projection area) is realized with higher accuracy.
(4)本実施形態の一態様として、分離領域は、複数の位相変調領域のうち隣接する位相変調領域の間の領域において、第2面から共通基板層面に向かって、該共通基板層に到達するまで伸びている。また、分離領域の先端と第1面側電極との距離(最短距離)は、共通基板層の、Z軸方向に沿った厚みの半分以下であるのが好ましい。典型的には、該分離領域の先端と第1面側電極との距離は70μm以下であるのが好ましい。この場合、隣接する位相変調領域間でのクロストークの発生が十分に抑制される。
(4) As one aspect of this embodiment, the separation region reaches the common substrate layer from the second surface toward the common substrate layer surface in a region between adjacent phase modulation regions among the plurality of phase modulation regions. It grows until you do. Moreover, it is preferable that the distance (shortest distance) between the tip of the separation region and the first surface side electrode is not more than half the thickness of the common substrate layer along the Z-axis direction. Typically, the distance between the tip of the separation region and the first surface side electrode is preferably 70 μm or less. In this case, the occurrence of crosstalk between adjacent phase modulation regions is sufficiently suppressed.
(5)本実施形態の一態様として、分離領域は、高強度光照射に起因した電場により改質された半導体層であってもよい。この場合、隣接する位相変調領域間が電気的に分離され、隣接する位相変調領域間でのクロストークの発生が十分に抑制された半導体発光素子が、効率的に製造され得る。また、分離領域は、不純物拡散またはイオン打ち込み法により絶縁化された半導体層、および、ドライエッチングまたはウェットエッチングにより形成された空気間隙(スリット)のうち何れかであってもよい。この場合、隣接する位相変調領域間が電気的にも光学的にも分離され、隣接する位相変調領域間でのクロストークの発生が十分に抑制された半導体発光素子が、効率的に製造され得る。
(5) As one aspect of the present embodiment, the separation region may be a semiconductor layer modified by an electric field resulting from high-intensity light irradiation. In this case, a semiconductor light emitting device in which adjacent phase modulation regions are electrically separated and generation of crosstalk between adjacent phase modulation regions is sufficiently suppressed can be efficiently manufactured. The isolation region may be any of a semiconductor layer insulated by impurity diffusion or ion implantation and an air gap (slit) formed by dry etching or wet etching. In this case, a semiconductor light emitting device in which adjacent phase modulation regions are electrically and optically separated, and occurrence of crosstalk between adjacent phase modulation regions is sufficiently suppressed can be efficiently manufactured. .
(6)本実施形態の一態様として、第2面側電極の何れかから駆動電流が供給された場合にもビーム投射領域が等しくなるように、位相変調領域それぞれにおける配置パターンが定められてもよい。この場合、特許文献1に示された半導体発光素子の応用例(レーザビームを対象物に対して走査するようにした応用例)以外への各種の応用が可能になる。例えば、スクリーンの同じ領域に複数のパターンを切替表示するタイプの各種表示装置への応用、一箇所に同じパターンの光を継続的あるいは断続的に照射するタイプの各種照明への応用、一箇所に同じパターンのパルス光を連続的に照射することで対象物に目標パターンの孔を穿設するタイプのレーザ加工への応用等が可能になる。
(6) As one aspect of the present embodiment, even if the arrangement pattern in each of the phase modulation areas is determined so that the beam projection areas are equal even when a drive current is supplied from any of the second surface side electrodes. Good. In this case, various applications other than the application example (application example in which the laser beam is scanned with respect to the object) of the semiconductor light emitting device disclosed in Patent Document 1 are possible. For example, application to various types of display devices that switch and display multiple patterns in the same area of the screen, application to various types of illumination that irradiate light of the same pattern continuously or intermittently at one location, By continuously irradiating pulsed light of the same pattern, it is possible to apply to laser processing of a type in which holes of a target pattern are formed in an object.
(7)本実施形態の一態様として、複数の第2面側電極の何れかから駆動電流が供給された場合にもビーム投射パターンが等しくなるように、位相変調領域それぞれにおける配置パターンが定められてもよい。この場合、特許文献1に示された半導体発光素子の応用例(レーザビームを対象物に対して走査するようにした応用例)と同様の応用が可能になる他、それとは異なる各種の応用も可能になる。特許文献1に示された応用例とは異なる応用としては、一箇所に同じパターンの光を継続的あるいは断続的に照射するタイプの各種照明への応用、一箇所に同じパターンのパルス光を連続的に照射することで対象物に目標パターンの孔を穿設するタイプのレーザ加工への応用等、上述の応用の他、任意の個所を適宜のタイミングで照射するタイプの照明等への応用も可能になる。
(7) As one aspect of the present embodiment, the arrangement pattern in each of the phase modulation regions is determined so that the beam projection patterns are equal even when a drive current is supplied from any of the plurality of second surface side electrodes. May be. In this case, an application similar to the application example of the semiconductor light emitting device disclosed in Patent Document 1 (application example in which the laser beam is scanned with respect to the object) is possible, and various other applications are also possible. It becomes possible. As an application different from the application example shown in Patent Document 1, it is applied to various types of illumination in which the same pattern light is continuously or intermittently applied to one place, and the same pattern pulse light is continuously applied to one place. In addition to the above-mentioned applications, such as the application to laser processing of the type that drills holes of the target pattern in the target by irradiating the target, it can also be applied to illumination of the type that irradiates any part at an appropriate timing It becomes possible.
上述のような構造を有する半導体発光素子においては、活性層に光学的に結合した位相変調層が、基本層と、それぞれが基本層内に埋め込まれるとともに、該基本層の屈折率とは異なる屈折率をそれぞれが有する複数の異屈折率領域とを有する。また、仮想的な正方格子を構成する単位構成領域R(x,y)において、対応する異屈折率領域の重心G1が格子点O(x,y)から離れて配置される。更に、格子点Oから重心G1へのベクトルの向きが単位構成領域Rごとに個別に設定されている。このような構成において、格子点Oから対応する異屈折率領域の重心G1へのベクトルの向き、すなわち該異屈折率領域の重心G1の格子点周りの角度位置に応じて、ビームの位相が変化する。このように、本実施形態によれば、異屈折率領域の重心位置を変更するのみで、異屈折率領域それぞれから出力されるビームの位相を制御することができ、全体として形成されるビーム投射パターン(光像を形成するビーム群)を所望の形状に制御することができる。このとき、仮想的な正方格子における格子点は異屈折率領域の外部に位置していてもよく、また、該格子点が異屈折率領域の内部に位置していてもよい。
In the semiconductor light emitting device having the structure as described above, the phase modulation layer optically coupled to the active layer is embedded in the basic layer and the refractive index different from the refractive index of the basic layer. A plurality of different refractive index regions each having a refractive index. Further, in the unit configuration region R (x, y) constituting the virtual square lattice, the centroid G1 of the corresponding different refractive index region is arranged away from the lattice point O (x, y). Furthermore, the direction of the vector from the lattice point O to the center of gravity G1 is individually set for each unit configuration region R. In such a configuration, the phase of the beam changes depending on the direction of the vector from the lattice point O to the centroid G1 of the corresponding refractive index region, that is, the angular position around the lattice point of the centroid G1 of the different refractive index region. To do. Thus, according to the present embodiment, the phase of the beam output from each of the different refractive index regions can be controlled only by changing the position of the center of gravity of the different refractive index region, and the beam projection formed as a whole The pattern (a group of beams forming an optical image) can be controlled to a desired shape. At this time, the lattice point in the virtual square lattice may be located outside the different refractive index region, or the lattice point may be located inside the different refractive index region.
(8)本実施形態の一態様として、仮想的な正方格子の格子定数(実質的に格子間隔に相当)をaとするとき、単位構成領域R(x,y)内に位置する異屈折率領域の重心G1と、格子点O(x,y)との距離rは、0≦r≦0.3aを満たすのが好ましい。また、複数の位相変調領域それぞれに対応して半導体発光素子から出射される光のビーム投射パターンとなる元の画像(二次元逆フーリエ変換前の光像)としては、例えば、スポット、3点以上からなるスポット群、直線、十字架、線画、格子パターン、縞状パターン、図形、写真、コンピュータグラフィクス、および文字のうち少なくとも1つを含むのが好ましい。
(8) As one aspect of the present embodiment, when the lattice constant (substantially equivalent to the lattice spacing) of a virtual square lattice is a, the different refractive index located in the unit constituent region R (x, y) The distance r between the center of gravity G1 of the region and the lattice point O (x, y) preferably satisfies 0 ≦ r ≦ 0.3a. In addition, as an original image (light image before two-dimensional inverse Fourier transform) serving as a beam projection pattern of light emitted from a semiconductor light emitting element corresponding to each of a plurality of phase modulation regions, for example, a spot, three or more points It preferably includes at least one of a spot group consisting of: a straight line, a cross, a line drawing, a lattice pattern, a striped pattern, a figure, a photograph, computer graphics, and characters.
(9) 本実施形態の一態様では、第1前提条件の他、第2前提条件として、XYZ直交座標系における座標(x,y,z)は、図41に示されたように、動径の長さd1と、Z軸からの傾き角θtiltと、X-Y平面上で特定されるX軸からの回転角θrotと、で規定される球面座標(d1,θtilt,θrot)に対して、以下の式(1)~式(3)で示された関係を満たしているものとする。なお、図41は、球面座標(d1,θtilt,θrot)からXYZ直交座標系における座標(x,y,z)への座標変換を説明するための図であり、座標(x,y,z)により、実空間であるXYZ直交座標系において設定される所定平面(目標ビーム投射領域)上の設計上の光像が表現される。半導体発光素子から出力される光像に相当する目標ビーム投射パターンを角度θtiltおよびθrotで規定される方向に向かう輝点の集合とするとき、角度θtiltおよびθrotは、以下の式(4)で規定される規格化波数であってX軸に対応したKx軸上の座標値kxと、以下の式(5)で規定される規格化波数であってY軸に対応するとともにKx軸に直交するKy軸上の座標値kyに換算されるものとする。規格化波数は、仮想的な正方格子の格子間隔に相当する波数を1.0として規格化された波数を意味する。このとき、Kx軸およびKy軸により規定される波数空間において、光像に相当するビーム投射パターンを含む特定の波数範囲が、それぞれが正方形状のM2(1以上の整数)×N2(1以上の整数)個の画像領域FRで構成される。なお、整数M2は、整数M1と一致する必要はない。同様に、整数N2は、整数N1と一致する必要もない。また、式(4)および式(5)は、例えば、上記非特許文献1に開示されている。
(9) In one aspect of the present embodiment, as the second precondition in addition to the first precondition, the coordinates (x, y, z) in the XYZ orthogonal coordinate system are as shown in FIG. Spherical coordinates (d1, θ tilt , θ rot ) defined by the length d1 of the lens , the tilt angle θ tilt from the Z axis, and the rotation angle θ rot from the X axis specified on the XY plane On the other hand, it is assumed that the relationships expressed by the following equations (1) to (3) are satisfied. FIG. 41 is a diagram for explaining coordinate conversion from spherical coordinates (d1, θ tilt , θ rot ) to coordinates (x, y, z) in the XYZ orthogonal coordinate system. z) represents a design optical image on a predetermined plane (target beam projection region) set in the XYZ orthogonal coordinate system which is a real space. When a set of bright points towards the target beam projection pattern corresponding to a light image emitted by the semiconductor light emitting device in the direction defined by the angle theta tilt and theta rot, the angle theta tilt and theta rot has the following formula ( 4) the normalized wave number defined by 4) and corresponding to the coordinate value k x on the Kx axis corresponding to the X axis, and the normalized wave number defined by the following equation (5) corresponding to the Y axis and Kx shall be converted into coordinate values k y on Ky axis perpendicular to the axis. The normalized wave number means a wave number normalized with 1.0 as the wave number corresponding to the lattice spacing of a virtual square lattice. At this time, in the wave number space defined by the Kx axis and the Ky axis, specific wave number ranges including the beam projection pattern corresponding to the optical image are each M2 (an integer of 1 or more) × N2 (an integer of 1 or more) It is composed of (integer) image areas FR. Note that the integer M2 need not match the integer M1. Similarly, the integer N2 need not match the integer N1. Moreover, Formula (4) and Formula (5) are disclosed by the said nonpatent literature 1, for example.
第3前提条件として、波数空間において、Kx軸方向の座標成分kx(1以上M2以下の整数)とKy軸方向の座標成分ky(1以上N2以下の整数)とで特定される画像領域FR(kx,ky)それぞれを、X軸方向の座標成分x(1以上M1以下の整数)とY軸方向の座標成分y(1以上N1以下の整数)とで特定されるX-Y平面上の単位構成領域R(x,y)に二次元逆フーリエ変換することで得られる複素振幅F(x,y)が、jを虚数単位として、以下の式(6)で与えられる。また、この複素振幅F(x,y)は、振幅項をA(x,y)とするとともに位相項をP(x,y)とするとき、以下の式(7)により規定される。更に、第4前提条件として、単位構成領域R(x,y)が、X軸およびY軸にそれぞれ平行であって単位構成領域R(x,y)の中心となる格子点O(x,y)において直交するs軸およびt軸で規定される。
As a third precondition, in the wave number space, an image area specified by a coordinate component k x (an integer of 1 to M2) in the Kx axis direction and a coordinate component k y (an integer of 1 to N2) in the Ky axis direction Each of FR (k x, k y ) is identified by an X-axis coordinate component x (an integer of 1 to M1) and a Y-axis coordinate component y (an integer of 1 to N1). The complex amplitude F (x, y) obtained by performing the two-dimensional inverse Fourier transform on the unit configuration region R (x, y) on the plane is given by the following formula (6), where j is an imaginary unit. The complex amplitude F (x, y) is defined by the following equation (7), where the amplitude term is A (x, y) and the phase term is P (x, y). Further, as a fourth precondition, the unit configuration region R (x, y) is parallel to the X axis and the Y axis, and is a lattice point O (x, y) that is the center of the unit configuration region R (x, y). ) In the orthogonal s axis and t axis.
上記第1~第4前提条件の下、位相変調層における異屈折率領域の配置パターンは、回転方式または軸上シフト方式により決定される。具体的に、回転方式による配置パターンの決定では、単位構成領域R(x,y)内において、格子点O(x,y)と対応する異屈折率領域の重心G1とを結ぶ線分と、s軸と、の成す角度φ(x,y)が、
φ(x,y)=C×P(x,y)+B
C:比例定数であって例えば180°/π
B:任意の定数であって例えば0
なる関係を満たすように、該対応する異屈折率領域が配置される。 Under the first to fourth preconditions, the arrangement pattern of the different refractive index regions in the phase modulation layer is determined by the rotation method or the on-axis shift method. Specifically, in the determination of the arrangement pattern by the rotation method, in the unit configuration region R (x, y), a line segment connecting the lattice point O (x, y) and the centroid G1 of the corresponding refractive index region, The angle φ (x, y) formed by the s axis is
φ (x, y) = C × P (x, y) + B
C: proportional constant, for example 180 ° / π
B: Arbitrary constant, for example 0
The corresponding different refractive index regions are arranged so as to satisfy the following relationship.
φ(x,y)=C×P(x,y)+B
C:比例定数であって例えば180°/π
B:任意の定数であって例えば0
なる関係を満たすように、該対応する異屈折率領域が配置される。 Under the first to fourth preconditions, the arrangement pattern of the different refractive index regions in the phase modulation layer is determined by the rotation method or the on-axis shift method. Specifically, in the determination of the arrangement pattern by the rotation method, in the unit configuration region R (x, y), a line segment connecting the lattice point O (x, y) and the centroid G1 of the corresponding refractive index region, The angle φ (x, y) formed by the s axis is
φ (x, y) = C × P (x, y) + B
C: proportional constant, for example 180 ° / π
B: Arbitrary constant, for example 0
The corresponding different refractive index regions are arranged so as to satisfy the following relationship.
上述のような構造を有する半導体発光素子では、位相変調層において、仮想的な正方格子を構成する各単位構成領域の中心(格子点)と、対応する異屈折率領域の重心G1との距離rは、位相変調層全体に亘って一定値であることが好ましい(なお、部分的に距離rが異なっていることは排除されない)。これにより、位相変調層全体における位相分布(単位構成領域R(x,y)に割り当てられた複素振幅F(x,y)における位相項P(x,y)の分布)が0~2π(rad)まで等しく分布している場合、平均すると、異屈折率領域の重心は正方格子における単位構成領域Rの格子点に一致することとなる。したがって、上記の位相変調層における二次元分布ブラッグ回折効果は、正方格子の各格子点上に異屈折率領域が配置された場合の二次元分布ブラッグ回折効果に近づくこととなるので、定在波の形成が容易となり、発振のための閾値電流低減を期待できる。
In the semiconductor light emitting device having the above-described structure, in the phase modulation layer, the distance r between the center (lattice point) of each unit constituting region constituting the virtual square lattice and the centroid G1 of the corresponding different refractive index region. Is preferably a constant value over the entire phase modulation layer (note that it is not excluded that the distance r is partially different). As a result, the phase distribution in the entire phase modulation layer (the distribution of the phase term P (x, y) in the complex amplitude F (x, y) assigned to the unit configuration region R (x, y)) is 0 to 2π (rad ), The center of gravity of the different refractive index region coincides with the lattice point of the unit constituent region R in the square lattice. Therefore, the two-dimensional distributed Bragg diffraction effect in the above phase modulation layer is close to the two-dimensional distributed Bragg diffraction effect when the different refractive index region is arranged on each lattice point of the square lattice. Can be easily formed, and a reduction in threshold current for oscillation can be expected.
(10)一方、軸上シフト方式による配置パターンの決定では、上記第1~第4前提条件の下、単位構成領域R(x,y)において、格子点O(x,y)を通る、s軸から傾斜した直線上に対応する異屈折率領域の重心G1が配置される。その際、格子点O(x,y)と該対応する異屈折率領域の重心G1までの線分長r(x,y)が、
r(x,y)=C×(P(x,y)-P0)
C:比例定数
P0:任意定数であって例えば0
なる関係を満たすように、該対応する異屈折率領域が単位構成領域R(x,y)内に配置される。なお、位相変調層における異屈折率領域の配置パターンが軸上シフト方式により決定された場合でも、上述の回転方式と同様の効果を奏する。 (10) On the other hand, in the determination of the arrangement pattern by the on-axis shift method, the unit configuration region R (x, y) passes through the lattice point O (x, y) under the first to fourth preconditions. The center of gravity G1 of the different refractive index region corresponding to the straight line inclined from the axis is arranged. At that time, the line segment length r (x, y) from the lattice point O (x, y) to the centroid G1 of the corresponding different refractive index region is
r (x, y) = C × (P (x, y) −P 0 )
C: Proportional constant P 0 : Arbitrary constant, for example 0
The corresponding different refractive index regions are arranged in the unit configuration region R (x, y) so as to satisfy the following relationship. Even when the arrangement pattern of the different refractive index regions in the phase modulation layer is determined by the on-axis shift method, the same effect as the above rotation method is obtained.
r(x,y)=C×(P(x,y)-P0)
C:比例定数
P0:任意定数であって例えば0
なる関係を満たすように、該対応する異屈折率領域が単位構成領域R(x,y)内に配置される。なお、位相変調層における異屈折率領域の配置パターンが軸上シフト方式により決定された場合でも、上述の回転方式と同様の効果を奏する。 (10) On the other hand, in the determination of the arrangement pattern by the on-axis shift method, the unit configuration region R (x, y) passes through the lattice point O (x, y) under the first to fourth preconditions. The center of gravity G1 of the different refractive index region corresponding to the straight line inclined from the axis is arranged. At that time, the line segment length r (x, y) from the lattice point O (x, y) to the centroid G1 of the corresponding different refractive index region is
r (x, y) = C × (P (x, y) −P 0 )
C: Proportional constant P 0 : Arbitrary constant, for example 0
The corresponding different refractive index regions are arranged in the unit configuration region R (x, y) so as to satisfy the following relationship. Even when the arrangement pattern of the different refractive index regions in the phase modulation layer is determined by the on-axis shift method, the same effect as the above rotation method is obtained.
(11)本実施形態の一態様として、複数の位相変調領域のうち少なくとも1つの位相変調領域において、複数の異屈折率領域の全ては、X-Y平面上で規定される形状、X-Y平面上で規定される面積、およびX-Y平面上で規定される距離rのうち少なくとも何れかが一致しているのが好ましい。ここで、上述の「X-Y平面上で規定される形状」には、1つの異屈折率領域を構成する複数要素の組合せ形状も含む(図25(h)~図25(k)参照)。これによれば、ビーム投射領域内におけるノイズ光およびノイズとなる0次光の発生を抑制することができる。なお、0次光とは、Z軸方向に平行に出力される光であり、位相変調層において位相変調されない光を意味する。
(11) As an aspect of the present embodiment, in at least one phase modulation region of the plurality of phase modulation regions, all of the plurality of different refractive index regions have a shape defined on the XY plane, XY It is preferable that at least one of the area defined on the plane and the distance r defined on the XY plane coincide with each other. Here, the above-mentioned “shape defined on the XY plane” includes a combined shape of a plurality of elements constituting one different refractive index region (see FIGS. 25 (h) to 25 (k)). . According to this, generation of noise light and zero-order light that becomes noise in the beam projection region can be suppressed. The zero-order light is light output in parallel with the Z-axis direction, and means light that is not phase-modulated in the phase modulation layer.
(12)本実施形態の一態様として、複数の異屈折率領域の、X-Y平面上における形状は、真円、正方形、正六角形、正八角形、正16角形、正三角形、直角二等辺三角形、長方形、楕円、2つの円または楕円の一部分が重なる形状、卵型形状、涙型形状、二等辺三角形、矢印型形状、台形、5角形、および、2つの矩形の一部分が重なる形状のうち何れかであるのが好ましい。なお、卵型形状は、図22(h)および図38(d)に示されたように、その長軸に沿った一方の端部近傍の短軸方向の寸法が、他方の端部近傍の該短軸方向の寸法よりも小さくなるように楕円を変形することにより得られる形状である。涙型形状は、図22(d)および図38(e)に示されたように、その長軸に沿った楕円の一方の端部を、長軸方向に沿って突き出る尖った端部に変形することにより得られる形状である。矢印型形状は、図22(e)および図38(g)に示されたように、矩形の一辺が三角形の切欠き部を構成する一方、該一辺に対向する辺が三角形の突起部を構成したな形状である。
(12) As one aspect of the present embodiment, the shape of the plurality of different refractive index regions on the XY plane is a perfect circle, square, regular hexagon, regular octagon, regular hexagon, regular triangle, right isosceles triangle , A rectangle, an ellipse, a shape in which two circles or a portion of an ellipse overlap, an oval shape, a teardrop shape, an isosceles triangle, an arrow shape, a trapezoid, a pentagon, and a shape in which two rectangles overlap It is preferable. In addition, as shown in FIG. 22 (h) and FIG. 38 (d), the oval shape has a dimension in the short axis direction near one end portion along the long axis thereof, which is near the other end portion. It is a shape obtained by deforming an ellipse so as to be smaller than the dimension in the minor axis direction. As shown in FIGS. 22 (d) and 38 (e), the teardrop shape deforms one end of an ellipse along its long axis into a sharp end protruding along the long axis. It is a shape obtained by doing. In the arrow shape, as shown in FIGS. 22E and 38G, one side of the rectangle forms a triangular cutout, and the side opposite to the one side forms a triangular protrusion. It is a shape.
複数の異屈折率領域の、X-Y平面上における形状が、真円、正方形、正六角形、正八角形、正16角形、長方形、および楕円の何れかの場合、すなわち、各異屈折率領域の形状が鏡像対称(線対称)となる場合、位相変調層において、仮想的な正方格子を構成する複数の単位構成領域Rそれぞれの格子点Oから、対応するそれぞれの異屈折率領域の重心G1へ向かう方向と、X軸に平行なs軸との成す角度φを高精度に設定することが可能になる。また、複数の異屈折率領域の、X-Y平面上における形状が、正三角形、直角二等辺三角形、二等辺三角形、2つの円または楕円の一部分が重なる形状、卵型形状、涙型形状、矢印型形状、台形、5角形、2つの矩形の一部分が重なる形状の何れかの場合、すなわち、180°の回転対称性を備えない場合、より高い光出力を得ることが可能になる。
When the shape of the plurality of different refractive index regions on the XY plane is any of a perfect circle, a square, a regular hexagon, a regular octagon, a regular hexagon, a rectangle, and an ellipse, that is, When the shape is mirror-image symmetric (line symmetric), in the phase modulation layer, from the lattice point O of each of the plurality of unit constituting regions R constituting the virtual square lattice, to the centroid G1 of the corresponding different refractive index region. It is possible to set the angle φ formed by the direction in which the heading direction and the s-axis parallel to the X-axis with high accuracy. In addition, the shape of the plurality of different refractive index regions on the XY plane is a regular triangle, a right isosceles triangle, an isosceles triangle, a shape in which two circles or a part of an ellipse overlap, an egg shape, a teardrop shape, In the case of any one of an arrow shape, a trapezoid, a pentagon, and a shape in which a part of two rectangles overlap each other, that is, when a rotational symmetry of 180 ° is not provided, higher light output can be obtained.
(13)本実施形態の一態様として、複数の位相変調領域のうち少なくとも1つの位相変調領域は、M1×N1個の単位構成領域Rで構成された内側領域と、該内側領域の外周を取り囲むように設けられた外側領域と、を有してもよい。なお、外側領域は、仮想的な正方格子と同一の格子構造を該仮想的な正方格子の外周に設定することにより規定される拡張正方格子における格子点とそれぞれが重なるよう配置された複数の周辺格子点異屈折率領域を含む。この場合、X-Y平面に沿った光漏れが抑制され、発振閾値電流を低減することが可能になる。
(13) As an aspect of the present embodiment, at least one phase modulation region among the plurality of phase modulation regions surrounds an inner region composed of M1 × N1 unit configuration regions R and an outer periphery of the inner region. And an outer region provided as described above. The outer region has a plurality of peripherals arranged so as to overlap with lattice points in the extended square lattice defined by setting the same lattice structure as the virtual square lattice on the outer periphery of the virtual square lattice. Includes a lattice point refractive index region. In this case, light leakage along the XY plane is suppressed, and the oscillation threshold current can be reduced.
(14)本実施形態の一態様として、複数の位相変調領域のうち少なくとも1つの位相変調領域は、複数の異屈折率領域とは異なる複数の別の異屈折率領域、すなわち、複数の格子点異屈折率領域を備えてもよい。複数の異屈折率領域は、M1×N1個の単位構成領域Rにそれぞれ配置されており、それぞれの重心G2が対応する単位構成領域Rの格子点Oに一致するよう配置されている。この場合、異屈折率領域と格子点異屈折率領域とで構成される組み合わせ形状が全体として180°の回転対称性を備えなくなる。そのため、より高い光出力が得られる。
(14) As an aspect of the present embodiment, at least one phase modulation region among the plurality of phase modulation regions includes a plurality of different refractive index regions different from the plurality of different refractive index regions, that is, a plurality of lattice points. A different refractive index region may be provided. The plurality of different refractive index regions are respectively arranged in M1 × N1 unit configuration regions R, and are arranged so that the respective centroids G2 coincide with the lattice points O of the corresponding unit configuration regions R. In this case, the combined shape composed of the different refractive index region and the lattice point different refractive index region does not have a rotational symmetry of 180 ° as a whole. Therefore, higher light output can be obtained.
以上、この[本願発明の実施形態の説明]の欄に列挙された各態様は、残りの全ての態様のそれぞれに対して、または、これら残りの態様の全ての組み合わせに対して適用可能である。
As described above, each aspect listed in this [Description of Embodiments of the Invention] is applicable to each of all the remaining aspects or to all combinations of these remaining aspects. .
[本願発明の実施形態の詳細]
以下、本実施形態に係る半導体発光素子およびその製造方法の具体的な構造を、添付図面を参照しながら詳細に説明する。なお、本発明はこれらの例示に限定されるものではなく、請求の範囲によって示され、請求の範囲と均等の意味および範囲内での全ての変更が含まれることが意図される。また、図面の説明において同一の要素には同一符号を付して重複する説明を省略する。 [Details of the embodiment of the present invention]
Hereinafter, the specific structure of the semiconductor light emitting device and the manufacturing method thereof according to the present embodiment will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited to these illustrations, is shown by the claim, and it is intended that all the changes within the meaning and range equivalent to a claim are included. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.
以下、本実施形態に係る半導体発光素子およびその製造方法の具体的な構造を、添付図面を参照しながら詳細に説明する。なお、本発明はこれらの例示に限定されるものではなく、請求の範囲によって示され、請求の範囲と均等の意味および範囲内での全ての変更が含まれることが意図される。また、図面の説明において同一の要素には同一符号を付して重複する説明を省略する。 [Details of the embodiment of the present invention]
Hereinafter, the specific structure of the semiconductor light emitting device and the manufacturing method thereof according to the present embodiment will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited to these illustrations, is shown by the claim, and it is intended that all the changes within the meaning and range equivalent to a claim are included. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.
(第1実施形態)
図1~図3を参照して、第1実施形態に係る半導体発光素子100の構成を説明する。図1は、第1実施形態に係る半導体発光素子100を第1面側から見た図である。図2は、半導体発光素子100を第2面側から見た図、図3は、図1、図2のIII-III線に沿っての断面図である。 (First embodiment)
The configuration of the semiconductorlight emitting device 100 according to the first embodiment will be described with reference to FIGS. FIG. 1 is a view of the semiconductor light emitting device 100 according to the first embodiment as viewed from the first surface side. 2 is a view of the semiconductor light emitting device 100 as viewed from the second surface side, and FIG. 3 is a cross-sectional view taken along line III-III in FIGS.
図1~図3を参照して、第1実施形態に係る半導体発光素子100の構成を説明する。図1は、第1実施形態に係る半導体発光素子100を第1面側から見た図である。図2は、半導体発光素子100を第2面側から見た図、図3は、図1、図2のIII-III線に沿っての断面図である。 (First embodiment)
The configuration of the semiconductor
図1~図3に示されたように、半導体発光素子100は、第1面100aと第2面100bとを有し、光出射面として第1面100aから光を出力する。なお、本実施形態では、第2面100bはサポート面として機能する。半導体発光素子100は、共通基板層101と、活性層103と、位相変調層104と、第1クラッド層102と、第2クラッド層106と、一対の第2面側電極108-1、108-2と、第1面側電極110と、を備える。位相変調層104は、活性層103と光学的に結合される一対の位相変調領域104-1、104-2を有する。なお、少なくとも、活性層103と一対の位相変調領域104-1、104-2を含む位相変調層104により積層構造体が構成されている。後述の実施形態においても積層構造体の構成は同様である。第1クラッド層102は、積層構造体(少なくとも、活性層103と位相変調層104を含む)に対して第1面100a側に位置する。第2クラッド層106は、積層構造体(少なくとも、活性層103と位相変調層104を含む)に対して第2面100b側に位置する。第2面側電極108-1、108-2は、第2クラッド層106に対して第2面100bが配置された側であって、位相変調領域104-1、104-2それぞれに対応する位置に配置されている。第1面側電極110は、第1クラッド層102に対して第1面100aが配置された側に位置する。
As shown in FIGS. 1 to 3, the semiconductor light emitting device 100 has a first surface 100a and a second surface 100b, and outputs light from the first surface 100a as a light emitting surface. In the present embodiment, the second surface 100b functions as a support surface. The semiconductor light emitting device 100 includes a common substrate layer 101, an active layer 103, a phase modulation layer 104, a first cladding layer 102, a second cladding layer 106, and a pair of second surface side electrodes 108-1, 108-. 2 and the first surface side electrode 110. The phase modulation layer 104 has a pair of phase modulation regions 104-1 and 104-2 that are optically coupled to the active layer 103. Note that a laminated structure is configured by at least the phase modulation layer 104 including the active layer 103 and the pair of phase modulation regions 104-1 and 104-2. The configuration of the laminated structure is the same in the embodiments described later. The first cladding layer 102 is located on the first surface 100a side with respect to the stacked structure (including at least the active layer 103 and the phase modulation layer 104). The second cladding layer 106 is located on the second surface 100b side with respect to the stacked structure (including at least the active layer 103 and the phase modulation layer 104). The second surface side electrodes 108-1 and 108-2 are on the side where the second surface 100b is disposed with respect to the second cladding layer 106, and positions corresponding to the phase modulation regions 104-1 and 104-2, respectively. Is arranged. The first surface side electrode 110 is located on the side where the first surface 100 a is disposed with respect to the first cladding layer 102.
位相変調領域104-1、104-2は、それぞれ、第1屈折率を有する基本領域104-1a、104-2aと、第1屈折率とは異なる第2屈折率を有する複数の異屈折率領域104-1b、104-2bを含む。複数の異屈折率領域104-1b、104-2bは、それぞれの重心G1が基本領域104-1a、104-2a中の仮想的な正方格子における各格子点から所定の距離rだけずれた場所に位置するような配置パターンに従って、基本領域104-1a、104-2a中に配置される。位相変調領域104-1、104-2それぞれにおいて、複数の異屈折率領域104-1bの配置パターンは、当該位相変調領域104-1または104-2に対応する第2面側電極108-1または108-2から駆動電流が供給されたときに第1面100aから出力される光で表現されるビーム投射パターンと該ビーム投射パターンの投射範囲であるビーム投射領域が、目標ビーム投射パターンと目標ビーム投射領域に一致するよう設定されている。
The phase modulation regions 104-1 and 104-2 include basic regions 104-1a and 104-2a having a first refractive index, and a plurality of different refractive index regions having a second refractive index different from the first refractive index, respectively. 104-1b and 104-2b. The plurality of different refractive index regions 104-1b and 104-2b are located at locations where the respective centroids G1 are shifted by a predetermined distance r from each lattice point in the virtual square lattice in the basic regions 104-1a and 104-2a. They are arranged in the basic areas 104-1a and 104-2a in accordance with the arrangement pattern. In each of the phase modulation regions 104-1 and 104-2, the arrangement pattern of the plurality of different refractive index regions 104-1b is the second surface side electrode 108-1 corresponding to the phase modulation region 104-1 or 104-2. The beam projection pattern expressed by the light output from the first surface 100a when the drive current is supplied from 108-2 and the beam projection area which is the projection range of the beam projection pattern are the target beam projection pattern and the target beam. It is set to match the projection area.
第2面側電極108-1から駆動電流が供給されたときに出力される光のビーム投射領域と、第2面側電極108-2から駆動電流が供給されたときに出力される光のビーム投射領域とは、同じであってもよいし異なっていてもよい。また、第2面側電極108-1から駆動電流が供給されたときに出力される光のビーム投射パターンと、第2面側電極108-2から駆動電流が供給されたときに出力されるビーム投射パターンも、同じであってもよいし異なっていてもよい。
A beam projection region of light output when a driving current is supplied from the second surface side electrode 108-1, and a light beam output when a driving current is supplied from the second surface side electrode 108-2. The projection area may be the same or different. Further, a beam projection pattern of light output when a driving current is supplied from the second surface side electrode 108-1, and a beam output when a driving current is supplied from the second surface side electrode 108-2. The projection pattern may be the same or different.
なお、本明細書でいう「ビーム投射領域」は1つの第2面側電極から駆動電流が供給されたときに半導体発光素子の第1面または第2面から出力される光の投射範囲を指し、「ビーム投射パターン」は、上記投射範囲内における光の投射パターン(光の強弱のパターン)を指す。
The “beam projection region” in this specification refers to a projection range of light output from the first surface or the second surface of the semiconductor light emitting element when a driving current is supplied from one second surface side electrode. “Beam projection pattern” refers to a light projection pattern (light intensity pattern) within the projection range.
活性層103、位相変調層104、第1クラッド層102、第2クラッド層106、および共通基板層101には、第2面100bから共通基板層101に向かって、該共通基板層101に到達するまで延びた分離領域112が設けられている。分離領域112は、Z軸方向(積層方向)から見たときに位相変調領域104-1、104-2と重なる、活性層103、第1クラッド層102、第2クラッド層106、第1クラッド層102、および第2クラッド層106それぞれにおける対応領域間を電気的および光学的に分離するよう、第2面100bから共通基板層101に向かって伸びている。共通基板層101のうち、分離領域112の下側に位置する部分の厚さ(分離領域112の第1面側電極110側の端面112aと第1面側電極110の間の最短距離)は、共通基板層101の厚さの半分以下であり、典型的には70μm以下である。図3に示されたように、分離領域112の位置で区切られる半導体発光素子100の各部分は、それぞれ独立した発光部(第1発光部、第2発光部)と看做すことができる。
The active layer 103, the phase modulation layer 104, the first cladding layer 102, the second cladding layer 106, and the common substrate layer 101 reach the common substrate layer 101 from the second surface 100b toward the common substrate layer 101. A separation region 112 is provided that extends to the end. The separation region 112 overlaps with the phase modulation regions 104-1 and 104-2 when viewed from the Z-axis direction (stacking direction), the active layer 103, the first cladding layer 102, the second cladding layer 106, and the first cladding layer. 102 and the second cladding layer 106 respectively extend from the second surface 100b toward the common substrate layer 101 so as to electrically and optically separate corresponding regions. The thickness of the portion of the common substrate layer 101 located below the separation region 112 (the shortest distance between the end surface 112a on the first surface side electrode 110 side of the separation region 112 and the first surface side electrode 110) is: The thickness is less than half of the thickness of the common substrate layer 101, and typically less than 70 μm. As shown in FIG. 3, each part of the semiconductor light emitting device 100 divided by the position of the isolation region 112 can be regarded as an independent light emitting part (first light emitting part, second light emitting part).
第1面側電極110は、図1および図3に示されたように、位相変調領域104-1、104-2と第2面側電極108-1、108-2に対応する位置に開口部110-1、110-2を有している。第1面側電極110は、開口部を有する電極の代わりに、透明電極であってもよい。
As shown in FIGS. 1 and 3, the first surface side electrode 110 has openings at positions corresponding to the phase modulation regions 104-1 and 104-2 and the second surface side electrodes 108-1 and 108-2. 110-1 and 110-2. The first surface side electrode 110 may be a transparent electrode instead of the electrode having the opening.
活性層103と位相変調層104の上下関係は、図3に示された上下関係と逆であってもよい。また、図3には、共通基板層101、上部光ガイド層105b、下部光ガイド層105a、コンタクト層107、絶縁層109、反射防止層111も記載されているが、半導体発光素子100は、必ずしもこれらを備えている必要はない。
The vertical relationship between the active layer 103 and the phase modulation layer 104 may be opposite to the vertical relationship shown in FIG. FIG. 3 also shows the common substrate layer 101, the upper light guide layer 105b, the lower light guide layer 105a, the contact layer 107, the insulating layer 109, and the antireflection layer 111. It is not necessary to have these.
これまでに説明した各層、各領域の構成材料、形状、寸法、分離領域の製造工程を除く主要工程を含む製造方法等は、特許文献1の記載内容に基づいて当業者が適宜選択可能であるが、以下にその一部の例を示す。すなわち、図3に示された各層の材料ないし構造の一例は、次のとおりである。共通基板層101はGaAsからなる。第1クラッド層102はAlGaAsからなる。活性層103は多重量子井戸構造MQW(障壁層:AlGaAs/井戸層:InGaAs)を有する。位相変調層104は、基本領域104-1a、104-2aと、基本領域104-1a、104-2a内に埋め込まれた複数の異屈折率領域104-1b、104-2bを含む。基本領域104-1a、104-2aはGaAsからなる。複数の異屈折率領域104-1b、104-2bがAlGaAsからなる。上部光ガイド層105bおよび下部光ガイド層105aはAlGaAsからなる。第2クラッド層106はAlGaAsからなる。コンタクト層107はGaAsからなる。絶縁層109はSiO2またはシリコン窒化物からなる。反射防止層111は、窒化シリコン(SiN)、二酸化シリコン(SiO2)などの誘電体単層膜或いは誘電体多層膜からなる。
A person skilled in the art can appropriately select the manufacturing method including the main processes excluding the manufacturing process of each layer and each region described above, the constituent material, the shape, the dimensions, and the separation region. However, some examples are shown below. That is, an example of the material or structure of each layer shown in FIG. 3 is as follows. The common substrate layer 101 is made of GaAs. The first cladding layer 102 is made of AlGaAs. The active layer 103 has a multiple quantum well structure MQW (barrier layer: AlGaAs / well layer: InGaAs). The phase modulation layer 104 includes basic regions 104-1a and 104-2a and a plurality of different refractive index regions 104-1b and 104-2b embedded in the basic regions 104-1a and 104-2a. The basic regions 104-1a and 104-2a are made of GaAs. The plurality of different refractive index regions 104-1b and 104-2b are made of AlGaAs. The upper light guide layer 105b and the lower light guide layer 105a are made of AlGaAs. The second cladding layer 106 is made of AlGaAs. The contact layer 107 is made of GaAs. The insulating layer 109 is made of SiO 2 or silicon nitride. The antireflection layer 111 is made of a dielectric single layer film or a dielectric multilayer film such as silicon nitride (SiN) or silicon dioxide (SiO 2 ).
本実施形態に係る製造方法では、共通基板の形成(第1工程)の後、上述のように共通基板層101上に素子本体(少なくとも、活性層103、位相変調層104、第1クラッド層102、第2クラッド層106を含む)が形成される(第2工程)。以上のように形成された素子本体に対し、第2面100bから共通基板層101に向かって、該共通基板層101に到達するまで伸びる分離領域112が形成される(第3工程)。分離領域112は、高強度光(電場)により改質された半導体層、不純物拡散およびイオン打ち込み法の何れかにより絶縁化された半導体層、または、ドライエッチングおよびウェットエッチングの何れかにより形成されたスリット(空隙)である。ここで、高強度光(電場)による改質の具体的手法としては、例えば、ナノ秒レーザによる加工や超短パルスレーザによる加工がある。複数の異屈折率領域104-1b、104-2bは、アルゴン、窒素または空気等が封入された空孔であってもよい。第2面100bから共通基板層101に向かって伸びる分離領域112は、共通基板層101を貫通する必要はない。ただし、Z軸方向に沿った共通基板層101の厚みのうち分離領域112が形成された部分の厚み(分離領域112の第1面側電極110側の端面112aと第1面側電極110の間の最短距離)は、発光部間のクロストークを低減するため、共通基板層101の厚みの半分以下であるのが好ましい。典型的には、分離領域112の未形成部分の厚みは70μm以下である。なお、本実施形態に係る製造方法は、後述の第2~第4実施形態に係る半導体発光素子の製造にも適用可能である。
In the manufacturing method according to this embodiment, after the formation of the common substrate (first step), the element body (at least the active layer 103, the phase modulation layer 104, and the first cladding layer 102) is formed on the common substrate layer 101 as described above. , Including the second cladding layer 106) (second step). An isolation region 112 extending from the second surface 100b toward the common substrate layer 101 until reaching the common substrate layer 101 is formed on the element body formed as described above (third step). The isolation region 112 is formed by a semiconductor layer modified by high-intensity light (electric field), a semiconductor layer insulated by any of impurity diffusion and ion implantation, or any of dry etching and wet etching It is a slit (gap). Here, as a specific method of modification by high intensity light (electric field), there are, for example, processing by a nanosecond laser and processing by an ultrashort pulse laser. The plurality of different refractive index regions 104-1b and 104-2b may be holes filled with argon, nitrogen, air, or the like. The separation region 112 extending from the second surface 100 b toward the common substrate layer 101 does not need to penetrate the common substrate layer 101. However, the thickness of the portion where the separation region 112 is formed in the thickness of the common substrate layer 101 along the Z-axis direction (between the end surface 112a on the first surface side electrode 110 side of the separation region 112 and the first surface side electrode 110). The shortest distance is preferably less than or equal to half the thickness of the common substrate layer 101 in order to reduce crosstalk between the light emitting portions. Typically, the thickness of the unformed portion of the separation region 112 is 70 μm or less. Note that the manufacturing method according to the present embodiment is also applicable to the manufacture of semiconductor light emitting devices according to second to fourth embodiments described later.
一例では、共通基板層101と第1クラッド層102には、N型の不純物が添加されている。第2クラッド層106とコンタクト層107には、P型の不純物が添加されている。また、第1クラッド層102と第2クラッド層106のエネルギーバンドギャップは、上部光ガイド層105bと下部光ガイド層105aのエネルギーバンドギャップよりも大きい。上部光ガイド層105bと下部光ガイド層105aのエネルギーバンドギャップは、活性層103の多重量子井戸構造MQWのエネルギーバンドギャップよりも大きく設定されている。
In one example, the common substrate layer 101 and the first cladding layer 102 are doped with N-type impurities. P-type impurities are added to the second cladding layer 106 and the contact layer 107. The energy band gap between the first cladding layer 102 and the second cladding layer 106 is larger than the energy band gap between the upper light guide layer 105b and the lower light guide layer 105a. The energy band gap between the upper light guide layer 105 b and the lower light guide layer 105 a is set to be larger than the energy band gap of the multiple quantum well structure MQW of the active layer 103.
次に、図4および図5を参照して、各位相変調領域における複数の異屈折率領域の配置パターンについて説明する。図4は、位相変調領域における異屈折率領域の配置パターンを説明するための模式図である。図5は、異屈折率領域の重心G1と仮想的な正方格子における格子点Oとの位置関係を説明するための図である。図4には、異屈折率領域は12個しか示されていないが、実際には、多数の異屈折率領域が設けられる。一例では704×704の異屈折率領域が設けられる。なお、ここで説明する配置パターンは、第1実施形態に特有の配置パターンではなく、後述の第2~第4実施形態の配置パターンも同様ある。そのため、図4では、位相変調領域、基本領域、複数の異屈折率領域それぞれを表す符号を一般化し、位相変調領域をn04-m、基本領域をn04-ma、複数の異屈折率領域をn04-mbで表している。なお、「n」は実施形態を区別するための番号(第1実施形態は「1」、第2実施形態は「2」、…)、mは1つの半導体発光モジュールを構成する半導体発光素子を区別するための番号であり、「n」および「m」とも、1以上の整数で表される。
Next, an arrangement pattern of a plurality of different refractive index regions in each phase modulation region will be described with reference to FIGS. FIG. 4 is a schematic diagram for explaining an arrangement pattern of the different refractive index regions in the phase modulation region. FIG. 5 is a diagram for explaining the positional relationship between the gravity center G1 of the different refractive index region and the lattice point O in the virtual square lattice. Although only twelve different refractive index regions are shown in FIG. 4, a large number of different refractive index regions are actually provided. In one example, a 704 × 704 different refractive index region is provided. The arrangement pattern described here is not an arrangement pattern specific to the first embodiment, and the arrangement patterns of the second to fourth embodiments described later are also the same. Therefore, in FIG. 4, the signs representing the phase modulation region, the basic region, and the plurality of different refractive index regions are generalized, the phase modulation region is n04-m, the basic region is n04-ma, and the plurality of different refractive index regions are n04. It is represented by -mb. In addition, “n” is a number for distinguishing the embodiments (the first embodiment is “1”, the second embodiment is “2”,...), And m is a semiconductor light emitting element constituting one semiconductor light emitting module. It is a number for distinguishing, and “n” and “m” are both represented by an integer of 1 or more.
図4に示されたように、位相変調層n04-mは、第1屈折率の基本領域n04-maと、第1屈折率とは異なる第2屈折率の異屈折率領域n04-mbとを含み、位相変調層n04-mに、X―Y平面上で規定される仮想的な正方格子が設定される。図4は、位相変調層における異屈折率領域の配置パターン(回転方式)を説明するための模式図である。正方格子の一辺はX軸と平行であり、他辺はY軸と平行である。このとき、正方格子の格子点Oを中心とする正方形状の単位構成領域Rが、X軸に沿った複数列およびY軸に沿った複数行にわたって二次元的に設定され得る。複数の異屈折率領域n04-mbは、各単位構成領域R内に1つずつ設けられる。異屈折率領域n04-mbの平面形状は、例えば円形状である。各単位構成領域R内において、異屈折率領域n04-mbの重心G1は、これに最も近い格子点Oから離れて配置される。具体的には、X-Y平面は、図3に示された半導体発光素子100-1、100-2それぞれの厚さ方向(Z軸)に直交する平面であって、異屈折率領域n04-mbを含む位相変調層n04-mの一方の面に一致している。正方格子を構成する単位構成領域Rそれぞれは、X軸方向の座標成分x(1以上の整数)とY軸方向の座標成分y(1以上の整数)とで特定され、単位構成領域R(x,y)として表される。このとき、単位構成領域R(x,y)の中心、すなわち格子点はO(x,y)で表される。なお、格子点Oは、異屈折率領域n04-mbの外部に位置しても良いし、異屈折率領域n04-mbの内部に含まれていても良い。なお、1つの単位構成領域R内に占める異屈折率領域n04-mbの面積Sの比率は、フィリングファクタ(FF)と称される。正方格子の格子間隔をaとすると、異屈折率領域n04-mbのフィリングファクタFFはS/a2として与えられる。SはX-Y平面における異屈折率領域n04-mbの面積であり、異屈折率領域n04-mの形状が例えば真円の場合、真円の直径Dを用いてS=π(D/2)2として与えられる。また、異屈折率領域n04-mbの形状が正方形の場合、正方形の一辺の長さLAを用いてS=LA2として与えられる。
As shown in FIG. 4, the phase modulation layer n04-m includes a first refractive index basic region n04-ma and a second refractive index different refractive index region n04-mb different from the first refractive index. In addition, a virtual square lattice defined on the XY plane is set in the phase modulation layer n04-m. FIG. 4 is a schematic diagram for explaining an arrangement pattern (rotation method) of different refractive index regions in the phase modulation layer. One side of the square lattice is parallel to the X axis, and the other side is parallel to the Y axis. At this time, the square unit constituting region R centering on the lattice point O of the square lattice can be set two-dimensionally over a plurality of columns along the X axis and a plurality of rows along the Y axis. A plurality of different refractive index regions n04-mb is provided in each unit constituting region R. The planar shape of the different refractive index region n04-mb is, for example, a circular shape. Within each unit constituent region R, the center of gravity G1 of the different refractive index region n04-mb is arranged away from the lattice point O closest to it. Specifically, the XY plane is a plane orthogonal to the thickness direction (Z axis) of each of the semiconductor light emitting devices 100-1 and 100-2 shown in FIG. This coincides with one surface of the phase modulation layer n04-m including mb. Each unit constituting region R constituting the square lattice is specified by a coordinate component x (an integer of 1 or more) in the X-axis direction and a coordinate component y (an integer of 1 or more) in the Y-axis direction, and the unit constituting region R (x , Y). At this time, the center of the unit configuration region R (x, y), that is, the lattice point is represented by O (x, y). The lattice point O may be located outside the different refractive index region n04-mb, or may be included inside the different refractive index region n04-mb. The ratio of the area S of the different refractive index regions n04-mb occupying in one unit constituent region R is called a filling factor (FF). When the lattice spacing of the square lattice is a, the filling factor FF of the different refractive index region n04-mb is given as S / a 2 . S is the area of the different refractive index region n04-mb in the XY plane. When the shape of the different refractive index region n04-m is, for example, a perfect circle, the diameter D of the perfect circle is used, and S = π (D / 2 ) Given as 2 . When the shape of the different refractive index region n04-mb is a square, S = LA 2 is given using the length LA of one side of the square.
図4において、x1~x4で示された破線は単位構成領域RにおけるX軸方向の中心位置を示し、y1~y3で示された破線は単位構成領域RにおけるY軸方向の中心位置を示す。したがって、破線x1~x4と破線y1~y3の各交点は、単位構成領域R(1,1)~R(3,4)それぞれの中心O(1,1)~O(3,4)、すなわち、格子点を示す。この仮想的な正方格子は格子定数はaである。なお、格子定数aは、発光波長に応じて調整される。
4, the broken lines indicated by x1 to x4 indicate the center position in the X-axis direction in the unit constituent area R, and the broken lines indicated by y1 to y3 indicate the center position in the Y-axis direction in the unit constituent area R. Accordingly, the intersections of the broken lines x1 to x4 and the broken lines y1 to y3 are the centers O (1,1) to O (3,4) of the unit constituent regions R (1,1) to R (3,4), that is, , Indicate lattice points. This virtual square lattice has a lattice constant of a. The lattice constant a is adjusted according to the emission wavelength.
上記異屈折率領域n04-mbの配置パターンは、目標ビーム投射領域と目標ビーム投射パターンに応じて、特許文献1に説明されている方法によって定められる。すなわち、各異屈折率領域n04-mbの重心G1を基本領域n04-ma中の仮想的な正方格子における各格子点(破線x1~x4と破線y1~y3の交点)からずらす方向を、目標ビーム投射領域と目標ビーム投射パターンに対応する元パターンを逆フーリエ変換して得られた位相に応じて決定することで、上記配置パターンが決定される。各格子点からずらす距離r(図5参照)は、特許文献1に記載されるように、正方格子の格子定数をaとしたときに0<r≦0.3aの範囲とすることが望ましい。各格子点からずらす距離rは、全ての位相変調領域、全ての異屈折率領域に渡って同一とされるのが通常であるが、一部の位相変調領域における距離rを他の位相変調領域における距離rと異なる値としてもよいし、一部の異屈折率領域の距離rを他の異屈折率領域の距離rと異なる値としてもよい。なお、図5は、回転方式により決定される配置パターン(回転方式)の一例を説明するための図であり、図5中には、単位構成領域R(x,y)の構成が示されており、格子点から異屈折率領域n04-mbまでの距離rは、r(x,y)で示されている。
The arrangement pattern of the different refractive index region n04-mb is determined by the method described in Patent Document 1 according to the target beam projection region and the target beam projection pattern. That is, the direction in which the center of gravity G1 of each different refractive index region n04-mb is shifted from each lattice point (intersection of broken lines x1 to x4 and broken lines y1 to y3) in a virtual square lattice in the basic region n04-ma The arrangement pattern is determined by determining the original pattern corresponding to the projection area and the target beam projection pattern according to the phase obtained by inverse Fourier transform. The distance r (see FIG. 5) shifted from each lattice point is preferably in the range of 0 <r ≦ 0.3a when the lattice constant of the square lattice is a, as described in Patent Document 1. The distance r shifted from each lattice point is usually the same over all phase modulation regions and all different refractive index regions, but the distance r in a part of the phase modulation regions is different from other phase modulation regions. The distance r of the different refractive index regions may be different from the distance r of the other different refractive index regions. FIG. 5 is a diagram for explaining an example of an arrangement pattern (rotation method) determined by the rotation method. FIG. 5 shows the configuration of the unit configuration region R (x, y). The distance r from the lattice point to the different refractive index region n04-mb is indicated by r (x, y).
図5に示されたように、正方格子を構成する単位構成領域R(x,y)は、格子点O(x,y)において互いに直交するs軸およびt軸によって規定される。なお、s軸はX軸に平行な軸であり、図4中に示された破線x1~x4に対応する。t軸はY軸に平行な軸であり、図4中に示された破線y1~y3に対応している。このように単位構成領域R(x,y)を規定するs-t平面において、格子点O(x,y)から重心G1に向かう方向とs軸との成す角度がφ(x,y)で与えられる。回転角度φ(x,y)が0°である場合、格子点O(x,y)と重心G1とを結ぶベクトルの方向はs軸の正方向と一致する。また、格子点O(x,y)と重心G1とを結ぶベクトルの長さ(距離rに相当)がr(x,y)で与えられる。
As shown in FIG. 5, the unit constituting region R (x, y) constituting the square lattice is defined by the s axis and the t axis that are orthogonal to each other at the lattice point O (x, y). The s-axis is an axis parallel to the X-axis, and corresponds to the broken lines x1 to x4 shown in FIG. The t-axis is an axis parallel to the Y-axis and corresponds to the broken lines y1 to y3 shown in FIG. Thus, in the st plane that defines the unit configuration region R (x, y), the angle formed between the direction from the lattice point O (x, y) toward the center of gravity G1 and the s axis is φ (x, y). Given. When the rotation angle φ (x, y) is 0 °, the direction of the vector connecting the lattice point O (x, y) and the center of gravity G1 coincides with the positive direction of the s axis. Further, the length of the vector connecting the lattice point O (x, y) and the center of gravity G1 (corresponding to the distance r) is given by r (x, y).
図4に示されたように、位相変調層n04-mにおいては、異屈折率領域n04-mbの重心G1の格子点O(x,y)周りの回転角度φ(x,y)が、目標ビーム投射パターン(光像)に応じて単位構成領域Rごとに独立して設定される。回転角度φ(x,y)は、単位構成領域R(x,y)において特定の値を有するが、必ずしも特定の関数で表わされるとは限らない。すなわち、回転角度φ(x,y)は、目標ビーム投射パターンを波数空間上に変換し、この波数空間の一定の波数範囲を二次元逆フーリエ変換して得られる複素振幅の位相項から決定される。なお、目標ビーム投射パターンから複素振幅分布(単位構成領域Rそれぞれの複素振幅)を求める際には、ホログラム生成の計算時に一般的に用いられるGerchberg-Saxton(GS)法のような繰り返しアルゴリズムを適用することによって、目標ビーム投射パターンの再現性が向上する。
As shown in FIG. 4, in the phase modulation layer n04-m, the rotation angle φ (x, y) around the lattice point O (x, y) of the gravity center G1 of the different refractive index region n04-mb is the target. It is set independently for each unit configuration region R according to the beam projection pattern (light image). The rotation angle φ (x, y) has a specific value in the unit configuration region R (x, y), but is not necessarily represented by a specific function. That is, the rotation angle φ (x, y) is determined from the phase term of the complex amplitude obtained by converting the target beam projection pattern onto the wave number space and performing a two-dimensional inverse Fourier transform on a certain wave number range of the wave number space. The In addition, when obtaining a complex amplitude distribution (complex amplitude of each unit component region R) from the target beam projection pattern, an iterative algorithm such as the Gerchberg-Saxton (GS) method generally used at the time of hologram generation calculation is applied. By doing so, the reproducibility of the target beam projection pattern is improved.
図6は、半導体発光素子100から出力される目標ビーム投射パターン(光像)と、位相変調層n04-mにおける回転角度φ(x,y)の分布との関係を説明するための図である。具体的には、目標ビーム投射パターンの投射範囲である目標ビーム投射領域(XYZ直交座標系における座標(x,y,z)で表現される設計上の光像の設置面)を波数空間上に変換して得られるKx-Ky平面について考える。このKx-Ky平面を規定するKx軸およびKy軸は、互いに直交するとともに、それぞれが、目標ビーム投射パターンの投射方向を第1面100aの法線方向(Z軸方向)から該第1面100aまで振った時の該法線方向に対する角度に、上記式(1)~式(5)によって対応付けられている。このKx-Ky平面上において、目標ビーム投射パターンを含む特定領域が、それぞれが正方形状のM2(1以上の整数)×N2(1以上の整数)個の画像領域FRで構成されるものとする。また、位相変調層n04-m上のX-Y平面上において設定された仮想的な正方格子が、M1(1以上の整数)×N1(1以上の整数)個の単位構成領域Rにより構成されるものとする。なお、整数M2は、整数M1と一致する必要はない。同様に、整数N2は、整数N1と一致する必要もない。このとき、Kx軸方向の座標成分kx(1以上M2以下の整数)とKy軸方向の座標成分ky(1以上N2以下の整数)とで特定される、Kx-Ky平面における画像領域FR(kx,ky)それぞれを、X軸方向の座標成分x(1以上M1以下の整数)とY軸方向の座標成分y(1以上N1以下の整数)とで特定される単位構成領域R(x,y)に二次元逆フーリエ変換した、単位構成領域R(x,y)における複素振幅F(x,y)が、jを虚数単位として、以下の式(8)で与えられる。
FIG. 6 is a diagram for explaining the relationship between the target beam projection pattern (light image) output from the semiconductor light emitting element 100 and the distribution of the rotation angle φ (x, y) in the phase modulation layer n04-m. . Specifically, the target beam projection area (the installation surface of the design optical image expressed by the coordinates (x, y, z) in the XYZ orthogonal coordinate system), which is the projection range of the target beam projection pattern, is placed on the wave number space. Consider the Kx-Ky plane obtained by conversion. The Kx axis and the Ky axis that define the Kx-Ky plane are perpendicular to each other, and the projection direction of the target beam projection pattern is changed from the normal direction (Z-axis direction) of the first surface 100a to the first surface 100a. Is correlated with the angle with respect to the normal direction when swung up to (1) to (5). On the Kx-Ky plane, the specific area including the target beam projection pattern is composed of M2 (an integer greater than or equal to 1) × N2 (an integer greater than or equal to 1) image areas FR each having a square shape. . Further, a virtual square lattice set on the XY plane on the phase modulation layer n04-m is configured by M1 (an integer of 1 or more) × N1 (an integer of 1 or more) unit configuration regions R. Shall be. Note that the integer M2 need not match the integer M1. Similarly, the integer N2 need not match the integer N1. At this time, the image region FR in the Kx-Ky plane is specified by the coordinate component k x in the Kx axis direction (an integer of 1 to M2) and the coordinate component k y in the Ky axis direction (an integer of 1 to N2). Each of (k x , k y ) is a unit component region R identified by a coordinate component x in the X-axis direction (an integer from 1 to M1) and a coordinate component y in the Y-axis direction (an integer from 1 to N1). The complex amplitude F (x, y) in the unit configuration region R (x, y) obtained by two-dimensional inverse Fourier transform to (x, y) is given by the following equation (8), where j is an imaginary unit.
また、単位構成領域R(x,y)において、振幅項をA(x,y)および位相項をP(x,y)とするとき、該複素振幅F(x,y)が、以下の式(9)により規定される。
In the unit configuration region R (x, y), when the amplitude term is A (x, y) and the phase term is P (x, y), the complex amplitude F (x, y) is expressed by the following equation. It is defined by (9).
図6に示されたように、座標成分x=1~M1およびy=1~N1の範囲において、単位構成領域R(x,y)の複素振幅F(x,y)における振幅項をA(x,y)の分布が、X-Y平面上における強度分布に相当する。また、x=1~M1,y=1~N1の範囲において、単位構成領域R(x,y)の複素振幅F(x,y)における位相項をP(x,y)の分布が、X-Y平面上における位相分布に相当する。単位構成領域R(x,y)における回転角度φ(x,y)は、後述するように、P(x,y)から得られ、座標成分x=1~M1およびy=1~N1の範囲において、単位構成領域R(x,y)の回転角度φ(x,y)の分布が、X-Y平面上における回転角度分布に相当する。
As shown in FIG. 6, in the range of coordinate components x = 1 to M1 and y = 1 to N1, the amplitude term in the complex amplitude F (x, y) of the unit configuration region R (x, y) is A ( The distribution of x, y) corresponds to the intensity distribution on the XY plane. In addition, in the range of x = 1 to M1, y = 1 to N1, the phase term in the complex amplitude F (x, y) of the unit configuration region R (x, y) is expressed as the distribution of P (x, y), Corresponds to the phase distribution on the -Y plane. As will be described later, the rotation angle φ (x, y) in the unit configuration region R (x, y) is obtained from P (x, y), and ranges of coordinate components x = 1 to M1 and y = 1 to N1. , The distribution of the rotation angle φ (x, y) of the unit configuration region R (x, y) corresponds to the rotation angle distribution on the XY plane.
なお、Kx-Ky平面上におけるビーム投射パターンの中心Qは第1面100aに対して垂直な軸線上に位置しており、図6には、中心Qを原点とする4つの象限が示されている。図6では、一例として第1象限および第3象限に光像が得られる場合が示されたが、第2象限および第4象限、あるいは、全ての象限で像を得ることも可能である。本実施形態では、図6に示されたように、原点に関して点対称なパターンが得られる。図6は、一例として、第3象限に文字「A」が、第1象限に文字「A」を180°回転したパターンが、それぞれ得られる場合について示されている。なお、回転対称な光像(例えば、十字、丸、二重丸など)である場合には、重なって一つの光像として観察される。
Note that the center Q of the beam projection pattern on the Kx-Ky plane is located on an axis perpendicular to the first surface 100a, and FIG. 6 shows four quadrants with the center Q as the origin. Yes. In FIG. 6, as an example, a case where a light image is obtained in the first quadrant and the third quadrant is shown, but it is also possible to obtain images in the second quadrant and the fourth quadrant, or all quadrants. In the present embodiment, as shown in FIG. 6, a point-symmetric pattern with respect to the origin is obtained. FIG. 6 shows, as an example, a case where a character “A” is obtained in the third quadrant and a pattern obtained by rotating the character “A” 180 ° in the first quadrant is obtained. In addition, in the case of a rotationally symmetric optical image (for example, a cross, a circle, a double circle, etc.), they are overlapped and observed as one optical image.
半導体発光素子100から出力されたビーム投射パターン(光像)は、スポット、3点以上からなるスポット群、直線、十字架、線画、格子パターン、写真、縞状パターン、CG(コンピュータグラフィクス)、および文字のうち少なくとも1つで表現される設計上の光像(元画像)に対応した光像となる。ここで、目標ビーム投射パターンを得るためには、以下の手順によって単位構成領域R(x,y)における異屈折率領域n04-mbの回転角度φ(x、y)を決定する。
The beam projection pattern (light image) output from the semiconductor light emitting device 100 is a spot, a spot group consisting of three or more points, a straight line, a cross, a line drawing, a lattice pattern, a photograph, a striped pattern, CG (computer graphics), and characters. The optical image corresponds to the designed optical image (original image) expressed by at least one of the above. Here, in order to obtain the target beam projection pattern, the rotation angle φ (x, y) of the different refractive index region n04-mb in the unit configuration region R (x, y) is determined by the following procedure.
単位構成領域R(x,y)内では、上述のように、異屈折率領域n04-mbの重心G1が格子点O(x,y)から距離r(r(x,y)の値)だけ離れた状態で配置されている。このとき、単位構成領域R(x,y)内には、回転角度φ(x,y)が、以下の関係を満たすように異屈折率領域n04-mbは配置される。
φ(x,y)=C×P(x,y)+B
C:比例定数であって例えば180°/π
B:任意の定数であって例えば0
なお、比例定数Cおよび任意の定数Bは、全ての単位構成領域Rに対して同一の値である。 In the unit configuration region R (x, y), as described above, the center of gravity G1 of the different refractive index region n04-mb is only the distance r (value of r (x, y)) from the lattice point O (x, y). They are placed apart. At this time, the different refractive index regions n04-mb are arranged in the unit configuration region R (x, y) so that the rotation angle φ (x, y) satisfies the following relationship.
φ (x, y) = C × P (x, y) + B
C: proportional constant, for example 180 ° / π
B: Arbitrary constant, for example 0
Note that the proportionality constant C and the arbitrary constant B are the same value for all unit constituent regions R.
φ(x,y)=C×P(x,y)+B
C:比例定数であって例えば180°/π
B:任意の定数であって例えば0
なお、比例定数Cおよび任意の定数Bは、全ての単位構成領域Rに対して同一の値である。 In the unit configuration region R (x, y), as described above, the center of gravity G1 of the different refractive index region n04-mb is only the distance r (value of r (x, y)) from the lattice point O (x, y). They are placed apart. At this time, the different refractive index regions n04-mb are arranged in the unit configuration region R (x, y) so that the rotation angle φ (x, y) satisfies the following relationship.
φ (x, y) = C × P (x, y) + B
C: proportional constant, for example 180 ° / π
B: Arbitrary constant, for example 0
Note that the proportionality constant C and the arbitrary constant B are the same value for all unit constituent regions R.
すなわち、目標ビーム投射パターンを得たい場合、波数空間上に射影されたKx-Ky平面上に形成されるパターンを位相変調層n04-m上のX-Y平面上の単位構成領域R(x,y)に二次元逆フーリエ変換し、その複素振幅F(x,y)の位相項P(x,y)に対応した回転角度φ(x,y)を、該単位構成領域R(x,y)内に配置される異屈折率領域n04-mbに与えればよい。なお、レーザビームの二次元逆フーリエ変換後の遠視野像は、単一若しくは複数のスポット形状、円環形状、直線形状、文字形状、二重円環形状、または、ラゲールガウスビーム形状などの各種の形状をとることができる。なお、目標ビーム投射パターンは波数空間上における波数情報で表わされるものであるので(Kx-Ky平面上)、該目標ビーム投射パターンが二次元的な位置情報で表わされているビットマップ画像などの場合には、一旦波数情報に変換した後に二次元逆フーリエ変換を行うとよい。
That is, when it is desired to obtain a target beam projection pattern, a pattern formed on the Kx-Ky plane projected on the wave number space is converted into a unit configuration region R (x, Y on the XY plane on the phase modulation layer n04-m. y) is subjected to two-dimensional inverse Fourier transform, and the rotation angle φ (x, y) corresponding to the phase term P (x, y) of the complex amplitude F (x, y) is converted into the unit configuration region R (x, y). ) May be applied to the different refractive index region n04-mb arranged in the parentheses. The far-field image of the laser beam after the two-dimensional inverse Fourier transform can be a single or multiple spot shape, circular shape, linear shape, character shape, double annular shape, or Laguerre Gaussian beam shape. The shape can be taken. Since the target beam projection pattern is represented by wave number information in the wave number space (on the Kx-Ky plane), a bitmap image in which the target beam projection pattern is represented by two-dimensional position information, etc. In this case, it is preferable to perform two-dimensional inverse Fourier transform after first converting to wave number information.
二次元逆フーリエ変換で得られた、X-Y平面上における複素振幅分布から強度分布と位相分布を得る方法としては、例えば強度分布(X-Y平面上における振幅項A(x,y)の分布)については、MathWorks社の数値解析ソフトウェア「MATLAB」のabs関数を用いることにより計算することができ、位相分布(X-Y平面上における位相項P(x,y)の分布)については、MATLABのangle関数を用いることにより計算することができる。
As a method of obtaining the intensity distribution and the phase distribution from the complex amplitude distribution on the XY plane obtained by the two-dimensional inverse Fourier transform, for example, the intensity distribution (the amplitude term A (x, y) on the XY plane) Distribution) can be calculated by using the abs function of MathWorks' numerical analysis software “MATLAB”, and the phase distribution (the distribution of the phase term P (x, y) on the XY plane) It can be calculated by using the angle function of MATLAB.
上述のように、異屈折率領域n04-mbの配置パターンを定めれば、半導体発光素子100の第1面100aから目標ビーム投射領域と目標ビーム投射パターンの光がビーム投射領域へと出力され得る。目標ビーム投射パターンは、設計者が任意に定めることが可能で、スポット、3点以上からなるスポット群、直線、線画、十字架、図形、写真、CG(コンピュータグラフィックス)、文字、等であり得る。各位相変調領域のX―Y平面内において、全ての異屈折率領域n04-mbは、同一の図形、同一の面積、および/または、同一の距離r、を有する。また、複数の異屈折率領域n04-bは、並進操作、または、並進操作と回転操作の組み合わせにより、重ね合わせることができるように形成されていてもよい。この場合、ビーム投射領域内におけるノイズ光およびノイズとなる0次光の発生を抑制することができる。ここで0次光とは、Z軸方向に平行に出力する光であり、位相変調層n04-mにおいて位相変調されない光のことである。
As described above, if the arrangement pattern of the different refractive index regions n04-mb is determined, light of the target beam projection region and the target beam projection pattern can be output from the first surface 100a of the semiconductor light emitting device 100 to the beam projection region. . The target beam projection pattern can be arbitrarily determined by the designer, and can be a spot, a spot group consisting of three or more points, a straight line, a line drawing, a cross, a figure, a photograph, CG (computer graphics), a character, and the like. . In the XY plane of each phase modulation region, all the different refractive index regions n04-mb have the same figure, the same area, and / or the same distance r. Further, the plurality of different refractive index regions n04-b may be formed so as to be superposed by a translation operation or a combination of a translation operation and a rotation operation. In this case, generation of noise light and zero-order light that becomes noise in the beam projection region can be suppressed. Here, the 0th-order light is light that is output in parallel with the Z-axis direction, and is light that is not phase-modulated in the phase modulation layer n04-m.
ここで、図7に、目標ビーム投射パターンと、それに対応する元パターンを逆フーリエ変換して得られた複素振幅分布のうちの位相分布の一例を示す。図7(a)は第2面側電極108-1から駆動電流が供給されたときに得られる目標ビーム投射パターンの一例、図7(b)は第2面側電極108-2から駆動電流が供給されたときに得られる目標ビーム投射パターンの一例を示している。図7(c)および図7(d)は、それぞれ、図7(a)および図7(b)の各ビーム投射パターンに対応する元パターンを逆フーリエ変換して得られた複素振幅分布のうちの位相分布を示している。図7(c)および図7(d)は、何れも704×704の要素で構成されており、色の濃淡によって0~2πの角度の分布を表している。色が黒い部分が角度0を表している。
Here, FIG. 7 shows an example of the phase distribution of the complex amplitude distribution obtained by inverse Fourier transform of the target beam projection pattern and the corresponding original pattern. FIG. 7A shows an example of a target beam projection pattern obtained when a driving current is supplied from the second surface side electrode 108-1, and FIG. 7B shows an example of a driving current from the second surface side electrode 108-2. An example of a target beam projection pattern obtained when supplied is shown. FIGS. 7 (c) and 7 (d) show complex amplitude distributions obtained by inverse Fourier transform of the original patterns corresponding to the beam projection patterns in FIGS. 7 (a) and 7 (b), respectively. The phase distribution of is shown. Both FIG. 7C and FIG. 7D are composed of elements of 704 × 704, and represent an angle distribution of 0 to 2π depending on color shading. The black part represents the angle 0.
次に図8を参照して、半導体発光素子100を備える発光装置について説明する。図8は半導体発光素子100を備える発光装置の構成を示すブロック図である。図8に示されたように、発光装置140は、半導体発光素子100と、電源回路141と、制御信号入力回路142と、駆動回路143と、を備える。電源回路141は、駆動回路143と半導体発光素子100に電源を供給する。制御信号入力回路142は、発光装置140の外部から供給される制御信号を駆動回路143へ伝達する。駆動回路143は、半導体発光素子100に駆動電流を供給する。駆動回路143と半導体発光素子100とは、駆動電流を供給する2本の駆動ライン144-1、144-2と1本の共通電位ライン145により接続されている。駆動ライン144-1、144-2は、第2面側電極108-1、108-2にそれぞれ接続されている。共通電位ライン145は、第1面側電極110に接続されている。なお、図8において、駆動回路143の上に示された半導体発光素子100と駆動回路143の下に示された半導体発光素子100は、それぞれ、1つの半導体発光素子100の第1面と第2面を表している。
Next, a light-emitting device including the semiconductor light-emitting element 100 will be described with reference to FIG. FIG. 8 is a block diagram illustrating a configuration of a light emitting device including the semiconductor light emitting element 100. As shown in FIG. 8, the light emitting device 140 includes the semiconductor light emitting element 100, a power supply circuit 141, a control signal input circuit 142, and a drive circuit 143. The power supply circuit 141 supplies power to the drive circuit 143 and the semiconductor light emitting element 100. The control signal input circuit 142 transmits a control signal supplied from the outside of the light emitting device 140 to the drive circuit 143. The drive circuit 143 supplies a drive current to the semiconductor light emitting element 100. The drive circuit 143 and the semiconductor light emitting device 100 are connected by two drive lines 144-1 and 144-2 for supplying a drive current and one common potential line 145. The drive lines 144-1 and 144-2 are connected to the second surface side electrodes 108-1 and 108-2, respectively. The common potential line 145 is connected to the first surface side electrode 110. In FIG. 8, the semiconductor light emitting device 100 shown above the drive circuit 143 and the semiconductor light emitting device 100 shown below the drive circuit 143 are respectively the first surface and the second surface of one semiconductor light emitting device 100. Represents a surface.
駆動ライン144-1、144-2は、用途に応じて、択一的に駆動されてもよいし、同時に駆動されてもよい。また、駆動回路143は、半導体発光素子100とは別体で構成されてもよいし、半導体発光素子100の共通基板層101上に一体的に形成されてもよい。
The drive lines 144-1 and 144-2 may be driven alternatively or simultaneously according to the application. In addition, the drive circuit 143 may be configured separately from the semiconductor light emitting element 100 or may be integrally formed on the common substrate layer 101 of the semiconductor light emitting element 100.
以上のように構成された半導体発光素子100を備える発光装置140は、次のように動作する。すなわち、駆動回路143から駆動ライン144-1、144-2の何れかと共通電位ライン145の間に駆動電流が供給される。駆動電流が供給された駆動ラインに接続された第2面側電極に対応する発光部では、活性層103において電子と正孔の再結合が生じ、その発光部における活性層103が発光する。その発光により得られた光は、第1クラッド層102と第2クラッド層106によって効率的に閉じ込められる。活性層103から出射された光は、対応する位相変調領域の内部に入射し、位相変調領域による二次元的なフィードバックによる閉じ込め効果によって所定のモードが形成される。活性層に十分な電子と正孔を注入することによって、位相変調領域に入射した光は所定のモードで発振する。所定の発振モードを形成した光は、異屈折率領域の配置パターンに応じた位相変調を受け、位相変調を受けた光が、配置パターンに応じたビーム投射パターンを表現する光として第1面側電極側から外部(ビーム投射領域)に出射される。
The light emitting device 140 including the semiconductor light emitting element 100 configured as described above operates as follows. That is, a drive current is supplied from the drive circuit 143 between any of the drive lines 144-1 and 144-2 and the common potential line 145. In the light emitting portion corresponding to the second surface side electrode connected to the drive line supplied with the drive current, recombination of electrons and holes occurs in the active layer 103, and the active layer 103 in the light emitting portion emits light. The light obtained by the light emission is efficiently confined by the first cladding layer 102 and the second cladding layer 106. The light emitted from the active layer 103 enters the corresponding phase modulation region, and a predetermined mode is formed by the confinement effect by two-dimensional feedback by the phase modulation region. By injecting sufficient electrons and holes into the active layer, the light incident on the phase modulation region oscillates in a predetermined mode. The light having a predetermined oscillation mode undergoes phase modulation according to the arrangement pattern of the different refractive index regions, and the light subjected to the phase modulation is the first surface side as light expressing a beam projection pattern according to the arrangement pattern. The light is emitted from the electrode side to the outside (beam projection region).
本実施形態では、半導体発光素子100が一対の位相変調領域104-1、104-2を有する位相変調層104を備えた単一の素子である。そのため、それぞれ一つの位相変調領域(位相変調層)を備える複数の半導体発光素子が支持基板上に配置されている構成とは違い、複数の半導体発光素子が支持基板上に配置される過程が必要とされない。したがって、本実施形態によれば、目標ビーム投射領域への目標ビーム投射パターンの光の照射が容易かつ高精度に実現される。
In this embodiment, the semiconductor light emitting device 100 is a single device including the phase modulation layer 104 having a pair of phase modulation regions 104-1 and 104-2. Therefore, unlike a configuration in which a plurality of semiconductor light emitting elements each having one phase modulation region (phase modulation layer) are arranged on the support substrate, a process in which the plurality of semiconductor light emitting elements are arranged on the support substrate is necessary. And not. Therefore, according to this embodiment, the irradiation of the light of the target beam projection pattern to the target beam projection area is easily and highly accurately realized.
また、本実施形態では、活性層103、位相変調層104、第1クラッド層102、第2クラッド層106、および共通基板層101には、Z軸方向から見たときに位相変調領域104-1、104-2と重なる対応領域間を電気的および光学的に分離する分離領域112が設けられている。隣接する位相変調領域104-1、104-2は、分離領域112によって電気的および光学的に分離されるので、隣接する位相変調領域104-1、104-2間でのクロストークの発生が抑制される。この結果、所望のビーム投射領域への所望のビーム投射パターンの光の照射が、より一層高精度で実現される。
In the present embodiment, the active layer 103, the phase modulation layer 104, the first cladding layer 102, the second cladding layer 106, and the common substrate layer 101 have the phase modulation region 104-1 when viewed from the Z-axis direction. , 104-2 is provided with a separation region 112 for electrically and optically separating the corresponding regions. The adjacent phase modulation regions 104-1 and 104-2 are electrically and optically separated by the separation region 112, so that the occurrence of crosstalk between the adjacent phase modulation regions 104-1 and 104-2 is suppressed. Is done. As a result, irradiation of the light of the desired beam projection pattern to the desired beam projection region is realized with higher accuracy.
本実施形態では、第2面側電極108-1、108-2の何れから駆動電流が供給された場合にもビーム投射領域が等しくなるように、位相変調領域104-1、104-2それぞれにおける配置パターンが設定されていてもよい(ただし、ビーム投射パターンは任意)。このような構成では、特許文献1に示された半導体発光素子の応用例(レーザビームを対象物に対して走査するようにした応用例)以外への各種の応用が可能となる。例えば、本字氏形態によれば、(ア)スクリーンの同じ領域に2つのパターンを切替表示するタイプの各種表示装置への応用、(イ)一箇所に同じパターンの光を継続的あるいは断続的に照射するタイプの各種照明への応用、(ウ)一箇所に同じパターンのパルス光を連続的に照射することで対象物に目標パターンの穴を穿設するタイプのレーザ加工への応用が可能である。
In the present embodiment, in each of the phase modulation regions 104-1 and 104-2, the beam projection regions are equal even when the drive current is supplied from any of the second surface side electrodes 108-1 and 108-2. An arrangement pattern may be set (however, the beam projection pattern is arbitrary). With such a configuration, various applications other than the application example (application example in which a laser beam is scanned with respect to an object) of the semiconductor light emitting device disclosed in Patent Document 1 are possible. For example, according to this form, (a) application to various types of display devices that switch and display two patterns in the same area of the screen, (b) continuous or intermittent light of the same pattern in one place Can be applied to various types of illumination that irradiate the target, and (c) laser processing that punctures the target pattern in the target object by continuously irradiating the same pattern of pulsed light at one location. It is.
第1実施形態における応用(ア)の例としては、図7(a)に示されたような×のパターンと図7(b)に示されたような○のパターンを、ユーザの指示または適宜のタイミングでスクリーンの同じ位置に切替表示するような応用がある。
As an example of application (a) in the first embodiment, a pattern of “X” as shown in FIG. 7A and a pattern of “◯” as shown in FIG. There are applications that switch and display at the same position on the screen at the same timing.
第1実施形態における応用(イ)の例としては、第1位相変調領域104-1における配置パターンと第2位相変調領域104-2における配置パターンの両方が、同じビーム投射領域、同じビーム投射パターンが得られるように設定される。なお、ビーム投射パターンは例えばビーム投射領域の全体あるいは一部にわたって均一な明るさを有するようなビーム投射パターンとする。明るい照明が必要な場合には第2面側電極108-1、108-2の両方から駆動電流を供給し、暗い照明で足りる場合には第2面側電極108-1、108-2の何れか一方のみから駆動電流を供給する、といった応用がある。
As an example of application (A) in the first embodiment, both the arrangement pattern in the first phase modulation area 104-1 and the arrangement pattern in the second phase modulation area 104-2 are the same beam projection area and the same beam projection pattern. Is set to be obtained. The beam projection pattern is, for example, a beam projection pattern having uniform brightness over the whole or part of the beam projection area. When bright illumination is required, a drive current is supplied from both the second surface side electrodes 108-1 and 108-2. When dark illumination is sufficient, either of the second surface side electrodes 108-1 and 108-2 is used. There is an application in which a drive current is supplied from only one of them.
第1実施形態における応用(ウ)の例としては、第1位相変調領域104-1における配置パターンと第2位相変調領域104-2における配置パターンの両方が、同じビーム投射領域同じビーム投射パターンが得られるように設定される。なお、ビーム投射領域は被加工物の穴を穿設したい位置に合わせ、ビーム投射パターンは穿設したい穴の形状のパターンとする。第2面側電極108-1、108-2の双方から交互にパルス電流を供給する、といった応用がある。この場合、それぞれの発光部のパルス間隔を長くできる。そのため、それぞれの発光部からより高いピーク出力を得ることが可能となり、より大出力を得ることが可能となる。
As an example of application (c) in the first embodiment, both the arrangement pattern in the first phase modulation area 104-1 and the arrangement pattern in the second phase modulation area 104-2 have the same beam projection pattern in the same beam projection area. It is set to be obtained. The beam projection area is matched with the position where the hole of the workpiece is to be drilled, and the beam projection pattern is a pattern of the shape of the hole to be drilled. There is an application in which a pulse current is alternately supplied from both of the second surface side electrodes 108-1 and 108-2. In this case, the pulse interval of each light emitting part can be increased. For this reason, it is possible to obtain a higher peak output from each light emitting unit, and it is possible to obtain a larger output.
また、本実施形態においては、第2面側電極108-1、108-2の何れから駆動電流が供給された場合にもビーム投射パターンが等しくなるように、位相変調領域104-1、104-2それぞれにおける配置パターンが定められていてもよい(ただし、ビーム投射領域は任意)。このような構成の場合にも、特許文献1に示された半導体発光素子の応用例(レーザビームを対象物に対して走査するようにした応用例)以外への各種の応用が可能となる。例えば、上述の応用(ア)~応用(ウ)の他、2つの個所を適宜のタイミングで照射するタイプの照明等への応用も可能となる。
Further, in the present embodiment, the phase modulation regions 104-1 and 104- are set so that the beam projection patterns are equal even when the drive current is supplied from any of the second surface side electrodes 108-1 and 108-2. The arrangement pattern in each of the two may be determined (however, the beam projection area is arbitrary). Even in such a configuration, various applications other than the application example (application example in which the laser beam is scanned with respect to the object) of the semiconductor light emitting element disclosed in Patent Document 1 are possible. For example, in addition to the above-described applications (a) to (c), it is possible to apply to illumination of a type that irradiates two places at an appropriate timing.
(第2実施形態)
第2実施形態は、第1実施形態において2つ(一対)であった位相変調領域と第2面側電極の組を3つ以上に有し、それらを一次元に配置した実施形態である。換言すれば、この第2実施形態は、第1実施形態では2つであった発光部を3つ以上に増加させて、更に発光部を一次元に配置した実施形態であり、そのように変更した点以外は第1実施形態と同様である。 (Second Embodiment)
The second embodiment is an embodiment in which there are three or more pairs of phase modulation regions and second surface side electrodes that are two (a pair) in the first embodiment, and they are arranged one-dimensionally. In other words, the second embodiment is an embodiment in which the number of the light emitting units, which was two in the first embodiment, is increased to three or more and the light emitting units are arranged one-dimensionally. Except for this point, the second embodiment is the same as the first embodiment.
第2実施形態は、第1実施形態において2つ(一対)であった位相変調領域と第2面側電極の組を3つ以上に有し、それらを一次元に配置した実施形態である。換言すれば、この第2実施形態は、第1実施形態では2つであった発光部を3つ以上に増加させて、更に発光部を一次元に配置した実施形態であり、そのように変更した点以外は第1実施形態と同様である。 (Second Embodiment)
The second embodiment is an embodiment in which there are three or more pairs of phase modulation regions and second surface side electrodes that are two (a pair) in the first embodiment, and they are arranged one-dimensionally. In other words, the second embodiment is an embodiment in which the number of the light emitting units, which was two in the first embodiment, is increased to three or more and the light emitting units are arranged one-dimensionally. Except for this point, the second embodiment is the same as the first embodiment.
図9~図11を参照して、第2実施形態に係る半導体発光素子200の構成を説明する。図9は、第2実施形態に係る半導体発光素子200を第1面側から見た図である。図10は、半導体発光素子200を第2面側から見た図である。図11は、図9および図10のX-X線に沿っての断面図である。図9~図11には5つの発光部(第1発光部~第5発光部)が直線上に並んでいる例が示されているが、発光部の数は5つ以外であってもよく、また、一次元の配置は曲線上であってもよい。
A configuration of the semiconductor light emitting device 200 according to the second embodiment will be described with reference to FIGS. FIG. 9 is a view of the semiconductor light emitting device 200 according to the second embodiment as viewed from the first surface side. FIG. 10 is a view of the semiconductor light emitting device 200 as viewed from the second surface side. FIG. 11 is a cross-sectional view taken along line XX of FIGS. 9 to 11 show an example in which five light emitting units (first light emitting unit to fifth light emitting unit) are arranged in a straight line, but the number of light emitting units may be other than five. The one-dimensional arrangement may be on a curve.
図9~図11に示されたように、半導体発光素子200は、第1面200aと第2面200bとを有し、光出射面として第1面200aから光を出力する。なお、本実施形態において、第2面200bはサポート面として機能する。半導体発光素子200は、共通基板層201と、活性層203と、位相変調層204と、第1クラッド層202と、第2クラッド層206と、複数の第2面側電極208-1~208-5と、第1面側電極210と、を備える。位相変調層204は、活性層203と光学的に結合される複数の位相変調領域204-1~204-5を有する。なお、少なくとも、活性層203と複数の位相変調領域204-1~204-5を含む位相変調層204により積層構造体が構成されている。第1クラッド層202は、積層構造体(少なくとも、活性層203と位相変調層204を含む)に対して第1面200aが配置された側に位置する。第2クラッド層206は、積層構造体(少なくとも、活性層203と位相変調層204を含む)に対して第2面200bが配置された側に位置する。第2面側電極208-1~208-5は、第2クラッド層206に対して第2面200bが配置された側であって、位相変調領域204-1~204-5それぞれに対応する位置に配置されている。第1面側電極210は、第1クラッド層202に対して第1面200aが配置された側に位置する。
9 to 11, the semiconductor light emitting device 200 has a first surface 200a and a second surface 200b, and outputs light from the first surface 200a as a light emitting surface. In the present embodiment, the second surface 200b functions as a support surface. The semiconductor light emitting device 200 includes a common substrate layer 201, an active layer 203, a phase modulation layer 204, a first cladding layer 202, a second cladding layer 206, and a plurality of second surface side electrodes 208-1 to 208-. 5 and the first surface side electrode 210. The phase modulation layer 204 includes a plurality of phase modulation regions 204-1 to 204-5 that are optically coupled to the active layer 203. Note that a laminated structure is configured by at least the active layer 203 and the phase modulation layer 204 including the plurality of phase modulation regions 204-1 to 204-5. The first cladding layer 202 is located on the side where the first surface 200a is disposed with respect to the laminated structure (including at least the active layer 203 and the phase modulation layer 204). The second cladding layer 206 is located on the side where the second surface 200b is disposed with respect to the stacked structure (including at least the active layer 203 and the phase modulation layer 204). The second surface side electrodes 208-1 to 208-5 are on the side where the second surface 200b is disposed with respect to the second cladding layer 206, and positions corresponding to the phase modulation regions 204-1 to 204-5, respectively. Is arranged. The first surface side electrode 210 is located on the side where the first surface 200 a is disposed with respect to the first cladding layer 202.
位相変調領域204-1~204-5は、それぞれ、第1屈折率を有する基本領域204-1a~204-5aと、第1屈折率とは異なる第2屈折率を有する複数の異屈折率領域204-1b~204-5bを含む。複数の異屈折率領域204-1b~204-5bは、それぞれの重心G1が基本領域204-1a~204-5a中の仮想的な正方格子における各格子点Oから所定の距離rだけずれた場所に位置するような配置パターンに従って、基本領域204-1a~204-5a中に配置される。位相変調領域204-1~204-5それぞれにおける異屈折率領域204-1b~204-5bの配置パターンは、当該位相変調領域204-1~204-5に対応する第2面側電極208-1~208-5から駆動電流が供給されたときに第1面200aから出力される光で表現されるビーム投射パターンと該ビーム投射パターンの投射範囲であるビーム投射が、目標ビーム投射パターンと目標ビーム投射領域となるように設定されている。
The phase modulation regions 204-1 to 204-5 respectively include basic regions 204-1a to 204-5a having a first refractive index and a plurality of different refractive index regions having a second refractive index different from the first refractive index. 204-1b to 204-5b. The plurality of different refractive index regions 204-1b to 204-5b are locations where the center of gravity G1 is shifted by a predetermined distance r from each lattice point O in the virtual square lattice in the basic regions 204-1a to 204-5a. Are arranged in the basic areas 204-1a to 204-5a according to the arrangement pattern as shown in FIG. The arrangement pattern of the different refractive index regions 204-1b to 204-5b in each of the phase modulation regions 204-1 to 204-5 is the second surface side electrode 208-1 corresponding to the phase modulation regions 204-1 to 204-5. The beam projection pattern expressed by the light output from the first surface 200a when the drive current is supplied from ˜208-5 and the beam projection that is the projection range of the beam projection pattern are the target beam projection pattern and the target beam. It is set to be a projection area.
第2面側電極208-1~208-5から駆動電流が供給されたときに出力される光のビーム投射領域は、全てが同じであってもよいし、少なくとも一部が他と異なっていてもよい。また、第2面側電極208-1~208-5から駆動電流が供給されたときに出力される光のビーム投射パターンも、全てが同じであってもよいし、少なくとも一部が他と異なっていてもよい。
The beam projection area of the light output when the driving current is supplied from the second surface side electrodes 208-1 to 208-5 may be all the same, or at least a part is different from the others. Also good. Further, the beam projection pattern of the light output when the drive current is supplied from the second surface side electrodes 208-1 to 208-5 may be all the same, or at least partly different from the others. It may be.
活性層203、位相変調層204、第1クラッド層202、第2クラッド層206、および共通基板層201には、第2面200bから共通基板層201に向かって、該共通基板層201に到達するまで伸びた分離領域212が設けられている。分離領域212は、Z軸方向(積層方向)から見たときに位相変調領域204-1~204-5と重なる、活性層203、第1クラッド層202、第2クラッド層206、第1クラッド層202、および第2クラッド層206それぞれにおける対応領域間を電気的および光学的に分離するよう、第2面200bから共通基板層201に向かって伸びている。共通基板層201のうち、分離領域212の下部に位置する部分の厚さ(分離領域212の第1面側電極210側の端面212aと第1面側電極210の間の最短距離)は、Z軸方向に沿った共通基板層201の厚さの半分以下であり、典型的には70μm以下である。図11に示されたように、分離領域212の位置で区切られる半導体発光素子100の各部分は、それぞれ独立した発光部(第1発光部~第5発光部)と看做すことができる。また、分離領域212の製造工程は、第1実施形態と同様である。
The active layer 203, the phase modulation layer 204, the first cladding layer 202, the second cladding layer 206, and the common substrate layer 201 reach the common substrate layer 201 from the second surface 200b toward the common substrate layer 201. A separation region 212 extending up to is provided. The isolation region 212 overlaps with the phase modulation regions 204-1 to 204-5 when viewed from the Z-axis direction (stacking direction), the active layer 203, the first cladding layer 202, the second cladding layer 206, and the first cladding layer. 202 and the second cladding layer 206 respectively extend from the second surface 200b toward the common substrate layer 201 so as to electrically and optically separate corresponding regions. The thickness of the portion of the common substrate layer 201 positioned below the isolation region 212 (the shortest distance between the end surface 212a of the isolation region 212 on the first surface side electrode 210 side and the first surface side electrode 210) is Z It is less than half of the thickness of the common substrate layer 201 along the axial direction, and typically less than 70 μm. As shown in FIG. 11, each part of the semiconductor light emitting device 100 divided by the position of the isolation region 212 can be regarded as an independent light emitting part (first light emitting part to fifth light emitting part). The manufacturing process of the separation region 212 is the same as that in the first embodiment.
第1面側電極210は、図9および図11に示されたように、位相変調領域204-1~204-5と第2面側電極208-1~208-5に対応する位置に開口部210-1~210-5を有している。第1面側電極210は、開口部を有する電極の代わりに、透明電極であってもよい。
As shown in FIGS. 9 and 11, the first surface side electrode 210 has openings at positions corresponding to the phase modulation regions 204-1 to 204-5 and the second surface side electrodes 208-1 to 208-5. 210-1 to 210-5. The first surface side electrode 210 may be a transparent electrode instead of an electrode having an opening.
活性層203と位相変調層204の上下関係は、図11に示された上下関係と逆であってもよい。また、図11には、共通基板層201、上部光ガイド層205b、下部光ガイド層205a、コンタクト層207、絶縁層209、反射防止層211も記載されているが、半導体発光素子200は、必ずしもこれらを備えている必要はない。
The vertical relationship between the active layer 203 and the phase modulation layer 204 may be opposite to the vertical relationship shown in FIG. FIG. 11 also shows the common substrate layer 201, the upper light guide layer 205b, the lower light guide layer 205a, the contact layer 207, the insulating layer 209, and the antireflection layer 211. It is not necessary to have these.
これまでに説明した各層、各領域の構成材料、形状、寸法、分離領域の製造工程を除く主要工程を含む製造方法等は、第1実施形態と同様に、特許文献1の記載内容に基づいて当業者が適宜選択可能であるが、以下にその一部の例を示す。すなわち、図11に示された各層の材料ないし構造の一例は、次のとおりである。共通基板層201はGaAsからなる。第1クラッド層202はAlGaAsからなる。活性層203は多重量子井戸構造MQW(障壁層:AlGaAs/井戸層:InGaAs)を有する。位相変調層204は、基本領域204-1a~204-5aと、該基本領域204-1a~204-5a内に埋め込まれた複数の異屈折率領域204-1b~204-5bを含む。基本領域204-1a~204-5aはGaAsからなる。複数の異屈折率領域204-1b~204-5bがAlGaAsからなる。上部光ガイド層205bおよび下部光ガイド層205aはAlGaAsからなる。第2クラッド層206はAlGaAsからなる。コンタクト層207はGaAsからなる。絶縁層209はSiO2またはシリコン窒化物からなる。反射防止層211は、窒化シリコン(SiN)、二酸化シリコン(SiO2)などの誘電体単層膜或いは誘電体多層膜からなる。分離領域212は、高強度光(電場)により改質された半導体層、不純物拡散およびイオン打ち込み法の何れかにより絶縁化された半導体層、または、ドライエッチングおよびウェットエッチングの何れかにより形成されたスリット(空隙)である。ここで、高強度光(電場)による改質の具体的手法としては、例えば、ナノ秒レーザによる加工や超短パルスレーザによる加工がある。複数の異屈折率領域204-1b~204-5bは、アルゴン、窒素または空気等が封入された空孔であってもよい。
The manufacturing method including the main processes excluding the manufacturing process of each layer, each region, the region, and the separation region described above is based on the description in Patent Document 1 as in the first embodiment. Those skilled in the art can appropriately select, but some examples are shown below. That is, an example of the material or structure of each layer shown in FIG. 11 is as follows. The common substrate layer 201 is made of GaAs. The first cladding layer 202 is made of AlGaAs. The active layer 203 has a multiple quantum well structure MQW (barrier layer: AlGaAs / well layer: InGaAs). The phase modulation layer 204 includes basic regions 204-1a to 204-5a and a plurality of different refractive index regions 204-1b to 204-5b embedded in the basic regions 204-1a to 204-5a. The basic regions 204-1a to 204-5a are made of GaAs. The plurality of different refractive index regions 204-1b to 204-5b are made of AlGaAs. The upper light guide layer 205b and the lower light guide layer 205a are made of AlGaAs. The second cladding layer 206 is made of AlGaAs. The contact layer 207 is made of GaAs. The insulating layer 209 is made of SiO 2 or silicon nitride. The antireflection layer 211 is made of a dielectric single layer film or dielectric multilayer film such as silicon nitride (SiN) or silicon dioxide (SiO 2 ). The isolation region 212 is formed by a semiconductor layer modified by high-intensity light (electric field), a semiconductor layer insulated by any of impurity diffusion and ion implantation, or any of dry etching and wet etching It is a slit (gap). Here, as a specific method of modification by high intensity light (electric field), there are, for example, processing by a nanosecond laser and processing by an ultrashort pulse laser. The plurality of different refractive index regions 204-1b to 204-5b may be holes filled with argon, nitrogen, air, or the like.
一例では、共通基板層201と第1クラッド層202には、N型の不純物が添加されている。第2クラッド層206とコンタクト層207には、P型の不純物が添加されている。また、第1クラッド層202と第2クラッド層206のエネルギーバンドギャップは、上部光ガイド層205bと下部光ガイド層205aのエネルギーバンドギャップよりも大きい。上部光ガイド層205bと下部光ガイド層205aのエネルギーバンドギャップは、活性層203の多重量子井戸構造MQWのエネルギーバンドギャップよりも大きく設定されている。
In one example, the common substrate layer 201 and the first cladding layer 202 are doped with N-type impurities. P-type impurities are added to the second cladding layer 206 and the contact layer 207. The energy band gap between the first cladding layer 202 and the second cladding layer 206 is larger than the energy band gap between the upper light guide layer 205b and the lower light guide layer 205a. The energy band gap of the upper light guide layer 205b and the lower light guide layer 205a is set to be larger than the energy band gap of the multiple quantum well structure MQW of the active layer 203.
ここで、図12および図13に、本実施形態および後述の第3実施形態において目標ビーム投射パターンと、それに対応する元パターンを逆フーリエ変換して得られた複素振幅分布のうちの位相分布の例を示す。図12(a)~図12(c)は、それぞれ、第1発光部、第3発光部、第5発光部の第2面側電極から駆動電流を供給したときに得られる目標ビーム投射パターンの一例を示している。図12(d)~図12(f)は、それぞれ、図12(a)~図12(c)の各ビーム投射パターンに対応する元パターンを逆フーリエ変換して得られた複素振幅分布のうちの位相分布を示している。図13(a)~図13(c)は、それぞれ、第1発光部、第3発光部、第5発光部の第2面側電極から駆動電流を供給したときに得られる目標ビーム投射パターンの別の一例を示している。図13(d)~図13(f)は、それぞれ、図13(a)~図13(c)の各ビーム投射パターンに対応する元パターンを逆フーリエ変換して得られた複素振幅分布のうちの位相分布を示している。図12(d)~図12(f)と図13(d)~図13(f)は、何れも704×704の要素で構成されており、色の濃淡によって0~2πの角度の分布を表している。色が黒い部分が角度0を表している。
Here, FIG. 12 and FIG. 13 show the phase distribution of the complex amplitude distribution obtained by performing inverse Fourier transform on the target beam projection pattern and the corresponding original pattern in the present embodiment and the third embodiment described later. An example is shown. 12A to 12C show target beam projection patterns obtained when a drive current is supplied from the second surface side electrodes of the first light emitting unit, the third light emitting unit, and the fifth light emitting unit, respectively. An example is shown. 12D to 12F show complex amplitude distributions obtained by performing inverse Fourier transform on the original patterns corresponding to the beam projection patterns in FIGS. 12A to 12C, respectively. The phase distribution of is shown. FIGS. 13A to 13C show target beam projection patterns obtained when a drive current is supplied from the second surface side electrodes of the first light emitting unit, the third light emitting unit, and the fifth light emitting unit, respectively. Another example is shown. FIGS. 13 (d) to 13 (f) show complex amplitude distributions obtained by performing inverse Fourier transform on the original patterns corresponding to the beam projection patterns in FIGS. 13 (a) to 13 (c), respectively. The phase distribution of is shown. 12 (d) to 12 (f) and FIGS. 13 (d) to 13 (f) are each composed of elements of 704 × 704, and the distribution of angles from 0 to 2π is represented by the color shade. Represents. The black part represents the angle 0.
次に、図14を参照して、半導体発光素子200を備える発光装置の構成を説明する。図14は半導体発光素子200を備える発光装置の構成を示すブロック図である。図14に示されたように、発光装置240は、半導体発光素子200と、電源回路241と、制御信号入力回路242と、駆動回路243と、を備える。電源回路241は、駆動回路243と半導体発光素子200に電源を供給する。制御信号入力回路242は、発光装置240の外部から供給される制御信号を駆動回路243へ伝達する。駆動回路243は、半導体発光素子200に駆動電流を供給する。駆動回路243と半導体発光素子200とは、駆動電流を供給する複数の駆動ライン244-1~244-5と1本の共通電位ライン245により接続されている。駆動ライン244-1~244-5は、第2面側電極208-1~208-5にそれぞれ接続されている。共通電位ライン245は第1面側電極210に接続されている。なお、図14において、駆動回路243の上に示された半導体発光素子200と駆動回路243の下に示された半導体発光素子200は、それぞれ、1つの半導体発光素子200の第1面と第2面を表している。
Next, with reference to FIG. 14, a configuration of a light emitting device including the semiconductor light emitting element 200 will be described. FIG. 14 is a block diagram illustrating a configuration of a light emitting device including the semiconductor light emitting element 200. As shown in FIG. 14, the light emitting device 240 includes a semiconductor light emitting element 200, a power supply circuit 241, a control signal input circuit 242, and a drive circuit 243. The power supply circuit 241 supplies power to the drive circuit 243 and the semiconductor light emitting element 200. The control signal input circuit 242 transmits a control signal supplied from the outside of the light emitting device 240 to the drive circuit 243. The drive circuit 243 supplies a drive current to the semiconductor light emitting element 200. The drive circuit 243 and the semiconductor light emitting element 200 are connected by a plurality of drive lines 244-1 to 244-5 for supplying a drive current and one common potential line 245. The drive lines 244-1 to 244-5 are connected to the second surface side electrodes 208-1 to 208-5, respectively. The common potential line 245 is connected to the first surface side electrode 210. In FIG. 14, the semiconductor light emitting element 200 shown above the drive circuit 243 and the semiconductor light emitting element 200 shown below the drive circuit 243 are respectively the first surface and the second surface of one semiconductor light emitting element 200. Represents a surface.
駆動ライン244-1~244-5は、用途に応じて、択一的に駆動されてもよいし、少なくとも2本が同時に駆動されてもよい。また、駆動回路243は、半導体発光素子200とは別体で構成されてもよいし、半導体発光素子200の共通基板層201上に一体的に形成されてもよい。
The drive lines 244-1 to 244-5 may be driven alternatively according to the application, or at least two may be driven simultaneously. In addition, the drive circuit 243 may be configured separately from the semiconductor light emitting element 200 or may be integrally formed on the common substrate layer 201 of the semiconductor light emitting element 200.
以上のように構成された半導体発光素子200を備える発光装置240は、次のように動作する。すなわち、駆動回路243から駆動ライン244-1~244-5の何れかと共通電位ライン245の間に駆動電流が供給される。駆動電流が供給された駆動ラインに接続された第2面側電極に対応する発光部では、活性層203において電子と正孔の再結合が生じ、その発光部における活性層203が発光する。その発光により得られた光は、第1クラッド層202と第2クラッド層206によって効率的に閉じ込められる。活性層203から出射された光は、対応する位相変調領域の内部に入射し、位相変調領域による2次元的なフィードバックによる閉じ込め効果によって所定のモードを形成する。活性層に十分な電子と正孔を注入することによって、位相変調領域に入射した光は所定のモードで発振する。所定の発振モードを形成した光は、異屈折率領域の配置パターンに応じた位相変調を受け、位相変調を受けた光が、配置パターンに応じたビーム投射パターンを表現する光として第1面側電極側から外部(ビーム投射領域)に出射される。
The light emitting device 240 including the semiconductor light emitting element 200 configured as described above operates as follows. That is, a drive current is supplied from the drive circuit 243 to any one of the drive lines 244-1 to 244-5 and the common potential line 245. In the light emitting portion corresponding to the second surface side electrode connected to the drive line supplied with the drive current, recombination of electrons and holes occurs in the active layer 203, and the active layer 203 in the light emitting portion emits light. The light obtained by the light emission is efficiently confined by the first cladding layer 202 and the second cladding layer 206. The light emitted from the active layer 203 enters the corresponding phase modulation region, and forms a predetermined mode by the confinement effect by two-dimensional feedback by the phase modulation region. By injecting sufficient electrons and holes into the active layer, the light incident on the phase modulation region oscillates in a predetermined mode. The light having a predetermined oscillation mode undergoes phase modulation according to the arrangement pattern of the different refractive index regions, and the light subjected to the phase modulation is the first surface side as light expressing a beam projection pattern according to the arrangement pattern. The light is emitted from the electrode side to the outside (beam projection region).
本実施形態においても、半導体発光素子200が複数の位相変調領域204-1~204-5を有する位相変調層204を備えた単一の素子である。そのため、それぞれ一つの位相変調領域(位相変調層)を備える複数の半導体発光素子が支持基板上に配置されている構成とは違い、複数の半導体発光素子が支持基板上に配置される過程が必要とされない。そのため、目標ビーム投射領域への目標ビーム投射パターンの光の照射が容易かつ高精度に実現される。
Also in this embodiment, the semiconductor light emitting device 200 is a single device including the phase modulation layer 204 having a plurality of phase modulation regions 204-1 to 204-5. Therefore, unlike a configuration in which a plurality of semiconductor light emitting elements each having one phase modulation region (phase modulation layer) are arranged on the support substrate, a process in which the plurality of semiconductor light emitting elements are arranged on the support substrate is necessary. And not. Therefore, the irradiation of the light of the target beam projection pattern to the target beam projection area can be realized easily and with high accuracy.
また、本実施形態においても、活性層203、位相変調層204、第1クラッド層202、第2クラッド層206、および共通基板層201に、第2面200bから共通基板層201に向かって、該共通基板層201に到達するまで伸びた分離領域212が設けられている。隣接する位相変調領域204-1~204-5は、分離領域212によって電気的および光学的に分離されるので、隣接する位相変調領域204-1~204-5間でのクロストークの発生が抑制される。この結果、所望のビーム投射領域への所望のビーム投射パターンの光の照射が、より一層高精度で実現される。
Also in the present embodiment, the active layer 203, the phase modulation layer 204, the first cladding layer 202, the second cladding layer 206, and the common substrate layer 201 are moved from the second surface 200b toward the common substrate layer 201. A separation region 212 extending until reaching the common substrate layer 201 is provided. The adjacent phase modulation regions 204-1 to 204-5 are electrically and optically separated by the separation region 212, so that the occurrence of crosstalk between the adjacent phase modulation regions 204-1 to 204-5 is suppressed. Is done. As a result, irradiation of the light of the desired beam projection pattern to the desired beam projection region is realized with higher accuracy.
また、本実施形態においても、第2面側電極208-1~208-5の何れから駆動電流が供給された場合にもビーム投射領域が等しくなるように、位相変調領域204-1~204-5それぞれにおける配置パターンが設定されてもよい(ただし、ビーム投射パターンは任意)。このような構成の場合には、特許文献1に示された半導体発光素子の応用例(レーザビームを対象物に対して走査するようにした応用例)以外への各種の応用が可能となる。例えば、本実施形態によれば、(ア)スクリーンの同じ領域に3つ以上の複数のパターンを切替表示するタイプの各種表示装置への応用、(イ)一箇所に同じパターンの光を継続的あるいは断続的に照射するタイプの各種照明への応用、(ウ)一箇所に同じパターンのパルス光を連続的に照射することで対象物に目標パターンの穴を穿設するタイプのレーザ加工への応用が可能である。
Also in the present embodiment, the phase modulation areas 204-1 to 204- are set so that the beam projection areas become equal when the drive current is supplied from any of the second surface side electrodes 208-1 to 208-5. 5 may be set (however, the beam projection pattern is arbitrary). In the case of such a configuration, various applications other than the application example (application example in which a laser beam is scanned with respect to an object) of the semiconductor light emitting element disclosed in Patent Document 1 are possible. For example, according to the present embodiment, (a) application to various types of display devices that switch and display a plurality of patterns of three or more in the same area of the screen, (b) continuous light of the same pattern in one place Or application to various types of illumination that irradiates intermittently, (c) laser processing of the type that drills holes of the target pattern in the object by continuously irradiating the same pattern of pulsed light to one place Application is possible.
第2実施形態における応用(ア)の例としては、図7(a)に示されたような×のパターンと図7(b)に示されたような○のパターンに加えて、△、□等のそれ以外のパターンを、ユーザの指示または適宜のタイミングでスクリーンの同じ位置に切替表示するような応用、図12および図13に示されたような少しずつ異なるパターンを連続的に切替表示することで1つの領域にアニメーションを表示するような応用、等がある。
As an example of the application (a) in the second embodiment, in addition to the pattern of X as shown in FIG. 7A and the pattern of O as shown in FIG. Other patterns such as the above are switched and displayed at the same position on the screen at the user's instruction or at an appropriate timing, and slightly different patterns as shown in FIGS. 12 and 13 are continuously switched and displayed. There are applications such as displaying animation in one area.
第2実施形態における応用(イ)の例としては、第1実施形態における応用(イ)として示された照明を、多段階に切替え可能に変更したような応用がある。
As an example of the application (A) in the second embodiment, there is an application in which the illumination shown as the application (A) in the first embodiment is changed so as to be switchable in multiple stages.
第3実施形態に置ける応用(ウ)の例としては、第1実施形態における応用(ウ)として示されたレーザ加工を、複数の第2面側電極を順次パルス駆動するように変更したような応用がある。この場合、それぞれの発光部のパルス間隔を長く出来るため、それぞれの発光部からより高いピーク出力を得ることが可能となり、より大出力を得ることが可能となる。
As an example of application (c) in the third embodiment, the laser processing shown as application (c) in the first embodiment is changed to sequentially drive a plurality of second surface side electrodes. There are applications. In this case, since the pulse interval of each light emitting part can be lengthened, it becomes possible to obtain a higher peak output from each light emitting part and to obtain a larger output.
また、本実施形態においても、第2面側電極208-1~208-5の何れから駆動電流が供給された場合にもビーム投射パターンが等しくなるように、位相変調領域204-1~204-5それぞれにおける配置パターンが設定されていてもよい(ただし、ビーム投射領域は任意)。このような構成の場合、特許文献1に示された半導体発光素子の応用例(レーザビームを対象物に対して走査するようにした応用例)と同様の応用が可能となる他、それとは異なる各種の応用も可能となる。特許文献1に示された応用例とは異なる応用としては、上述の応用(ア)~応用(ウ)の他、任意の個所を所望のタイミングで照射するタイプの照明への応用等も可能となる。
Also in the present embodiment, the phase modulation regions 204-1 to 204- are set so that the beam projection patterns are equal even when the drive current is supplied from any of the second surface side electrodes 208-1 to 208-5. 5 may be set (however, the beam projection area is arbitrary). In the case of such a configuration, an application similar to the application example of the semiconductor light emitting device disclosed in Patent Document 1 (application example in which the laser beam is scanned with respect to the object) is possible, and is different from that. Various applications are also possible. As applications different from the application example shown in Patent Document 1, in addition to the above-mentioned applications (a) to (c), it is possible to apply to an illumination of a type that irradiates an arbitrary part at a desired timing. Become.
(第3実施形態)
第3実施形態は、第2実施形態における位相変調領域と第2面側電極の一次元配置を、二次元配置に変更した実施形態である。換言すれば、この第2実施形態は、第1実施形態のような複数の発光部の一次元配置を二次元配置に変更した実施形態であり、そのように変更した点以外は第2実施形態と同様である。 (Third embodiment)
The third embodiment is an embodiment in which the one-dimensional arrangement of the phase modulation region and the second surface side electrode in the second embodiment is changed to a two-dimensional arrangement. In other words, the second embodiment is an embodiment in which the one-dimensional arrangement of the plurality of light emitting units is changed to a two-dimensional arrangement as in the first embodiment. Except for such a change, the second embodiment. It is the same.
第3実施形態は、第2実施形態における位相変調領域と第2面側電極の一次元配置を、二次元配置に変更した実施形態である。換言すれば、この第2実施形態は、第1実施形態のような複数の発光部の一次元配置を二次元配置に変更した実施形態であり、そのように変更した点以外は第2実施形態と同様である。 (Third embodiment)
The third embodiment is an embodiment in which the one-dimensional arrangement of the phase modulation region and the second surface side electrode in the second embodiment is changed to a two-dimensional arrangement. In other words, the second embodiment is an embodiment in which the one-dimensional arrangement of the plurality of light emitting units is changed to a two-dimensional arrangement as in the first embodiment. Except for such a change, the second embodiment. It is the same.
図15~図17を参照して、第3実施形態に係る半導体発光素子300の構成を説明する。図15は、第3実施形態に係る半導体発光素子300を第1面側から見た図、図16は、半導体発光素子300を第2面側から見た図、図17は、図15および図16のXVI-XVI線に沿っての断面図である。図15~図17には15個の発光部(第1発光部~第15発光部)が3行5列に並んでいる例が示されているが、発光部の数は15以外であってもよく、また、二次元の配置は任意でよい。
With reference to FIGS. 15 to 17, the structure of the semiconductor light emitting device 300 according to the third embodiment will be described. 15 is a diagram of the semiconductor light emitting device 300 according to the third embodiment as viewed from the first surface side, FIG. 16 is a diagram of the semiconductor light emitting device 300 as viewed from the second surface side, and FIG. FIG. 16 is a sectional view taken along line XVI-XVI. 15 to 17 show an example in which 15 light emitting units (first light emitting unit to 15th light emitting unit) are arranged in 3 rows and 5 columns, but the number of light emitting units is other than 15. The two-dimensional arrangement may be arbitrary.
図15~図17に示されたように、半導体発光素子300は、第1面300aと第2面300bとを有し、光出射面として第1面300aから光を出力する。なお、本実施形態において、第2面300bはサポート面として機能する。半導体発光素子300は、共通基板層301と、活性層303と、位相変調層304と、第1クラッド層302と、第2クラッド層306と、複数の第2面側電極308-1~308-15と、第1面側電極310と、を備える。位相変調層304は、活性層303と光学的に結合される複数の位相変調領域304-1~304-15を有する。なお、少なくとも、活性層303と複数の位相変調領域304-1~304-15を含む位相変調層304により積層構造体が構成されている。第1クラッド層302は、積層構造体(少なくとも、活性層303と位相変調層304を含む)に対して第1面300aが配置された側に位置する。第2クラッド層306は、積層構造体(少なくとも、活性層303と位相変調層304を含む)の第2面300bが配置された側に位置する。第2面側電極308-1~308-15は、第2クラッド層306に対して第2面300bが配置された側であって、位相変調領域304-1~304-15それぞれに対応する位置に配置されている。第1面側電極310は、第1クラッド層302に対して第1面300aが配置された側に位置する。
15 to 17, the semiconductor light emitting device 300 has a first surface 300a and a second surface 300b, and outputs light from the first surface 300a as a light emitting surface. In the present embodiment, the second surface 300b functions as a support surface. The semiconductor light emitting device 300 includes a common substrate layer 301, an active layer 303, a phase modulation layer 304, a first cladding layer 302, a second cladding layer 306, and a plurality of second surface side electrodes 308-1 to 308-. 15 and a first surface side electrode 310. The phase modulation layer 304 includes a plurality of phase modulation regions 304-1 to 304-15 that are optically coupled to the active layer 303. Note that a laminated structure is constituted by at least the active layer 303 and the phase modulation layer 304 including the plurality of phase modulation regions 304-1 to 304-15. The first cladding layer 302 is located on the side where the first surface 300a is disposed with respect to the laminated structure (including at least the active layer 303 and the phase modulation layer 304). The second cladding layer 306 is located on the side where the second surface 300b of the laminated structure (including at least the active layer 303 and the phase modulation layer 304) is disposed. The second surface side electrodes 308-1 to 308-15 are on the side where the second surface 300b is disposed with respect to the second cladding layer 306, and positions corresponding to the phase modulation regions 304-1 to 304-15, respectively. Is arranged. The first surface side electrode 310 is located on the side where the first surface 300 a is disposed with respect to the first cladding layer 302.
位相変調領域304-1~304-15は、それぞれ、第1屈折率を有する基本領域304-1a~304-15aと第1屈折率とは異なる第2屈折率を有する複数の異屈折率領域304-1b~304-15bを含む。複数の異屈折率領域304-1b~304-15bは、それぞれの重心G1が基本領域304-1a~304-15a中の仮想的な正方格子における各格子点Oから所定の距離rだけずれた場所に位置するような配置パターンに従って基本領域304-1a~304-15a中に配置される。位相変調領域304-1~304-15のそれぞれにおける異屈折率領域304-1b~304-15bの配置パターンは、当該位相変調領域304-1~304-15に対応する第2面側電極308-1~308-15から駆動電流が供給されたときに第1面300aから出力される光で表現されるビーム投射パターンと該ビーム投射パターンの投射範囲であるビーム投射領域が、目標ビーム投射パターンと目標ビーム投射領域に一致するよう設定されている。
The phase modulation regions 304-1 to 304-15 each include a plurality of different refractive index regions 304 having a second refractive index different from the basic regions 304-1a to 304-15a having the first refractive index. -1b to 304-15b. The plurality of different refractive index regions 304-1b to 304-15b are locations where the center of gravity G1 is shifted from each lattice point O in the virtual square lattice in the basic regions 304-1a to 304-15a by a predetermined distance r. Are arranged in the basic areas 304-1a to 304-15a according to the arrangement pattern as shown in FIG. The arrangement pattern of the different refractive index regions 304-1b to 304-15b in each of the phase modulation regions 304-1 to 304-15 is the second surface side electrode 308- corresponding to the phase modulation regions 304-1 to 304-15. A beam projection pattern expressed by light output from the first surface 300a when a drive current is supplied from 1 to 308-15 and a beam projection area that is a projection range of the beam projection pattern are a target beam projection pattern and It is set to coincide with the target beam projection area.
第2面側電極308-1~308-15から駆動電流が供給されたときに出力される光のビーム投射領域は、全てが同じであってもよいし、少なくとも一部が他と異なっていてもよい。また、第2面側電極308-1~308-15から駆動電流が供給されたときに出力される光のビーム投射パターンも、全てが同じであってもよいし、少なくとも一部が他と異なっていてもよい。
The beam projection areas of the light output when the drive current is supplied from the second surface side electrodes 308-1 to 308-15 may all be the same, or at least part of them may be different from the others. Also good. Also, the beam projection pattern of the light output when the drive current is supplied from the second surface side electrodes 308-1 to 308-15 may be all the same, or at least partly different from the others. It may be.
活性層303、位相変調層304、第1クラッド層302、第2クラッド層306、および共通基板層301には、第2面300bから共通基板層301に向かって、該共通基板層301に到達するまで伸びた分離領域312が設けられている。分離領域312は、Z軸方向(積層方向)から見たときに位相変調領域304-1~204-5と重なる、活性層303、第1クラッド層302、第2クラッド層306、第1クラッド層302、および第2クラッド層306それぞれにおける対応領域間を電気的および光学的に分離するよう、第2面300bから共通基板層301に向かって伸びている。共通基板層301のうち、分離領域312の下部に位置する部分の厚さ(分離領域312の第1面側電極310側の端面312aと第1面側電極310の間の最短距離)は、Z軸方向に沿った共通基板層201の厚さの半分以下であり、典型的には70μm以下である。図17に示されたように、分離領域312の位置で区切られる半導体発光素子300の各部分は、それぞれ独立した発光部(第1発光部~第15発光部)と看做すことができる。また、分離領域312の製造工程は、第1実施形態と同様である。
The active layer 303, the phase modulation layer 304, the first cladding layer 302, the second cladding layer 306, and the common substrate layer 301 reach the common substrate layer 301 from the second surface 300b toward the common substrate layer 301. A separation region 312 extending up to is provided. The isolation region 312 is an active layer 303, a first cladding layer 302, a second cladding layer 306, and a first cladding layer that overlap with the phase modulation regions 304-1 to 204-5 when viewed from the Z-axis direction (stacking direction). 302 and the second cladding layer 306 respectively extend from the second surface 300b toward the common substrate layer 301 so as to electrically and optically separate corresponding regions. The thickness of the portion of the common substrate layer 301 located below the isolation region 312 (the shortest distance between the end surface 312a of the isolation region 312 on the first surface side electrode 310 side and the first surface side electrode 310) is Z It is less than half of the thickness of the common substrate layer 201 along the axial direction, and typically less than 70 μm. As shown in FIG. 17, each part of the semiconductor light emitting device 300 divided by the position of the isolation region 312 can be regarded as an independent light emitting part (first light emitting part to 15th light emitting part). The manufacturing process of the separation region 312 is the same as that in the first embodiment.
第1面側電極310は、図15および図17に示されたように、位相変調領域304-1~304-15と第2面側電極308-1~308-15に対応する位置に開口部310-1~310-15を有している。第1面側電極310は、開口部を有する電極の代わりに、透明電極であってもよい。
As shown in FIGS. 15 and 17, the first surface side electrode 310 has openings at positions corresponding to the phase modulation regions 304-1 to 304-15 and the second surface side electrodes 308-1 to 308-15. 310-1 to 310-15. The first surface side electrode 310 may be a transparent electrode instead of the electrode having the opening.
活性層303と位相変調層304の上下関係は、図17に示された上下関係と逆であってもよい。また、図17には、共通基板層301、上部光ガイド層305b、下部光ガイド層305a、コンタクト層307、絶縁層309、反射防止層311も記載されているが、半導体発光素子200は、必ずしもこれらを備えている必要はない。
The vertical relationship between the active layer 303 and the phase modulation layer 304 may be opposite to the vertical relationship shown in FIG. FIG. 17 also shows the common substrate layer 301, the upper light guide layer 305b, the lower light guide layer 305a, the contact layer 307, the insulating layer 309, and the antireflection layer 311. It is not necessary to have these.
これまでに説明した各層、各領域の構成材料、形状、寸法、分離領域の製造工程を除く主要工程を含む製造方法等は、第1実施形態、第2実施形態と同様に、特許文献1の記載内容に基づいて当業者が適宜選択可能であるが、以下にその一部の例を示す。すなわち、図17に示された各層の材料ないし構造の一例は、次のとおりである。共通基板層301はGaAsからなる。第1クラッド層302はAlGaAsからなる。活性層303は多重量子井戸構造MQW(障壁層:AlGaAs/井戸層:InGaAs)を有する。位相変調層304は、基本領域304-1a~304-15aと、該基本領域304-1a~304-15a内に埋め込まれた複数の異屈折率領域304-1b~304-15を含む。基本領域304-1a~304-15aはGaAsからなる。複数の異屈折率領域304-1b~304-15bがAlGaAsからなる。上部光ガイド層305bと下部光ガイド層305aはAlGaAsからなる。第2クラッド層306はAlGaAsからなる。コンタクト層307はGaAsからなる。絶縁層309はSiO2またはシリコン窒化物からなる。反射防止層311は、窒化シリコン(SiN)、二酸化シリコン(SiO2)などの誘電体単層膜或いは誘電体多層膜からなる。分離領域312は高強度光(電場)により改質された半導体層、不純物拡散およびイオン打ち込み法の何れかにより絶縁化された半導体層、または、ドライエッチングまたはウェットエッチングにより形成されたスリット(空隙)である。ここで、高強度光(電場)による改質の具体的手法としては、例えば、ナノ秒レーザによる加工や超短パルスレーザによる加工がある。複数の異屈折率領域304-1b~304-15bは、アルゴン、窒素または空気等が封入された空孔であってもよい。
The manufacturing method including the main processes excluding the manufacturing process of each layer, each region, the region, and the separation region described so far are the same as those in the first embodiment and the second embodiment. A person skilled in the art can select as appropriate based on the description, but some examples are shown below. That is, an example of the material or structure of each layer shown in FIG. 17 is as follows. The common substrate layer 301 is made of GaAs. The first cladding layer 302 is made of AlGaAs. The active layer 303 has a multiple quantum well structure MQW (barrier layer: AlGaAs / well layer: InGaAs). The phase modulation layer 304 includes basic regions 304-1a to 304-15a and a plurality of different refractive index regions 304-1b to 304-15 embedded in the basic regions 304-1a to 304-15a. The basic regions 304-1a to 304-15a are made of GaAs. The plurality of different refractive index regions 304-1b to 304-15b are made of AlGaAs. The upper light guide layer 305b and the lower light guide layer 305a are made of AlGaAs. The second cladding layer 306 is made of AlGaAs. The contact layer 307 is made of GaAs. The insulating layer 309 is made of SiO 2 or silicon nitride. The antireflection layer 311 is made of a dielectric single layer film or a dielectric multilayer film such as silicon nitride (SiN) or silicon dioxide (SiO 2 ). The isolation region 312 is a semiconductor layer modified by high-intensity light (electric field), a semiconductor layer insulated by one of impurity diffusion and ion implantation, or a slit (gap) formed by dry etching or wet etching. It is. Here, as a specific method of modification by high intensity light (electric field), there are, for example, processing by a nanosecond laser and processing by an ultrashort pulse laser. The plurality of different refractive index regions 304-1b to 304-15b may be holes filled with argon, nitrogen, air, or the like.
一例では、共通基板層301と第1クラッド層302には、N型の不純物が添加されている。第2クラッド層306とコンタクト層307には、P型の不純物が添加されている。また、第1クラッド層302と第2クラッド層306のエネルギーバンドギャップは、上部光ガイド層305bと下部光ガイド層305aのエネルギーバンドギャップよりも大きい。上部光ガイド層305bと下部光ガイド層305aのエネルギーバンドギャップは、活性層303の多重量子井戸構造MQWのエネルギーバンドギャップよりも大きく設定されている。
For example, an N-type impurity is added to the common substrate layer 301 and the first cladding layer 302. P-type impurities are added to the second cladding layer 306 and the contact layer 307. The energy band gap between the first cladding layer 302 and the second cladding layer 306 is larger than the energy band gap between the upper light guide layer 305b and the lower light guide layer 305a. The energy band gap between the upper light guide layer 305 b and the lower light guide layer 305 a is set to be larger than the energy band gap of the multiple quantum well structure MQW of the active layer 303.
次に、図18を参照して、半導体発光素子300を備える発光装置の構成を説明する。図18は半導体発光素子300を備える発光装置の構成を示すブロック図である。
Next, with reference to FIG. 18, a configuration of a light emitting device including the semiconductor light emitting element 300 will be described. FIG. 18 is a block diagram illustrating a configuration of a light emitting device including the semiconductor light emitting element 300.
図18に示されたように、発光装置340は、半導体発光素子300と、電源回路341と、制御信号入力回路342と、駆動回路343と、を備える。電源回路341は、駆動回路343と半導体発光素子300に電源を供給する。制御信号入力回路342は、発光装置340の外部から供給される制御信号を駆動回路343へ伝達する。駆動回路343は、半導体発光素子300に駆動電流を供給する。駆動回路343と半導体発光素子300とは、駆動電流を供給する複数の駆動ライン344-1~344-15と1本の共通電位ライン345により接続されている。駆動ライン344-1~344-15は、第2面側電極308-1~308-15のそれぞれに接続され、共通電位ライン345は第1面側電極310に接続されている。なお、図18において、駆動回路343の上に示された半導体発光素子300と駆動回路343の下に示された半導体発光素子300は、それぞれ、1つの半導体発光素子300の第1面と第2面を表している。
As shown in FIG. 18, the light emitting device 340 includes a semiconductor light emitting element 300, a power supply circuit 341, a control signal input circuit 342, and a drive circuit 343. The power supply circuit 341 supplies power to the drive circuit 343 and the semiconductor light emitting element 300. The control signal input circuit 342 transmits a control signal supplied from the outside of the light emitting device 340 to the drive circuit 343. The drive circuit 343 supplies a drive current to the semiconductor light emitting element 300. The drive circuit 343 and the semiconductor light emitting element 300 are connected by a plurality of drive lines 344-1 to 344-15 for supplying a drive current and one common potential line 345. The drive lines 344-1 to 344-15 are connected to the second surface side electrodes 308-1 to 308-15, respectively, and the common potential line 345 is connected to the first surface side electrode 310. In FIG. 18, the semiconductor light emitting device 300 shown above the drive circuit 343 and the semiconductor light emitting device 300 shown below the drive circuit 343 are respectively the first surface and the second surface of one semiconductor light emitting device 300. Represents a surface.
駆動ライン344-1~344-15は、用途に応じて、択一的に駆動されてもよいし、少なくとも2本が同時に駆動されてもよい。また、駆動回路343は、半導体発光素子300とは別体で構成されてもよいし、半導体発光素子300の共通基板層301上に一体的に形成されてもよい。
The drive lines 344-1 to 344-15 may be driven alternatively according to the application, or at least two may be driven simultaneously. In addition, the drive circuit 343 may be configured separately from the semiconductor light emitting element 300 or may be integrally formed on the common substrate layer 301 of the semiconductor light emitting element 300.
以上のように構成された半導体発光素子300を備える発光装置340は、次のように動作する。すなわち、駆動回路343から駆動ライン344-1~344-15の何れかと共通電位ライン345の間に駆動電流が供給される。駆動電流が供給された駆動ラインに接続された第2面側電極に対応する発光部では、活性層303において電子と正孔の再結合が生じ、その発光部における活性層303が発光する。その発光により得られた光は、第1クラッド層302と第2クラッド層306によって効率的に閉じ込められる。活性層303から出射された光は、対応する位相変調領域の内部に入射し、位相変調領域による2次元的なフィードバックによる閉じ込め効果によって所定のモードを形成する。活性層に十分な電子と正孔を注入することによって、位相変調領域に入射した光は所定のモードで発振する。所定の発振モードを形成した光は、異屈折率領域の配置パターンに応じた位相変調を受け、位相変調を受けた光が、配置パターン応じたビーム投射領域とビーム投射パターンを有する光として第1面側電極側から外部に出射される。
The light emitting device 340 including the semiconductor light emitting element 300 configured as described above operates as follows. That is, a drive current is supplied from the drive circuit 343 between any of the drive lines 344-1 to 344-15 and the common potential line 345. In the light emitting portion corresponding to the second surface side electrode connected to the driving line supplied with the driving current, recombination of electrons and holes occurs in the active layer 303, and the active layer 303 in the light emitting portion emits light. The light obtained by the light emission is efficiently confined by the first cladding layer 302 and the second cladding layer 306. The light emitted from the active layer 303 enters the corresponding phase modulation region, and forms a predetermined mode by the confinement effect by two-dimensional feedback by the phase modulation region. By injecting sufficient electrons and holes into the active layer, the light incident on the phase modulation region oscillates in a predetermined mode. The light that has formed a predetermined oscillation mode undergoes phase modulation according to the arrangement pattern of the different refractive index regions, and the light subjected to the phase modulation is first as light having a beam projection region and a beam projection pattern according to the arrangement pattern. The light is emitted from the surface side electrode side to the outside.
本実施形態においても、半導体発光素子300が複数の位相変調領域304-1~304-15を有する位相変調層304を備えた単一の素子である。そのため、それぞれ一つの位相変調領域(位相変調層)を備える複数の半導体発光素子が支持基板上に配置されている構成とは違い、複数の半導体発光素子が支持基板上に配置される過程が必要とされない。そのため、目標ビーム投射領域への目標ビーム投射パターンの光の照射が容易かつ高精度に実現される。
Also in this embodiment, the semiconductor light emitting device 300 is a single device including the phase modulation layer 304 having a plurality of phase modulation regions 304-1 to 304-15. Therefore, unlike a configuration in which a plurality of semiconductor light emitting elements each having one phase modulation region (phase modulation layer) are arranged on the support substrate, a process in which the plurality of semiconductor light emitting elements are arranged on the support substrate is necessary. And not. Therefore, the irradiation of the light of the target beam projection pattern to the target beam projection area can be realized easily and with high accuracy.
本実施形態においても、活性層303、位相変調層304、第1クラッド層302、第2クラッド層306、および共通基板層301に、第2面300bから共通基板層301に向かって、該共通基板層301に到達するまで伸びた分離領域312が設けられている。隣接する位相変調領域304-1~304-15は、このような分離領域312によって電気的および光学的に分離されるので、隣接する位相変調領域304-1~304-15間でのクロストークの発生が抑制される。この結果、所望のビーム投射領域への所望のビーム投射パターンの光の照射が、より一層高精度で実現される。
Also in the present embodiment, the active substrate 303, the phase modulation layer 304, the first cladding layer 302, the second cladding layer 306, and the common substrate layer 301 are formed from the second surface 300 b toward the common substrate layer 301. A separation region 312 is provided that extends until it reaches the layer 301. Since the adjacent phase modulation regions 304-1 to 304-15 are electrically and optically separated by such a separation region 312, crosstalk between the adjacent phase modulation regions 304-1 to 304-15 is reduced. Occurrence is suppressed. As a result, irradiation of the light of the desired beam projection pattern to the desired beam projection region is realized with higher accuracy.
本実施形態においても、第2面側電極308-1~308-15の何れから駆動電流が供給された場合にもビーム投射領域が等しくなるように、位相変調領域304-1~304-15のそれぞれにおける配置パターンが定められていてもよい。このような構成の場合、特許文献1に示された半導体発光素子の応用例(レーザビームを対象物に対して走査するようにした応用例)以外への各種の応用が可能となる。可能な応用は、第2実施形態と同様である。
Also in this embodiment, the phase modulation areas 304-1 to 304-15 are set so that the beam projection areas are equal even when the drive current is supplied from any of the second surface side electrodes 308-1 to 308-15. The arrangement pattern in each may be defined. In the case of such a configuration, various applications other than the application example (application example in which a laser beam is scanned with respect to an object) of the semiconductor light emitting element disclosed in Patent Document 1 are possible. Possible applications are the same as in the second embodiment.
また、本実施形態においても、第2面側電極308-1~308-15の何れから駆動電流が供給された場合にもビーム投射パターンが等しくなるように、位相変調領域304-1~304-15のそれぞれにおける配置パターンが設定されてもよい。このような構成の場合、特許文献1に示された半導体発光素子の応用例(レーザビームを対象物に対して走査するようにした応用例)と同様の応用が可能となる他、それとは異なる各種の応用も可能となる。この場合に可能な応用も、第2実施形態と同様である。
Also in the present embodiment, the phase modulation regions 304-1 to 304- are set so that the beam projection patterns are equal even when the drive current is supplied from any of the second surface side electrodes 308-1 to 308-15. The arrangement pattern in each of 15 may be set. In the case of such a configuration, an application similar to the application example of the semiconductor light emitting device disclosed in Patent Document 1 (application example in which the laser beam is scanned with respect to the object) is possible, and is different from that. Various applications are also possible. Possible applications in this case are the same as in the second embodiment.
(第4実施形態)
第4実施形態は、第1実施形態では第1面側から取り出していた光出力を第2面側から取り出すように変更したものである。これによれば、光出力が共通基板層を通過しないため共通基板層による出力光の吸収をなくすことが出来、出力光の減衰や共通基板層の発熱を防止することが出来る。そのように変更した点以外は第1実施形態と同様である。 (Fourth embodiment)
In the fourth embodiment, the light output extracted from the first surface side in the first embodiment is changed to be extracted from the second surface side. According to this, since the light output does not pass through the common substrate layer, the absorption of the output light by the common substrate layer can be eliminated, and the attenuation of the output light and the heat generation of the common substrate layer can be prevented. Except for such a change, the second embodiment is the same as the first embodiment.
第4実施形態は、第1実施形態では第1面側から取り出していた光出力を第2面側から取り出すように変更したものである。これによれば、光出力が共通基板層を通過しないため共通基板層による出力光の吸収をなくすことが出来、出力光の減衰や共通基板層の発熱を防止することが出来る。そのように変更した点以外は第1実施形態と同様である。 (Fourth embodiment)
In the fourth embodiment, the light output extracted from the first surface side in the first embodiment is changed to be extracted from the second surface side. According to this, since the light output does not pass through the common substrate layer, the absorption of the output light by the common substrate layer can be eliminated, and the attenuation of the output light and the heat generation of the common substrate layer can be prevented. Except for such a change, the second embodiment is the same as the first embodiment.
図19~図21を参照して、第4実施形態に係る半導体発光素子100Bの構成を説明する。図19は、第4実施形態に係る半導体発光素子100Bを第1面側から見た図である。図20は、半導体発光素子100Bを第2面側から見た図である。図21は、図19および図20のXX-XX線に沿っての断面図である。
The configuration of the semiconductor light emitting device 100B according to the fourth embodiment will be described with reference to FIGS. FIG. 19 is a view of the semiconductor light emitting device 100B according to the fourth embodiment as viewed from the first surface side. FIG. 20 is a view of the semiconductor light emitting device 100B as viewed from the second surface side. FIG. 21 is a sectional view taken along line XX-XX in FIGS.
図19~図21に示されたように、半導体発光素子100Bは、第1面100Baと第2面100Bbとを有し、第1~第3実施形態とは異なり、光出射面として第2面100Bbから光を出力する。なお、本実施形態において、第1面100Baはサポート面として機能する。半導体発光素子100Bは、共通基板層101Bと、活性層103Bと、位相変調層104Bと、第1クラッド層102Bと、第2クラッド層106Bと、一対の第2面側電極108B-1、108B-2と、一対の第1面側電極110B-1、110B-2と、を備える。位相変調層104Bは、活性層103Bと光学的に結合される一対の位相変調領域104B-1、104B-2を有する。なお、少なくとも、活性層103Bと一対の位相変調領域104B-1、104B-2を含む位相変調層104Bにより積層構造体が構成されている。第1クラッド層102Bは、積層構造体(少なくとも、活性層103Bと位相変調層104Bを含む)に対して第1面100Baが配置された側に位置する。第2クラッド層106Bは、積層構造(少なくとも、活性層103Bと位相変調層104Bを含む)に対して第2面100Bbが配置された側に位置する。第2面側電極108B-1、108B-2は、第2クラッド層106Bに対して第2面100Bbが配置された側であって、位相変調領域104B-1、104B-2それぞれに対応する位置に配置されている。第1面側電極110B-1、110B-2は、第1クラッド層102に対して第1面100Baが配置された側に位置する。
As shown in FIGS. 19 to 21, the semiconductor light emitting device 100B has a first surface 100Ba and a second surface 100Bb, and unlike the first to third embodiments, the second surface as a light emitting surface. Light is output from 100 Bb. In the present embodiment, the first surface 100Ba functions as a support surface. The semiconductor light emitting device 100B includes a common substrate layer 101B, an active layer 103B, a phase modulation layer 104B, a first cladding layer 102B, a second cladding layer 106B, and a pair of second surface side electrodes 108B-1 and 108B-. 2 and a pair of first surface side electrodes 110B-1 and 110B-2. The phase modulation layer 104B has a pair of phase modulation regions 104B-1 and 104B-2 that are optically coupled to the active layer 103B. Note that a laminated structure is constituted by at least the phase modulation layer 104B including the active layer 103B and the pair of phase modulation regions 104B-1 and 104B-2. The first cladding layer 102B is located on the side where the first surface 100Ba is disposed with respect to the stacked structure (including at least the active layer 103B and the phase modulation layer 104B). The second cladding layer 106B is located on the side where the second surface 100Bb is disposed with respect to the laminated structure (including at least the active layer 103B and the phase modulation layer 104B). The second surface side electrodes 108B-1 and 108B-2 are on the side where the second surface 100Bb is disposed with respect to the second cladding layer 106B, and positions corresponding to the phase modulation regions 104B-1 and 104B-2, respectively. Is arranged. The first surface side electrodes 110B-1 and 110B-2 are located on the side where the first surface 100Ba is disposed with respect to the first cladding layer 102.
位相変調領域104B-1、104B-2それぞれは、第1屈折率を有する基本領域104B-1a、104B-1bと第1屈折率とは異なる第2屈折率を有する複数の異屈折率領域104B-2a、104B-2bとを有する。複数の異屈折率領域104B-1b、104B-2bは、それぞれの重心G1が基本領域104B-1a、104-2a中の仮想的な正方格子における各格子点Oから所定の距離rだけずれた場所に位置するような配置パターンに従って基本領域104B-1a,104B-2a中に配置される。位相変調領域104B-1、104B-2それぞれにおける複数の異屈折率領域104B-1b、104B-2bの配置パターンは、当該位相変調領域104B-1または104B-2に対応する第2面側電極108B-1または108B-2から駆動電流が供給されたときに第2面100Bbから出力される光で表現されるビーム投射パターンと該ビーム投射パターンの投射範囲であるビーム投射領域が、目標ビーム投射パターンと目標ビーム投射領域に一致するように設定されている。
Each of the phase modulation regions 104B-1 and 104B-2 includes a plurality of different refractive index regions 104B- having a second refractive index different from the basic regions 104B-1a and 104B-1b having the first refractive index. 2a, 104B-2b. The plurality of different refractive index regions 104B-1b and 104B-2b are locations where the center of gravity G1 is shifted from each lattice point O in the virtual square lattice in the basic regions 104B-1a and 104-2a by a predetermined distance r. Are arranged in the basic areas 104B-1a and 104B-2a according to the arrangement pattern as shown in FIG. The arrangement pattern of the plurality of different refractive index regions 104B-1b and 104B-2b in each of the phase modulation regions 104B-1 and 104B-2 is the second surface side electrode 108B corresponding to the phase modulation region 104B-1 or 104B-2. -1 or 108B-2 when a drive current is supplied, a beam projection pattern expressed by light output from the second surface 100Bb and a beam projection area that is a projection range of the beam projection pattern are a target beam projection pattern And the target beam projection area.
第2面側電極108B-1から駆動電流が供給されたときに出力される光ビーム投射領域と第2面側電極108B-2から駆動電流が供給されたときに出力される光のビーム投射領域とは、同じであってもよいし異なっていてもよい。また、第2面側電極108B-1から駆動電流が供給されたときに出力される光のビーム投射パターンと第2面側電極108B-2から駆動電流が供給されたときに出力されるビーム投射パターンも、同じであってもよいし異なっていてもよい。
A light beam projection region output when a drive current is supplied from the second surface side electrode 108B-1 and a light beam projection region output when a drive current is supplied from the second surface side electrode 108B-2. And may be the same or different. Further, a beam projection pattern of light output when a drive current is supplied from the second surface side electrode 108B-1 and a beam projection pattern output when a drive current is supplied from the second surface side electrode 108B-2. The patterns may be the same or different.
活性層103B、位相変調層104B、第1クラッド層102B、第2クラッド層106B、および共通基板層101Bには、第2面100Bbから共通基板層101Bに向かって、該共通基板層101Bに到達するまで伸びた分離領域112Bが設けられている。分離領域112Bは、Z軸方向(積層方向)から見たときに位相変調領域104B-1、104B-2と重なる、活性層103B、第1クラッド層102B、第2クラッド層106B、第1クラッド層102B、および第2クラッド層106Bそれぞれにおける対応領域間を電気的および光学的に分離するよう、第2面100Bbから共通基板層101Bに向かって伸びている。共通基板層101Bのうち、分離領域112Bの下部に位置する部分の厚さ(分離領域112Bの第1面側電極110B-1、110B-2側の端面112Baと第1面側電極110B-1、110B-2の間の距離)は、Z軸方向(積層方向)に沿った共通基板層101Bの厚さの半分以下であり、典型的には70μm以下である。なお、この第4実施形態では、第1面側電極が2つに分かれているが、これら2つの第1面側電極110B-1、110B-2を併せて「第1面側電極」と指す。したがって、「分離領域112Bの第1面側電極110B-1、110B-2側の端面112Baと第1面側電極110B-1、110B-2の間の距離」(共通基板層101Bにおける分離領域の未形成部分の厚さ)は、第1面側電極110B-1と第1面側電極、110B-2の双方の、共通基板層101Bが配置された側の面を含む1つの平面と、端面112Baとの間の距離を指す。このように規定される分離領域112Bの端面112Baから第1面側電極110B-1、110B-2までの距離(最小間隔)、共通基板層101Bの、Z軸方向(積層方向)に沿った厚みの半分以下である。また、このような分離領域の未形成部分の厚さは、典型的には、70μm以下である。図21に示されたように、分離領域112Bの位置で区切られる半導体発光素子100Bの各部分は、それぞれ独立した発光部(第1発光部、第2発光部)と看做すことができる。また、分離領域112Bの製造工程は、第1実施形態と同様である。
The active layer 103B, the phase modulation layer 104B, the first cladding layer 102B, the second cladding layer 106B, and the common substrate layer 101B reach the common substrate layer 101B from the second surface 100Bb toward the common substrate layer 101B. A separation region 112 </ b> B extending to the top is provided. The isolation region 112B includes the active layer 103B, the first cladding layer 102B, the second cladding layer 106B, and the first cladding layer that overlap with the phase modulation regions 104B-1 and 104B-2 when viewed from the Z-axis direction (stacking direction). The corresponding regions in 102B and the second cladding layer 106B extend from the second surface 100Bb toward the common substrate layer 101B so as to electrically and optically separate the corresponding regions. The thickness of the portion of the common substrate layer 101B located below the isolation region 112B (the end surface 112Ba on the first surface side electrode 110B-1, 110B-2 side of the isolation region 112B and the first surface side electrode 110B-1, 110B-2) is equal to or less than half the thickness of the common substrate layer 101B along the Z-axis direction (stacking direction), and typically equal to or less than 70 μm. In the fourth embodiment, the first surface side electrode is divided into two. The two first surface side electrodes 110B-1 and 110B-2 are collectively referred to as a “first surface side electrode”. . Therefore, “the distance between the end surface 112Ba on the first surface side electrodes 110B-1 and 110B-2 side of the separation region 112B and the first surface side electrodes 110B-1 and 110B-2” (the separation region of the common substrate layer 101B). The thickness of the unformed portion is defined as one flat surface including the surface on which the common substrate layer 101B is disposed on both the first surface side electrode 110B-1 and the first surface side electrode 110B-2, and the end surface. Refers to the distance to 112Ba. The distance (minimum distance) from the end surface 112Ba of the separation region 112B to the first surface side electrodes 110B-1 and 110B-2 and the thickness of the common substrate layer 101B along the Z-axis direction (stacking direction). Less than half. In addition, the thickness of the unformed part of such a separation region is typically 70 μm or less. As shown in FIG. 21, each part of the semiconductor light emitting device 100B divided by the position of the isolation region 112B can be regarded as an independent light emitting part (first light emitting part, second light emitting part). The manufacturing process of the separation region 112B is the same as that of the first embodiment.
第2面側電極108B-1、108B-2は、図20および図21に示されたように、位相変調領域104B-1、104B-2と第1面側電極110B-1、110B-2に対応する位置に開口部108B-1a、108B-2aを有している。第2面側電極108B-1、108B-2は、開口部を有する電極の代わりに、透明電極であってもよい。
As shown in FIGS. 20 and 21, the second surface side electrodes 108B-1 and 108B-2 are connected to the phase modulation regions 104B-1 and 104B-2 and the first surface side electrodes 110B-1 and 110B-2. Openings 108B-1a and 108B-2a are provided at corresponding positions. The second surface side electrodes 108B-1 and 108B-2 may be transparent electrodes instead of the electrodes having openings.
活性層103Bと位相変調層104Bの上下関係は、図21に示された上下関係と逆であってもよい。また、共通基板層101Bでの光の吸収を低減する目的で共通基板層101Bと第1クラッド層102Bの間にDBR層120Bがあっても良い。DBR層120Bは位相変調層104Bと共通基板層101Bの間であればこれ以外の場所にあっても良い。また、図21には、共通基板層101B、上部光ガイド層105Bb、下部光ガイド層105Ba、コンタクト層107B、絶縁層109、反射防止層111Bも記載されているが、半導体発光素子100Bは、必ずしもこれらを備えている必要はない。
The vertical relationship between the active layer 103B and the phase modulation layer 104B may be opposite to the vertical relationship shown in FIG. Further, there may be a DBR layer 120B between the common substrate layer 101B and the first cladding layer 102B for the purpose of reducing light absorption in the common substrate layer 101B. The DBR layer 120B may be located at other locations as long as it is between the phase modulation layer 104B and the common substrate layer 101B. FIG. 21 also shows the common substrate layer 101B, the upper light guide layer 105Bb, the lower light guide layer 105Ba, the contact layer 107B, the insulating layer 109, and the antireflection layer 111B. It is not necessary to have these.
これまでに説明した各層、各領域の構成材料、形状、寸法、分離領域の製造工程を除く主要工程を含む製造方法等は、特許文献1の記載内容に基づいて当業者が適宜選択可能であるが、以下にその一部の例を示す。すなわち、図21に示された各層の材料ないし構造の一例は、次のとおりである。共通基板層101BはGaAsからなる。第1クラッド層102BはAlGaAsからなる。活性層103Bは多重量子井戸構造MQW(障壁層:AlGaAs/井戸層:InGaAs)を有する。位相変調層104Bは、基本領域104B-1a、104B-2aと、該基本領域104B-1a、104B-2a内に埋め込まれた複数の異屈折率領域104B-1b、104B-2bを含む。基本領域104B-1a、104B-2aはGaAsからなる。複数の異屈折率領域104B-1b、104B-2bがAlGaAsからなる。上部光ガイド層105Bbと下部光ガイド層105BaはAlGaAsからなる。第2クラッド層106BはAlGaAsからなる。コンタクト層107BはGaAsからなる。絶縁層109BはSiO2またはシリコン窒化物からなる。反射防止層111Bは、窒化シリコン(SiN)、二酸化シリコン(SiO2)などの誘電体単層膜或いは誘電体多層膜からなる。分離領域112Bは、高強度光(電場)により改質された半導体層、不純物拡散およびイオン打ち込み法の何れかにより絶縁化された半導体層、または、ドライエッチングおよびウェットエッチングの何れかにより形成されたスリット(空隙)である。ここで、高強度光(電場)による改質の具体的手法としては、例えば、ナノ秒レーザによる加工や超短パルスレーザによる加工がある。複数の異屈折率領域104B-1b,104B-2bは、アルゴン、窒素または空気等が封入された空孔であってもよい。
A person skilled in the art can appropriately select the manufacturing method including the main processes excluding the manufacturing process of each layer and each region described above, the constituent material, the shape, the dimensions, and the separation region. However, some examples are shown below. That is, an example of the material or structure of each layer shown in FIG. 21 is as follows. The common substrate layer 101B is made of GaAs. The first cladding layer 102B is made of AlGaAs. The active layer 103B has a multiple quantum well structure MQW (barrier layer: AlGaAs / well layer: InGaAs). The phase modulation layer 104B includes basic regions 104B-1a and 104B-2a and a plurality of different refractive index regions 104B-1b and 104B-2b embedded in the basic regions 104B-1a and 104B-2a. The basic regions 104B-1a and 104B-2a are made of GaAs. The plurality of different refractive index regions 104B-1b and 104B-2b are made of AlGaAs. The upper light guide layer 105Bb and the lower light guide layer 105Ba are made of AlGaAs. The second cladding layer 106B is made of AlGaAs. The contact layer 107B is made of GaAs. The insulating layer 109B is made of SiO 2 or silicon nitride. The antireflection layer 111B is made of a dielectric single layer film or a dielectric multilayer film such as silicon nitride (SiN) or silicon dioxide (SiO 2 ). The isolation region 112B is formed by a semiconductor layer modified by high-intensity light (electric field), a semiconductor layer insulated by any of impurity diffusion and ion implantation, or any of dry etching and wet etching It is a slit (gap). Here, as a specific method of modification by high intensity light (electric field), there are, for example, processing by a nanosecond laser and processing by an ultrashort pulse laser. The plurality of different refractive index regions 104B-1b and 104B-2b may be holes filled with argon, nitrogen, air, or the like.
一例では、共通基板層101Bと第1クラッド層102Bには、N型の不純物が添加されている。第2クラッド層106Bとコンタクト層107Bには、P型の不純物が添加されている。また、第1クラッド層102Bと第2クラッド層106Bのエネルギーバンドギャップは、上部光ガイド層105Bbと下部光ガイド層105Baのエネルギーバンドギャップよりも大きい。上部光ガイド層105Bbと下部光ガイド層105Baのエネルギーバンドギャップは、活性層103Bの多重量子井戸構造MQWのエネルギーバンドギャップよりも大きく設定されている。
In one example, N-type impurities are added to the common substrate layer 101B and the first cladding layer 102B. A P-type impurity is added to the second cladding layer 106B and the contact layer 107B. The energy band gap between the first cladding layer 102B and the second cladding layer 106B is larger than the energy band gap between the upper light guide layer 105Bb and the lower light guide layer 105Ba. The energy band gap of the upper light guide layer 105Bb and the lower light guide layer 105Ba is set to be larger than the energy band gap of the multiple quantum well structure MQW of the active layer 103B.
以上、本発明の第1~第4実施形態について説明したが、本発明は、上述した第1~第4実施形態に限定されるものではない。
The first to fourth embodiments of the present invention have been described above, but the present invention is not limited to the above-described first to fourth embodiments.
例えば、第1~第4実施形態では、分離領域112、212、312、112Bが設けられていたが、隣接する位相変調領域の間隔を広くとることができる場合等、クロストークが問題にならない場合には、分離領域は無くても良い。
For example, in the first to fourth embodiments, the separation regions 112, 212, 312, and 112B are provided. However, when the interval between adjacent phase modulation regions can be widened, crosstalk does not become a problem. May have no separation region.
例えば、図4および図5には、異屈折率領域が円形(真円)の例が示されていたが、異屈折率領域は円形以外の形状であってもよい。例えば、複数の異屈折率領域の、X-Y平面上における形状が、真円、正方形、正六角形、正八角形、正16角形、長方形、および楕円の何れかの場合、すなわち、各異屈折率領域の形状が鏡像対称(線対称)となる場合、位相変調層において、仮想的な正方格子を構成する複数の単位構成領域Rそれぞれの格子点Oから、対応するそれぞれの異屈折率領域の重心G1へ向かう方向と、X軸に平行なs軸との成す角度φを高精度に設定することが可能になる。また、複数の異屈折率領域の、X-Y平面上における形状は、図22(a)~図22(j)に示されたように、180°の回転対称性を備えない形状であってもよい。180°の回転対称性を備えない形状には、例えば、図22(b)に示された正三角形、図22(a)に示された直角二等辺三角形、図22(c)に示された二等辺三角形、2つの円または楕円の一部分が重なる、図22(i)に示された形状、図22(h)に示された卵型形状、図22(d)に示された涙型形状、図22(e)に示された矢印型形状、図22(f)に示された台形、図22(g)に示された5角形、2つの矩形の一部分が重なる、図22(j)に示された形状が含まれる。この場合、より高い光出力を得ることが可能になる。なお、卵型形状は、図22(h)に示されたように、その長軸に沿った一方の端部近傍の短軸方向の寸法が、他方の端部近傍の該短軸方向の寸法よりも小さくなるように楕円を変形することにより得られる形状である。涙型形状は、図22(d)に示されたように、その長軸に沿った楕円の一方の端部を、長軸方向に沿って突き出る尖った端部に変形することにより得られる形状である。矢印型形状は、図22(e)に示されたように、矩形の一辺が三角形の切欠き部を構成する一方、該一辺に対向する辺が三角形の突起部を構成したな形状である。
For example, although FIGS. 4 and 5 show examples in which the different refractive index region is circular (perfect circle), the different refractive index region may have a shape other than circular. For example, when the shape of the plurality of different refractive index regions on the XY plane is any one of a perfect circle, a square, a regular hexagon, a regular octagon, a regular hexagon, a rectangle, and an ellipse, that is, each different refractive index. When the shape of the region is mirror image symmetric (line symmetric), the center of gravity of each corresponding different refractive index region from the lattice point O of each of the plurality of unit constituting regions R constituting the virtual square lattice in the phase modulation layer. An angle φ formed by the direction toward G1 and the s-axis parallel to the X-axis can be set with high accuracy. Further, the shapes of the plurality of different refractive index regions on the XY plane are shapes having no rotational symmetry of 180 ° as shown in FIGS. 22 (a) to 22 (j). Also good. Examples of shapes that do not have 180 ° rotational symmetry include the equilateral triangle shown in FIG. 22B, the right isosceles triangle shown in FIG. 22A, and the shape shown in FIG. 22C. An isosceles triangle, two circles or a part of an ellipse overlap, the shape shown in FIG. 22 (i), the egg shape shown in FIG. 22 (h), and the teardrop shape shown in FIG. 22 (d) 22 (e), the trapezoid shown in FIG. 22 (f), the pentagon shown in FIG. 22 (g), and a portion of two rectangles overlap, FIG. 22 (j) The shape shown in is included. In this case, higher light output can be obtained. Note that, as shown in FIG. 22 (h), the egg-shaped shape is such that the dimension in the minor axis direction near one end along the major axis is the dimension in the minor axis direction near the other end. It is a shape obtained by deforming an ellipse so as to be smaller than that. As shown in FIG. 22D, the teardrop shape is obtained by deforming one end of an ellipse along the major axis into a sharp end projecting along the major axis. It is. As shown in FIG. 22E, the arrow shape is a shape in which one side of the rectangle forms a triangular cutout, and the side opposite to the one side forms a triangular projection.
また、第1~第3実施形態は、何れも第1面から光が出力される半導体発光素子であったが、第4実施形態のように第2面側電極を、開口を有する電極または透明電極とすることで、第2面側から光が出力される半導体発光素子としてもよい。第4実施形態においては、位相変調領域、第2面側電極、第1面側電極の数がそれぞれ2つ(一対)であったが、第2、第3実施形態と同様に、それらを3つ以上、一次元または2次元に配置するようにしてもよい。第2面側から光が出力される半導体発光素子とした場合には、光出力が共通基板層を通過しないため共通基板層による出力光の吸収をなくすことが出来、出力光の減衰や共通基板層の発熱を防止することが出来る。
In each of the first to third embodiments, the semiconductor light emitting device outputs light from the first surface. However, as in the fourth embodiment, the second surface side electrode is replaced with an electrode having an opening or a transparent By using an electrode, a semiconductor light emitting element that outputs light from the second surface side may be used. In the fourth embodiment, the number of the phase modulation region, the second surface side electrode, and the first surface side electrode is two (a pair), respectively. One or more may be arranged in one or two dimensions. In the case of a semiconductor light emitting device in which light is output from the second surface side, since the light output does not pass through the common substrate layer, the absorption of the output light by the common substrate layer can be eliminated, and the attenuation of the output light or the common substrate Heat generation of the layer can be prevented.
位相変調層には、図23に示された第1変形例のように、ビーム投射領域とビーム投射パターンを生成するための複数の異屈折率領域を含む内側領域Aと、該内側領域Aの外周を取り囲む外側領域Bが設けられてもよい。内側領域Aは、実質的には、それぞれ対応する異屈折率領域が配置された単位構成領域Rで構成された領域である。外側領域Bは、複数の周辺格子点異屈折率領域が設けられており、これら複数の周辺格子点異屈折率領域の重心は、一例として、仮想的な正方格子の外周に該仮想的な正方格子と同一の格子構造を設定することにより規定される拡張正方格子における格子点に一致していればよい。なお、図23は、位相変調層の変形例を層厚方向(Z軸方向)に沿って見た形態を示している。図23において、外側の輪郭(外側領域B)は、位相変調領域の一部を表している。外側領域Bで取り囲まれた内側領域Aは、第1~第4実施形態と同様の、ビーム投射領域とビーム投射パターンを生成するための複数の異屈折率領域を含む位相変調領域(実質的に複数の単位構成領域Rで構成された領域)である。したがって、図23の例において、位相変調層の位相変調領域は、内側領域Aと外側領域Bにより構成されている。上述のように、外側領域Bは、仮想的な正方格子における格子点位置に重心を有する複数の周辺格子点異屈折率領域を含む領域であるが、以下にその一例を示す。すなわち、外側領域Bにおける仮想的な正方格子の格子定数は内側領域Aにおける仮想的な正方格子の格子定数と等しく、外側領域Bにおける各周辺格子点異屈折率領域の形状および大きさは、内側領域Aにおける異屈折率領域の形状および大きさと等しくてもよい。この変形例によれば、面内方向への光漏れが抑制され、発振閾値電流の低減が可能になる。
In the phase modulation layer, as in the first modification shown in FIG. 23, an inner region A including a beam projection region and a plurality of different refractive index regions for generating a beam projection pattern, and the inner region A An outer region B that surrounds the outer periphery may be provided. The inner region A is substantially a region constituted by unit constitution regions R in which corresponding different refractive index regions are arranged. The outer region B is provided with a plurality of peripheral lattice point different refractive index regions, and the center of gravity of the plurality of peripheral lattice point different refractive index regions is, for example, the virtual square on the outer periphery of a virtual square lattice. It suffices if the lattice points coincide with lattice points in the extended square lattice defined by setting the same lattice structure as the lattice. FIG. 23 shows a modification of the phase modulation layer as viewed along the layer thickness direction (Z-axis direction). In FIG. 23, the outer contour (outer region B) represents a part of the phase modulation region. The inner region A surrounded by the outer region B is a phase modulation region (substantially the same as in the first to fourth embodiments) including a beam projection region and a plurality of different refractive index regions for generating a beam projection pattern. A plurality of unit configuration regions R). Therefore, in the example of FIG. 23, the phase modulation region of the phase modulation layer is configured by an inner region A and an outer region B. As described above, the outer region B is a region including a plurality of peripheral lattice point different refractive index regions having centroids at lattice point positions in a virtual square lattice. An example thereof is shown below. That is, the lattice constant of the virtual square lattice in the outer region B is equal to the lattice constant of the virtual square lattice in the inner region A, and the shape and size of each peripheral lattice point different refractive index region in the outer region B It may be equal to the shape and size of the different refractive index region in the region A. According to this modification, light leakage in the in-plane direction is suppressed, and the oscillation threshold current can be reduced.
また、図4および図5には、基本領域中の仮想的な正方格子における各格子点から所定の距離だけずれた場所に重心G1を有する異屈折率領域(以下、「変位異屈折率領域」という)が、各単位構成領域内に1つずつ設けられる例が示されていた。しかしながら、変位異屈折率領域は、全体の重心が上記各格子点から所定の距離だけずれた場所に位置するように、複数個に分割して設けられてもよい。また、変位異屈折率領域に加えて、各格子点上に格子点異屈折率領域が設けられてもよい。格子点異屈折率領域は、変位異屈折率領域と同様に基本領域の屈折率(第1屈折率)とは異なる屈折率を有する領域であるが、変位異屈折率領域と同じ材料(同じ屈折率の材料)で構成されてもよいし、その一部が変位異屈折率領域の一部と重なっていてもよい。
4 and 5 show a different refractive index region (hereinafter referred to as “displaced different refractive index region”) having a center of gravity G1 at a position shifted by a predetermined distance from each lattice point in the virtual square lattice in the basic region. However, an example in which one unit configuration area is provided is shown. However, the displacement different refractive index region may be divided into a plurality of portions so that the entire center of gravity is located at a position shifted from the respective lattice points by a predetermined distance. Further, in addition to the displacement different refractive index region, a lattice point different refractive index region may be provided on each lattice point. The lattice point different refractive index region is a region having a refractive index different from the refractive index of the basic region (first refractive index) in the same manner as the displacement different refractive index region. Material), or part of it may overlap with part of the displacement refractive index region.
ここで、図24~図26を参照して、変位異屈折率領域に加えて格子点異屈折率領域を設ける場合の例について説明する。図24は、変位異屈折率領域に加えて格子点異屈折率領域を設ける場合の、変位異屈折率領域の重心と格子点異屈折率領域との位置関係を説明するための図である。図25は、変位異屈折率領域に加えて格子点異屈折率領域が設けられる場合の、変位異屈折率領域と格子点屈折率領域の組合せの例(回転方式)を示す図である。図26は、変位異屈折率領域に加えて格子点異屈折率領域を設ける場合の変形例(回転方式)を示す図である。
Here, with reference to FIG. 24 to FIG. 26, an example in which a lattice point different refractive index region is provided in addition to the displacement different refractive index region will be described. FIG. 24 is a diagram for explaining the positional relationship between the center of gravity of the displacement different refractive index region and the lattice point different refractive index region when a lattice point different refractive index region is provided in addition to the displacement different refractive index region. FIG. 25 is a diagram showing an example (rotation method) of a combination of a displacement different refractive index region and a lattice point refractive index region when a lattice point different refractive index region is provided in addition to the displacement different refractive index region. FIG. 26 is a diagram showing a modification (rotation method) in the case where a lattice point different refractive index region is provided in addition to the displacement different refractive index region.
これらの図において、Oは格子点、G1は変位屈折率領域の重心、G2は格子点異屈折率領域の重心をそれぞれ表している。図24に示されたように、変位異屈折率領域n04-mbの重心G1と格子点Oとの位置関係は図5と同じであるが、図24では、それに加えて格子点異屈折率領域n04-mcが設けられている。図24では、格子点異屈折率領域n04-mcの重心G2は格子点Oと重なっているが、図26に示されたように、その重心G2は必ずしも格子点Oの上になくても良い。図24では、変位異屈折率領域n04-mbと格子点異屈折率領域n04-mcは何れも円形で両者は相互に重なっていないが、両者の組合せはこれに限られない。
In these figures, O represents a lattice point, G1 represents the center of gravity of the displacement refractive index region, and G2 represents the center of gravity of the lattice point different refractive index region. As shown in FIG. 24, the positional relationship between the center of gravity G1 of the displacement refractive index region n04-mb and the lattice point O is the same as that in FIG. 5, but in FIG. n04-mc is provided. In FIG. 24, the center of gravity G2 of the lattice point different refractive index region n04-mc overlaps with the lattice point O, but the center of gravity G2 does not necessarily have to be above the lattice point O as shown in FIG. . In FIG. 24, the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc are both circular and do not overlap each other, but the combination of both is not limited to this.
図25に示されたように、変位異屈折率領域n04-mbと格子点異屈折率領域n04-mcの組合せとしては種々の組合せが考えられる。図25(a)は図24の組合せである。図25(b)は変位異屈折率領域n04-mbと格子点異屈折率領域n04-mcが共に正方形の組合せである。図25(c)は、変位異屈折率領域n04-mbと格子点異屈折率領域n04-mcが共に円形であるが、両者の一部どうしが重なっている組合せである。図25(d)は、変位異屈折率領域n04-mbと格子点異屈折率領域n04-mcが共に正方形で、両者の一部どうしが重なっている組合せである。図25(e)は、図25(d)の変位異屈折率領域n04-mbと格子点異屈折率領域n04-mcを、それぞれの重心G1、G2(格子点O)を中心に任意に回転させ、両者が相互に重ならないようにした組合せである。図25(f)は、変位異屈折率領域n04-mbが三角形で、格子点異屈折率領域n04-mcが正方形の組合せである。図25(g)は、図25(f)の変位異屈折率領域n04-mbと格子点異屈折率領域n04-mcを、それぞれの重心G1、G2(格子点O)を中心に任意に回転させ、両者が相互に重ならないようにした組合せである。図25(h)は、図25(a)の変位異屈折率領域n04-mbが二つの円形の領域に分割された組合せである。図25(i)は、変位異屈折率領域n04-mbが正方形と三角形に分割され、格子点異屈折率領域n04-mcが三角形とされた組合せである。図25(j)は、図25(i)の変位異屈折率領域n04-mbと格子点異屈折率領域n04-mcを、それぞれの重心G1、G2(格子点O)を中心に任意に回転させた組合せである。図25(k)は、変位異屈折率領域n04-mbと格子点異屈折率領域n04-mcが共に正方形で、変位異屈折率領域n04-mbは2つの正方形に分割されており、各正方形の辺の方向が同一方向を向いている組み合せである。変位異屈折率領域に加えて格子点異屈折率領域が設けられる場合には、その両者を合わせた異屈折率領域全体が180°の回転対称性を備えなくなるので、より高い光出力を得ることができる。
As shown in FIG. 25, various combinations are possible as the combination of the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc. FIG. 25A is a combination of FIG. FIG. 25 (b) shows a combination of squares of the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc. FIG. 25C shows a combination in which the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc are both circular, but a part of both overlaps each other. FIG. 25 (d) shows a combination in which the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc are both square and a part of both overlaps. FIG. 25 (e) arbitrarily rotates the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc of FIG. 25 (d) around the center of gravity G1, G2 (lattice point O). The combination is such that they do not overlap each other. In FIG. 25 (f), the displacement different refractive index region n04-mb is a triangle and the lattice point different refractive index region n04-mc is a combination of squares. FIG. 25 (g) arbitrarily rotates the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc of FIG. 25 (f) around the respective centroids G1 and G2 (lattice points O). The combination is such that they do not overlap each other. FIG. 25H shows a combination in which the displacement different refractive index region n04-mb of FIG. 25A is divided into two circular regions. FIG. 25 (i) shows a combination in which the displacement different refractive index region n04-mb is divided into a square and a triangle, and the lattice point different refractive index region n04-mc is a triangle. FIG. 25 (j) arbitrarily rotates the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc of FIG. 25 (i) around the center of gravity G1, G2 (lattice point O). It is a combination. In FIG. 25 (k), the displacement different refractive index region n04-mb and the lattice point different refractive index region n04-mc are both square, and the displacement different refractive index region n04-mb is divided into two squares. This is a combination in which the directions of the sides are oriented in the same direction. In the case where a grating point different refractive index region is provided in addition to the displacement different refractive index region, the entire different refractive index region including both of them does not have a rotational symmetry of 180 °, so that a higher light output can be obtained. Can do.
異屈折率領域(周辺格子点異屈折率領域、格子点異屈折率領域を含む。)の形状が直線状の辺を有する形状とされる場合には、その辺の方向を、共通基板層を構成する結晶の特定の面方位に揃える事が望ましい。そうすれば、異屈折率領域をアルゴン、窒素または空気等が封入された空孔とする場合に、空孔の形状の制御が容易になり、空孔の上に成長させる結晶層の欠陥を抑制することができる。
When the shape of the different refractive index region (including the peripheral grating point different refractive index region and the grating point different refractive index region) is a shape having a straight side, the direction of the side is set to the common substrate layer. It is desirable to align with a specific plane orientation of the crystal to be formed. This makes it easy to control the shape of the holes when the refractive index region is filled with argon, nitrogen, air, or the like, and suppresses defects in the crystal layer that grows on the holes. can do.
なお、各格子点に対応して設けられる異屈折率領域(周辺格子点異屈折率領域、格子点異屈折率領域を含む)の形状や数は、1つの位相変調領域内で必ずしも同一である必要はない。図27(図4に示された位相変調層n04-mの第2変形例)に示されたように、格子点ごとに異屈折率領域の形状や数が異なっていてもよい。
Note that the shape and number of the different refractive index regions (including the peripheral grating point different refractive index region and the grating point different refractive index region) provided corresponding to each lattice point are not necessarily the same in one phase modulation region. There is no need. As shown in FIG. 27 (second modification of the phase modulation layer n04-m shown in FIG. 4), the shape and number of different refractive index regions may be different for each lattice point.
次に、位相変調層n04-mにおける異屈折率領域n04-mbの配置パターンを軸上シフト方式により決定する場合について説明する。なお、位相変調層n04-mにおける異屈折率領域n04-mbの配置パターン決定方法として、上述の回転方式に替えて軸上シフト方式が適用された場合でも、得られた位相変調層は上述の種々の実施形態に係る当該半導体発光モジュールに適用される。
Next, a case where the arrangement pattern of the different refractive index regions n04-mb in the phase modulation layer n04-m is determined by the on-axis shift method will be described. Even when the axial shift method is applied in place of the rotation method described above as the method for determining the arrangement pattern of the different refractive index regions n04-mb in the phase modulation layer n04-m, the obtained phase modulation layer is the same as that described above. The present invention is applied to the semiconductor light emitting module according to various embodiments.
図28は、位相変調層n04-mにおける異屈折率領域n04-mbの配置パターン(軸上シフト方式)を説明するための模式図である。位相変調層n04-mは、第1屈折率の基本領域n04-maと、第1屈折率とは異なる第2屈折率からなる異屈折率領域n04-mbとを含む。ここで、位相変調層n04-mには、図4の例と同様に、X-Y平面上で規定される仮想的な正方格子が設定される。正方格子の一辺はX軸と平行であり、他辺はY軸と平行である。このとき、正方格子の格子点Oを中心とする正方形状の単位構成領域Rが、X軸に沿った複数列(x1~x4)およびY軸に沿った複数行(y1~y3)に亘って二次元状に設定される。それぞれの単位構成領域Rの座標をぞれぞれの単位構成領域Rの重心位置で与えられることとすると、この重心位置は仮想的な正方格子の格子点Oに一致する。複数の異屈折率領域n04-mbは、各単位構成領域R内に1つずつ設けられる。異屈折率領域n04-mbの平面形状は、例えば円形状である。格子点Oは、異屈折率領域n04-mbの外部に位置しても良いし、異屈折率領域n04-mbの内部に含まれていてもよい。
FIG. 28 is a schematic diagram for explaining the arrangement pattern (on-axis shift method) of the different refractive index regions n04-mb in the phase modulation layer n04-m. The phase modulation layer n04-m includes a basic region n04-ma having a first refractive index and a different refractive index region n04-mb having a second refractive index different from the first refractive index. Here, a virtual square lattice defined on the XY plane is set in the phase modulation layer n04-m, as in the example of FIG. One side of the square lattice is parallel to the X axis, and the other side is parallel to the Y axis. At this time, the square unit constituting region R centering on the lattice point O of the square lattice extends over a plurality of columns (x1 to x4) along the X axis and a plurality of rows (y1 to y3) along the Y axis. Set in two dimensions. If the coordinates of each unit configuration region R are given by the centroid position of each unit configuration region R, the centroid position coincides with the lattice point O of a virtual square lattice. A plurality of different refractive index regions n04-mb is provided in each unit constituting region R. The planar shape of the different refractive index region n04-mb is, for example, a circular shape. The lattice point O may be located outside the different refractive index region n04-mb, or may be included inside the different refractive index region n04-mb.
なお、1つの単位構成領域R内に占める異屈折率領域n04-mbの面積Sの比率は、フィリングファクタ(FF)と称される。正方格子の格子間隔をaとすると、異屈折率領域n04-mbのフィリングファクタFFはS/a2として与えられる。SはX-Y平面における異屈折率領域n04-mbの面積であり、異屈折率領域n04-mbの形状が例えば真円の場合、真円の直径Dを用いてS=π(D/2)2として与えられる。また、異屈折率領域n04-mbの形状が正方形の場合、正方形の一辺の長さLAを用いてS=LA2として与えられる。
The ratio of the area S of the different refractive index regions n04-mb occupying in one unit constituent region R is called a filling factor (FF). When the lattice spacing of the square lattice is a, the filling factor FF of the different refractive index region n04-mb is given as S / a 2 . S is the area of the different refractive index region n04-mb in the XY plane. When the shape of the different refractive index region n04-mb is a perfect circle, for example, S = π (D / 2 ) Given as 2 . When the shape of the different refractive index region n04-mb is a square, S = LA 2 is given using the length LA of one side of the square.
図29は、軸シフト方式により決定される配置パターンの一例として、異屈折率領域n04-mbの重心G1と仮想的な正方格子における格子点O(x,y)との位置関係を説明するための図である。図29に示されたように、各異屈折率領域n04-mbの重心G1は、直線L上に配置されている。直線Lは、単位構成領域R(x,y)の対応する格子点O(x,y)を通り、正方格子の各辺に対して傾斜する直線である。言い換えると、直線Lは、単位構成領域R(x,y)を規定するs軸およびt軸の双方に対して傾斜する直線である。s軸に対する直線Lの傾斜角はθである。傾斜角θは、位相変調層n04-m内において一定である。傾斜角θは、0°<θ<90°を満たし、一例ではθ=45°である。または、傾斜角θは、180°<θ<270°を満たし、一例ではθ=225°である。傾斜角θが0°<θ<90°または180°<θ<270°を満たす場合、直線Lは、s軸およびt軸によって規定される座標平面の第1象限から第3象限に亘って延びる。或いは、傾斜角θは、90°<θ<180°を満たし、一例ではθ=135°である。あるいは、傾斜角θは、270°<θ<360°を満たし、一例ではθ=315°である。傾斜角θが90°<θ<180°または270°<θ<360°を満たす場合、直線Lは、s軸およびt軸によって規定される座標平面の第2象限から第4象限にわたって延びる。このように、傾斜角θは、0°、90°、180°および270°を除く角度である。ここで、格子点O(x,y)と重心G1との距離をr(x,y)とする。xはX軸におけるx番目の格子点の位置、yはY軸におけるy番目の格子点の位置を示す。距離r(x,y)が正の値である場合、重心G1は第1象限(または第2象限)に位置する。距離r(x,y)が負の値である場合、重心G1は第3象限(または第4象限)に位置する。距離r(x,y)が0である場合、格子点Oと重心G1とは互いに一致する。
FIG. 29 illustrates, as an example of an arrangement pattern determined by the axis shift method, the positional relationship between the center of gravity G1 of the different refractive index region n04-mb and the lattice point O (x, y) in the virtual square lattice. FIG. As shown in FIG. 29, the center of gravity G1 of each different refractive index region n04-mb is arranged on a straight line L. The straight line L is a straight line that passes through the corresponding lattice point O (x, y) of the unit configuration region R (x, y) and is inclined with respect to each side of the square lattice. In other words, the straight line L is a straight line that is inclined with respect to both the s axis and the t axis that define the unit configuration region R (x, y). The inclination angle of the straight line L with respect to the s-axis is θ. The inclination angle θ is constant in the phase modulation layer n04-m. The inclination angle θ satisfies 0 ° <θ <90 °, and in one example, θ = 45 °. Alternatively, the inclination angle θ satisfies 180 ° <θ <270 °, and in one example, θ = 225 °. When the inclination angle θ satisfies 0 ° <θ <90 ° or 180 ° <θ <270 °, the straight line L extends from the first quadrant to the third quadrant of the coordinate plane defined by the s axis and the t axis. . Alternatively, the inclination angle θ satisfies 90 ° <θ <180 °, and in one example, θ = 135 °. Alternatively, the inclination angle θ satisfies 270 ° <θ <360 °, and in one example, θ = 315 °. When the inclination angle θ satisfies 90 ° <θ <180 ° or 270 ° <θ <360 °, the straight line L extends from the second quadrant to the fourth quadrant of the coordinate plane defined by the s axis and the t axis. Thus, the inclination angle θ is an angle excluding 0 °, 90 °, 180 °, and 270 °. Here, the distance between the lattice point O (x, y) and the center of gravity G1 is r (x, y). x represents the position of the xth lattice point on the X axis, and y represents the position of the yth lattice point on the Y axis. When the distance r (x, y) is a positive value, the center of gravity G1 is located in the first quadrant (or the second quadrant). When the distance r (x, y) is a negative value, the center of gravity G1 is located in the third quadrant (or the fourth quadrant). When the distance r (x, y) is 0, the lattice point O and the center of gravity G1 coincide with each other.
図28に示された、各異屈折率領域n04-mbの重心G1と、単位構成領域R(x,y)の対応する格子点O(x,y)との距離r(x,y)は、目標ビーム投射パターン(光像)に応じて各異屈折率領域n04-mbごとに個別に設定される。距離r(x,y)の分布は、x(図28の例ではx1~x4)とy(図28の例ではy1~y3)の値で決まる位置ごとに特定の値を有するが、必ずしも特定の関数で表わされるとは限らない。距離r(x,y)の分布は、目標ビーム投射パターンを逆フーリエ変換して得られる複素振幅分布のうち位相分布を抽出したものから決定される。すなわち、図29に示された、単位構成領域R(x,y)における位相P(x,y)がP0である場合には距離r(x,y)が0に設定され、位相P(x,y)がπ+P0である場合には距離r(x,y)が最大値R0に設定され、位相P(x,y)が-π+P0である場合には距離r(x,y)が最小値-R0に設定される。そして、その中間の位相P(x,y)に対しては、r(x,y)={P(x,y)-P0}×R0/πとなるように距離r(x,y)が設定される。ここで、初期位相P0は任意に設定することができる。正方格子の格子間隔をaとすると、r(x,y)の最大値R0は、例えば、以下の式(10)の範囲である。
なお、目標ビーム投射パターンから複素振幅分布を求める際には、ホログラム生成の計算時に一般的に用いられるGerchberg-Saxton(GS)法のような繰り返しアルゴリズムを適用することによって、ビーム投射パターンの再現性が向上する。
The distance r (x, y) between the centroid G1 of each of the different refractive index regions n04-mb and the corresponding lattice point O (x, y) in the unit configuration region R (x, y) shown in FIG. Each of the different refractive index regions n04-mb is individually set according to the target beam projection pattern (light image). The distribution of the distance r (x, y) has a specific value for each position determined by the values of x (x1 to x4 in the example of FIG. 28) and y (y1 to y3 in the example of FIG. 28), but is not necessarily specified It is not always expressed by the function of The distribution of the distance r (x, y) is determined from the phase amplitude extracted from the complex amplitude distribution obtained by inverse Fourier transform of the target beam projection pattern. That is, when the phase P (x, y) in the unit configuration region R (x, y) shown in FIG. 29 is P 0 , the distance r (x, y) is set to 0, and the phase P ( The distance r (x, y) is set to the maximum value R 0 when x, y) is π + P 0 , and the distance r (x, y) when the phase P (x, y) is −π + P 0. ) Is set to the minimum value -R 0 . For the intermediate phase P (x, y), the distance r (x, y) is such that r (x, y) = {P (x, y) −P 0 } × R 0 / π. ) Is set. Here, the initial phase P 0 can be set arbitrarily. When the lattice spacing of the square lattice is a, the maximum value R 0 of r (x, y) is, for example, in the range of the following formula (10).
When obtaining the complex amplitude distribution from the target beam projection pattern, the reproducibility of the beam projection pattern is applied by applying an iterative algorithm such as the Gerchberg-Saxton (GS) method that is generally used when calculating the hologram generation. Will improve.
図30は、図28の位相変調層の第1変形例として、位相変調層の特定領域内にのみ屈折率略周期構造を適用した例を示す平面図である。図30に示された例では、図23に示された例と同様に、正方形の内側領域RINの内部に、目的となるビーム投射パターンを出射するための略周期構造(例:図28の構造)が形成されている。一方、内側領域RINを囲む外側領域ROUTには、正方格子の格子点位置に、重心位置が一致する真円形の異屈折率領域が配置されている。内側領域RINおよび外側領域ROUTにおいて、仮想的に設定される正方格子の格子間隔は互いに同一(=a)である。この構造の場合、外側領域ROUT内にも光が分布することにより、内側領域RINの周辺部において光強度が急激に変化することで生じる高周波ノイズ(いわゆる窓関数ノイズ)の発生を抑制することができる。また、面内方向への光漏れを抑制することができ、閾値電流の低減が期待できる。
FIG. 30 is a plan view showing an example in which a refractive index substantially periodic structure is applied only in a specific region of the phase modulation layer as a first modification of the phase modulation layer in FIG. In the example shown in FIG. 30, similar to the example shown in FIG. 23, a substantially periodic structure (for example, the structure of FIG. 28) for emitting a target beam projection pattern inside the square inner region RIN. ) Is formed. On the other hand, in the outer region ROUT surrounding the inner region RIN, a true circular different refractive index region having a centroid position coincident with a lattice point position of a square lattice is arranged. In the inner region RIN and the outer region ROUT, the lattice intervals of the square lattice that are virtually set are the same (= a). In the case of this structure, it is possible to suppress the generation of high-frequency noise (so-called window function noise) caused by a rapid change in light intensity in the peripheral portion of the inner region RIN by distributing light also in the outer region ROUT. it can. In addition, light leakage in the in-plane direction can be suppressed, and a reduction in threshold current can be expected.
なお、上述の種々の実施形態に係る半導体発光モジュールにおける複数の半導体発光素子それぞれから出力されるビーム投射パターンとして得られる光像と、位相変調層n04-mにおける位相分布P(x,y)との関係は、上述の回転方式の場合(図5)と同様である。したがって、正方格子を規定する上記第1の前提条件、上記式(1)~式(3)で規定される上記第2の前提条件、上記式(4)および(5)で規定される上記第3の前提条件、および上記式(6)および式(7)で既定される上記第4の前提条件の下、位相変調層n04-mは、以下の条件を満たすよう構成される。すなわち、格子点O(x,y)から対応する異屈折率領域n04-mbの重心Gまでの距離r(x,y)が、
r(x,y)=C×(P(x,y)-P0)
C:比例定数で例えばR0/π
P0:任意の定数であって例えば0
なる関係を満たすように、該対応する異屈折率領域n04-mbが単位構成領域R(x,y)内に配置される。すなわち、距離r(x,y)は、単位構成領域R(x,y)における位相P(x,y)がP0である場合には0に設定され、位相P(x,y)がπ+P0である場合には最大値R0に設定され、位相P(x,y)が-π+P0である場合には最小値-R0に設定される。目標ビーム投射パターンを得たい場合、該目標ビーム投射パターンを逆フーリエ変換して、その複素振幅の位相P(x,y)に応じた距離r(x,y)の分布を、複数の異屈折率領域n04-mbに与えるとよい。位相P(x,y)と距離r(x,y)とは、互いに比例してもよい。 Note that an optical image obtained as a beam projection pattern output from each of the plurality of semiconductor light emitting elements in the semiconductor light emitting modules according to the various embodiments described above, and the phase distribution P (x, y) in the phase modulation layer n04-m This relationship is the same as in the case of the rotation method described above (FIG. 5). Therefore, the first precondition defining the square lattice, the second precondition defined by the expressions (1) to (3), and the first precondition defined by the expressions (4) and (5). The phase modulation layer n04-m is configured to satisfy the following conditions under the three preconditions and the fourth precondition defined by the above formulas (6) and (7). That is, the distance r (x, y) from the lattice point O (x, y) to the centroid G of the corresponding different refractive index region n04-mb is
r (x, y) = C × (P (x, y) −P 0 )
C: proportionality constant, for example R 0 / π
P 0 : Arbitrary constant, for example, 0
The corresponding different refractive index region n04-mb is arranged in the unit configuration region R (x, y) so as to satisfy the following relationship. That is, the distance r (x, y) is set to 0 when the phase P (x, y) in the unit configuration region R (x, y) is P 0 , and the phase P (x, y) is π + P. When it is 0, it is set to the maximum value R 0 , and when the phase P (x, y) is −π + P 0, it is set to the minimum value −R 0 . When it is desired to obtain the target beam projection pattern, the target beam projection pattern is subjected to inverse Fourier transform, and the distribution of the distance r (x, y) according to the phase P (x, y) of the complex amplitude is obtained. It may be given to the rate region n04-mb. The phase P (x, y) and the distance r (x, y) may be proportional to each other.
r(x,y)=C×(P(x,y)-P0)
C:比例定数で例えばR0/π
P0:任意の定数であって例えば0
なる関係を満たすように、該対応する異屈折率領域n04-mbが単位構成領域R(x,y)内に配置される。すなわち、距離r(x,y)は、単位構成領域R(x,y)における位相P(x,y)がP0である場合には0に設定され、位相P(x,y)がπ+P0である場合には最大値R0に設定され、位相P(x,y)が-π+P0である場合には最小値-R0に設定される。目標ビーム投射パターンを得たい場合、該目標ビーム投射パターンを逆フーリエ変換して、その複素振幅の位相P(x,y)に応じた距離r(x,y)の分布を、複数の異屈折率領域n04-mbに与えるとよい。位相P(x,y)と距離r(x,y)とは、互いに比例してもよい。 Note that an optical image obtained as a beam projection pattern output from each of the plurality of semiconductor light emitting elements in the semiconductor light emitting modules according to the various embodiments described above, and the phase distribution P (x, y) in the phase modulation layer n04-m This relationship is the same as in the case of the rotation method described above (FIG. 5). Therefore, the first precondition defining the square lattice, the second precondition defined by the expressions (1) to (3), and the first precondition defined by the expressions (4) and (5). The phase modulation layer n04-m is configured to satisfy the following conditions under the three preconditions and the fourth precondition defined by the above formulas (6) and (7). That is, the distance r (x, y) from the lattice point O (x, y) to the centroid G of the corresponding different refractive index region n04-mb is
r (x, y) = C × (P (x, y) −P 0 )
C: proportionality constant, for example R 0 / π
P 0 : Arbitrary constant, for example, 0
The corresponding different refractive index region n04-mb is arranged in the unit configuration region R (x, y) so as to satisfy the following relationship. That is, the distance r (x, y) is set to 0 when the phase P (x, y) in the unit configuration region R (x, y) is P 0 , and the phase P (x, y) is π + P. When it is 0, it is set to the maximum value R 0 , and when the phase P (x, y) is −π + P 0, it is set to the minimum value −R 0 . When it is desired to obtain the target beam projection pattern, the target beam projection pattern is subjected to inverse Fourier transform, and the distribution of the distance r (x, y) according to the phase P (x, y) of the complex amplitude is obtained. It may be given to the rate region n04-mb. The phase P (x, y) and the distance r (x, y) may be proportional to each other.
なお、レーザビームのフーリエ変換後の遠視野像は、単一若しくは複数のスポット形状、円環形状、直線形状、文字形状、二重円環形状、または、ラゲールガウスビーム形状などの各種の形状をとることができる。ビーム方向を制御することもできるので、上述の種々の実施形態に係る半導体発光モジュールにおける複数の半導体発光素子それぞれを一次元または二次元にアレイ化することによって、例えば高速走査を電気的に行うレーザ加工機を実現できる。なお、ビーム投射パターンは遠方界における角度情報で表わされるものであるので、目標ビーム投射パターンが二次元的な位置情報で表わされているビットマップ画像などの場合には、一旦角度情報に変換し、その後波数空間に変換した後に逆フーリエ変換を行うとよい。
The far-field image after Fourier transformation of the laser beam has various shapes such as single or multiple spot shapes, circular shapes, linear shapes, character shapes, double annular shapes, or Laguerre Gaussian beam shapes. Can take. Since the beam direction can also be controlled, for example, a laser that performs high-speed scanning electrically by arraying each of a plurality of semiconductor light-emitting elements in the semiconductor light-emitting modules according to the various embodiments described above one-dimensionally or two-dimensionally. A processing machine can be realized. Since the beam projection pattern is represented by angle information in the far field, in the case of a bitmap image or the like where the target beam projection pattern is represented by two-dimensional position information, it is once converted into angle information. Then, it is preferable to perform inverse Fourier transform after conversion to wave number space.
逆フーリエ変換で得られた複素振幅分布から強度分布と位相分布を得る方法として、例えば強度分布I(x,y)については、MathWorks社の数値解析ソフトウェア「MATLAB」のabs関数を用いることにより計算することができ、位相分布P(x,y)については、MATLABのangle関数を用いることにより計算することができる。
As a method for obtaining the intensity distribution and the phase distribution from the complex amplitude distribution obtained by the inverse Fourier transform, for example, the intensity distribution I (x, y) is calculated by using the abs function of the numerical analysis software “MATLAB” of MathWorks. The phase distribution P (x, y) can be calculated by using an angle function of MATLAB.
ここで、目標ビーム投射パターンの逆フーリエ変換結果から位相分布P(x,y)を求め、各異屈折率領域n04-mbの距離r(x,y)を決める際に、一般的な離散フーリエ変換(或いは高速フーリエ変換)を用いて計算する場合の留意点を述べる。なお、図31は、目標ビーム投射パターンの逆フーリエ変換結果から位相角分布(回転方式における回転角度分布に相当)を求め、異屈折率領域の配置を決める際の留意点を説明する図である。目標ビーム投射パターンである図31(a)の逆フーリエ変換で得られた複素振幅分布より計算されるビーム投射パターンは、図31(b)に示された状態になる。図31(a)と図31(b)のように、それぞれA1,A2,A3,およびA4といった4つの象限に分割すると、図31(b)のビーム投射パターンの第1象限には、図31(a)の第1象限の、180度回転したパターンと図31(a)の第3象限のパターンとが重畳した重畳パターンが現れる。図31(b)の第2象限には、図31(a)の第2象限の、180度回転したパターンと図31(a)の第4象限のパターンが重畳した重畳パターンが現れる。図31(b)の第3象限には、図31(a)の第3象限の、180度回転したパターンと図31(a)の第1象限のパターンが重畳した重畳パターンが現れる。図31(b)の第4象限には、図31(a)の第4象限の、180度回転したパターンと図31(a)の第2象限のパターンが重畳した重畳パターンが現れる。このとき、180度回転したパターンは-1次光成分によるパターンである。
Here, when the phase distribution P (x, y) is obtained from the inverse Fourier transform result of the target beam projection pattern and the distance r (x, y) of each of the different refractive index regions n04-mb is determined, a general discrete Fourier is used. Points to note when calculating using transformation (or fast Fourier transformation) are described. FIG. 31 is a diagram for explaining points to consider when determining the arrangement of the different refractive index regions by obtaining the phase angle distribution (corresponding to the rotation angle distribution in the rotation method) from the inverse Fourier transform result of the target beam projection pattern. . The beam projection pattern calculated from the complex amplitude distribution obtained by the inverse Fourier transform of FIG. 31A, which is the target beam projection pattern, is in the state shown in FIG. When divided into four quadrants A1, A2, A3, and A4 as shown in FIG. 31A and FIG. 31B, the first quadrant of the beam projection pattern in FIG. A superimposed pattern in which the pattern rotated by 180 degrees in the first quadrant of (a) and the pattern of the third quadrant of FIG. In the second quadrant of FIG. 31B, a superposed pattern in which the pattern rotated 180 degrees in the second quadrant of FIG. 31A and the pattern of the fourth quadrant of FIG. In the third quadrant of FIG. 31B, a superposed pattern in which the pattern rotated 180 degrees in the third quadrant of FIG. 31A and the pattern of the first quadrant of FIG. In the fourth quadrant of FIG. 31B, a superposed pattern in which the pattern rotated by 180 degrees in the fourth quadrant of FIG. 31A and the pattern of the second quadrant of FIG. At this time, the pattern rotated by 180 degrees is a pattern due to the −1st order light component.
したがって、逆フーリエ変換前の光像(元の光像)として第1象限のみに値を有するパターンを用いた場合には、得られるビーム投射パターンの第3象限に元の光像の第1象限が現れ、得られるビーム投射パターンの第1象限に元の光像の第1象限を180度回転したパターンが現れる。
Therefore, when a pattern having a value only in the first quadrant is used as the optical image before the inverse Fourier transform (original optical image), the first quadrant of the original optical image is added to the third quadrant of the obtained beam projection pattern. And a pattern obtained by rotating the first quadrant of the original optical image by 180 degrees appears in the first quadrant of the obtained beam projection pattern.
なお、上述の構造において、活性層および位相変調層を含む構成であれば、材料系、膜厚、層の構成は様々に変更され得る。ここで、仮想的な正方格子からの摂動が0の場合のいわゆる正方格子フォトニック結晶レーザに関してはスケーリング則が成り立つ。すなわち、波長が定数α倍となった場合には、正方格子構造全体をα倍することによって同様の定在波状態を得ることが出来る。同様に、本実施形態においても、波長に応じたスケーリング則によって位相変調層n04-mの構造を決定することが可能である。したがって、青色、緑色、赤色などの光を発光する活性層12を用い、波長に応じたスケーリング則を適用することで、可視光を出力する半導体発光素子を実現することも可能である。
In the above structure, the material system, the film thickness, and the layer configuration can be variously changed as long as the configuration includes the active layer and the phase modulation layer. Here, the scaling law holds for a so-called square lattice photonic crystal laser in which the perturbation from the virtual square lattice is zero. That is, when the wavelength becomes a constant α times, a similar standing wave state can be obtained by multiplying the entire square lattice structure by α times. Similarly, also in the present embodiment, the structure of the phase modulation layer n04-m can be determined by a scaling rule corresponding to the wavelength. Therefore, it is also possible to realize a semiconductor light emitting device that outputs visible light by using the active layer 12 that emits light of blue, green, red, and the like, and applying a scaling rule according to the wavelength.
なお、格子間隔aの正方格子の場合、直交座標の単位ベクトルをx、yとすると、基本並進ベクトルa1=ax、a2=ayであり、並進ベクトルa1、a2に対する基本逆格子ベクトルb1=(2π/a)x、b2=(2π/a)yである。格子の中に存在する波の波数ベクトルがk=nb1+mb2(n、mは任意の整数)の場合に、波数kはΓ点に存在するが、なかでも波数ベクトルの大きさが基本逆格子ベクトルの大きさに等しい場合には、格子間隔aが波長λに等しい共振モード(X-Y平面内における定在波)が得られる。上述の種々の実施形態では、このような共振モード(定在波状態)における発振が得られる。このとき、正方格子と平行な面内に電界が存在するようなTEモードを考えると、このように格子間隔と波長が等しい定在波状態は正方格子の対称性から4つのモードが存在する。上述の種々の実施形態では、この4つの定在波状態のいずれのモードで発振した場合においても同様に所望のビーム投射パターンが得られる。
In the case of a square lattice with a lattice interval a, if the unit vectors of orthogonal coordinates are x and y, the basic translation vectors a 1 = ax and a 2 = ay, and the basic reciprocal lattice vector for the translation vectors a 1 and a 2 b 1 = (2π / a) x, b 2 = (2π / a) y. When the wave number vector of a wave existing in the lattice is k = nb 1 + mb 2 (n and m are arbitrary integers), the wave number k exists at the Γ point. When it is equal to the magnitude of the grating vector, a resonance mode (standing wave in the XY plane) in which the grating interval a is equal to the wavelength λ is obtained. In the various embodiments described above, oscillation in such a resonance mode (standing wave state) is obtained. At this time, considering a TE mode in which an electric field exists in a plane parallel to the square lattice, the standing wave state having the same lattice spacing and wavelength has four modes due to the symmetry of the square lattice. In the above-described various embodiments, a desired beam projection pattern can be obtained in the same manner even when oscillating in any of the four standing wave states.
なお、上述の位相変調層n04-m内の定在波が孔形状によって散乱され、面垂直方向に得られる波面が位相変調されていることによって所望のビーム投射パターンが得られる。このため偏光板がなくとも所望のビーム投射パターンが得られる。このビーム投射パターンは、一対の単峰ビーム(スポット)であるばかりでなく、前述したように、文字形状、2以上の同一形状スポット群、或いは、位相、強度分布が空間的に不均一であるベクトルビームなどとすることも可能である。
Note that the standing wave in the phase modulation layer n04-m is scattered by the hole shape, and the wavefront obtained in the direction perpendicular to the plane is phase-modulated, whereby a desired beam projection pattern is obtained. Therefore, a desired beam projection pattern can be obtained without a polarizing plate. This beam projection pattern is not only a pair of unimodal beams (spots), but as described above, the character shape, two or more identically shaped spot groups, or the phase and intensity distribution are spatially non-uniform. It is also possible to use a vector beam or the like.
なお、一例として、基本領域n04-maの屈折率は3.0~3.5、異屈折率領域n04-mbの屈折率は1.0~3.4であることが好ましい。また、基本領域n04-maの孔内の各異屈折率領域n04-mbの平均半径は、940nm帯の場合、例えば20nm~120nmである。各異屈折率領域n04-mbの大きさが変化することによってZ軸方向への回折強度が変化する。この回折効率は、異屈折率領域n04-mbの形状をフーリエ変換した際の一次の係数で表される光結合係数κ1に比例する。光結合係数については、例えば、上記非特許文献2に記載されている。
As an example, the refractive index of the basic region n04-ma is preferably 3.0 to 3.5, and the refractive index of the different refractive index region n04-mb is preferably 1.0 to 3.4. Further, the average radius of each of the different refractive index regions n04-mb in the hole of the basic region n04-ma is, for example, 20 nm to 120 nm in the case of the 940 nm band. As the size of each of the different refractive index regions n04-mb changes, the diffraction intensity in the Z-axis direction changes. This diffraction efficiency is proportional to the optical coupling coefficient κ1 represented by a first-order coefficient when the shape of the different refractive index region n04-mb is Fourier transformed. The optical coupling coefficient is described in Non-Patent Document 2, for example.
以上のように軸上シフト方式に異屈折率領域n04-mbの配置パターンが決定された位相変調層n04-mを備えた半導体発光素子によって得られる効果について説明する。従来、半導体発光素子としては、各異屈折率領域n04-mbの重心G1が、仮想的な正方格子の対応する格子点Oから離れて配置されるとともに、各格子点O周りに光像に応じた回転角度を有するものが知られている(例えば特許文献1を参照)。しかしながら、各異屈折率領域n04-mbの重心G1と各格子点Oとの位置関係が従来とは異なる新しい発光装置を実現できれば、位相変調層n04-mの設計の幅が拡がり、極めて有用である。
The effects obtained by the semiconductor light emitting device including the phase modulation layer n04-m in which the arrangement pattern of the different refractive index regions n04-mb is determined by the on-axis shift method as described above will be described. Conventionally, as a semiconductor light emitting device, the center of gravity G1 of each of the different refractive index regions n04-mb is arranged away from the corresponding lattice point O of the virtual square lattice, and around the lattice points O according to the optical image. Those having a different rotation angle are known (see, for example, Patent Document 1). However, if a new light-emitting device in which the positional relationship between the center of gravity G1 of each different refractive index region n04-mb and each lattice point O is different from the conventional one can be realized, the design range of the phase modulation layer n04-m can be expanded, which is extremely useful. is there.
活性層に光学的に結合した位相変調層n04-mが、基本領域n04-maと、基本領域n04-maとは屈折率が異なる複数の異屈折率領域n04-mbとを有し、それぞれs軸およびt軸の直交座標系で規定される単位構成領域Rにおいて、仮想的な正方格子の格子点Oを通り該s軸および該t軸の双方に対して傾斜する直線L上に、各異屈折率領域n04-mbの重心G1が配置されている。そして、各異屈折率領域n04-mbの重心G1と、対応する格子点Oとの距離r(x,y)は、目標ビーム投射パターンに応じて個別に設定されている。このような場合、格子点Oと重心G1との距離に応じて、ビームの位相が変化する。すなわち、重心G1の位置を変更するのみで、各異屈折率領域n04-mbから出射されるビームの位相を制御することができ、全体として形成されるビーム投射パターンを所望の形状(目標ビーム投射パターン)とすることができる。すなわち、上述の半導体発光素子それぞれはS-iPMレーザであり、このような構造によれば、各異屈折率領域n04-mbの重心G1が各格子点O周りに目標ビーム投射パターンに応じた回転角度を有する従来の構造と同様に、怒りが出力される第1面に垂直な方向に対して傾斜した方向に任意形状のビーム投射パターンを出力することができる。このように、軸上シフト方式では、各異屈折率領域n04-mbの重心G1と各格子点Oとの位置関係が従来とは全く異なる半導体発光素子および半導体発光モジュールを提供することができる。
The phase modulation layer n04-m optically coupled to the active layer has a basic region n04-ma and a plurality of different refractive index regions n04-mb having a refractive index different from that of the basic region n04-ma. In the unit configuration region R defined by the orthogonal coordinate system of the axis and the t-axis, each of the different points on the straight line L that passes through the lattice point O of the virtual square lattice and is inclined with respect to both the s-axis and the t-axis. The center of gravity G1 of the refractive index region n04-mb is disposed. The distance r (x, y) between the center G1 of each of the different refractive index regions n04-mb and the corresponding lattice point O is individually set according to the target beam projection pattern. In such a case, the beam phase changes according to the distance between the lattice point O and the center of gravity G1. That is, the phase of the beam emitted from each of the different refractive index regions n04-mb can be controlled only by changing the position of the center of gravity G1, and the beam projection pattern formed as a whole can have a desired shape (target beam projection). Pattern). That is, each of the semiconductor light emitting elements described above is an S-iPM laser, and according to such a structure, the center of gravity G1 of each of the different refractive index regions n04-mb rotates around each lattice point O according to the target beam projection pattern. Similar to a conventional structure having an angle, a beam projection pattern having an arbitrary shape can be output in a direction inclined with respect to a direction perpendicular to the first surface where anger is output. As described above, the on-axis shift method can provide a semiconductor light emitting device and a semiconductor light emitting module in which the positional relationship between the gravity center G1 of each different refractive index region n04-mb and each lattice point O is completely different from the conventional one.
ここで、図32(a)は、半導体発光素子から出力されるビーム投射パターン(光像)の例を示す図である。図32(a)の中心は、半導体発光素子の発光面と交差し発光面に垂直な軸線に対応する。また、図32(b)は、半導体発光素子の発光面と交差し発光面に垂直な軸線を含む断面における光強度分布を示すグラフである。図32(b)は、FFP光学系(浜松ホトニクス製A3267-12)、カメラ(浜松ホトニクス製ORCA-05G)、ビームプロファイラ(浜松ホトニクス製Lepas-12)を用いて取得した遠視野像で、1344ドット×1024ドットの画像データの縦方向のカウントを積算し、プロットしたものである。なお、図32(a)の最大カウント数を255で規格化しており、また、±1次光の強度比を明示するために、中央の0次光B0を飽和させている。図32(b)から、1次光および-1次光の強度差が容易に理解される。また、図33(a)は、図32(a)に示されたビーム投射パターンに対応する位相分布を示す図である。図33(b)は、図33(a)の部分拡大図である。図33(a)および図33(b)においては、位相変調層n04-m内の各箇所における位相が濃淡によって示されており、暗部ほど位相角0°に、明部ほど位相角360°に近づく。ただし、位相角の中心値は任意に設定することができるので、必ずしも位相角を0°~360°の範囲内に設定しなくてもよい。図32(a)および図32(b)に示されたように、半導体発光素子は、該軸線に対して傾斜した第1方向に出力される第1光像部分B1を含む1次光と、該軸線に関して第1方向と対称である第2方向に出力され、該軸線に関して第1光像部分B1と回転対称である第2光像部分B2を含む-1次光とを出力する。典型的には、第1光像部分B1はX-Y平面内の第1象限に現れ、第2光像部分B2はX-Y平面内の第3象限に現れる。しかしながら、用途によっては、1次光のみを用い、-1次光を用いない場合がある。そのような場合、-1次光の光量が1次光と比較して小さく抑えられることが望ましい。
Here, FIG. 32A is a diagram showing an example of a beam projection pattern (light image) output from the semiconductor light emitting element. The center of FIG. 32A corresponds to an axis that intersects the light emitting surface of the semiconductor light emitting element and is perpendicular to the light emitting surface. FIG. 32B is a graph showing a light intensity distribution in a cross section including an axis that intersects the light emitting surface of the semiconductor light emitting element and is perpendicular to the light emitting surface. FIG. 32B is a far-field image 1344 acquired using an FFP optical system (A3267-12 manufactured by Hamamatsu Photonics), a camera (ORCA-05G manufactured by Hamamatsu Photonics), and a beam profiler (Lepas-12 manufactured by Hamamatsu Photonics). The counts in the vertical direction of dot × 1024 dot image data are integrated and plotted. Note that the maximum count number in FIG. 32A is normalized by 255, and the center zero-order light B0 is saturated in order to clearly indicate the intensity ratio of ± first-order light. From FIG. 32 (b), the difference in intensity between the primary light and the negative primary light can be easily understood. FIG. 33A is a diagram showing a phase distribution corresponding to the beam projection pattern shown in FIG. FIG. 33 (b) is a partially enlarged view of FIG. 33 (a). 33 (a) and 33 (b), the phase at each location in the phase modulation layer n04-m is shown by shading, with the dark portion having a phase angle of 0 ° and the bright portion having a phase angle of 360 °. Get closer. However, since the center value of the phase angle can be set arbitrarily, it is not always necessary to set the phase angle within the range of 0 ° to 360 °. As shown in FIG. 32A and FIG. 32B, the semiconductor light emitting element includes primary light including a first light image portion B1 output in a first direction inclined with respect to the axis, The first-order light is output in a second direction that is symmetric with respect to the first direction with respect to the axis, and includes the first light image portion B1 and the second light image portion B2 that is rotationally symmetric with respect to the axis. Typically, the first light image portion B1 appears in the first quadrant in the XY plane, and the second light image portion B2 appears in the third quadrant in the XY plane. However, in some applications, only the primary light is used and the −1st order light is not used. In such a case, it is desirable that the light amount of the −1st order light be suppressed to be smaller than that of the primary light.
図34は、各方向の進行波のビーム投射パターンの例を概念的に示す図である。この例では、単位構成領域Rにおいて、s軸およびt軸に対する直線Lの傾斜角を45°としている。正方格子型のS-iPMレーザの位相変調層では、X-Y平面に沿った基本的な進行波AU,AD,AR,およびALが生じる。進行波AUおよびADは、正方格子の各辺のうちY軸方向に延びる辺に沿って進む光である。進行波AUはY軸正方向に進み、進行波ADはY軸負方向に進む。また、進行波ARおよびALは、正方格子の各辺のうちX軸方向に延びる辺に沿って進む光である。進行波ARはX軸正方向に進み、進行波ALはX軸負方向に進む。この場合、互いに逆向きに進む進行波からは、それぞれ逆向きのビーム投射パターンが得られる。例えば、進行波AUからは第2光像部分B2のみを含むビーム投射パターンBUが得られ、進行波ADからは第1光像部分B1のみを含むビーム投射パターンBDが得られる。同様に、進行波ARからは第2光像部分B2のみを含むビーム投射パターンBRが得られ、進行波ALからは第1光像部分B1のみを含むビーム投射パターンBLが得られる。言い換えると、互いに逆向きに進む進行波同士では、一方が1次光となり他方が-1次光となる。半導体発光素子から出力されるビーム投射パターンは、これらのビーム投射パターンBU,BD,BR,およびBLが重なり合ったものである。
FIG. 34 is a diagram conceptually showing an example of a beam projection pattern of traveling waves in each direction. In this example, in the unit configuration region R, the inclination angle of the straight line L with respect to the s-axis and the t-axis is 45 °. In the phase modulation layer of the square lattice type S-iPM laser, basic traveling waves AU, AD, AR, and AL are generated along the XY plane. Traveling waves AU and AD are light traveling along the side extending in the Y-axis direction among the sides of the square lattice. The traveling wave AU travels in the Y-axis positive direction, and the traveling wave AD travels in the Y-axis negative direction. The traveling waves AR and AL are light traveling along the sides extending in the X-axis direction among the sides of the square lattice. The traveling wave AR travels in the positive direction of the X axis, and the traveling wave AL travels in the negative direction of the X axis. In this case, beam projection patterns in opposite directions are obtained from traveling waves traveling in opposite directions. For example, a beam projection pattern BU including only the second light image portion B2 is obtained from the traveling wave AU, and a beam projection pattern BD including only the first light image portion B1 is obtained from the traveling wave AD. Similarly, a beam projection pattern BR including only the second light image portion B2 is obtained from the traveling wave AR, and a beam projection pattern BL including only the first light image portion B1 is obtained from the traveling wave AL. In other words, in traveling waves traveling in opposite directions, one is primary light and the other is negative primary light. The beam projection pattern output from the semiconductor light emitting element is an overlap of these beam projection patterns BU, BD, BR, and BL.
本発明者らの検討によれば、異屈折率領域を格子点の周りで回転させる従来の半導体発光素子においては、異屈折率領域の配置の性質上、互いに逆向きに進む進行波の双方が必ず含まれる。すなわち、従来の方式では、定在波を形成する4つの進行波AU,AD,AR,およびALのいずれにおいても、1次光と-1次光とが同量現れ、更に回転円の半径(異屈折率領域の重心と格子点との距離)によっては0次光が生じてしまう。そのため、1次光および-1次光の各光量に差を与えることは原理的に困難で、これらのうち一方を選択的に低減することは難しい。従って、1次光の光量に対して-1次光の光量を相対的に低下させることは困難である。
According to the study by the present inventors, in the conventional semiconductor light emitting device in which the different refractive index region is rotated around the lattice point, both traveling waves traveling in opposite directions are caused by the nature of the arrangement of the different refractive index region. Always included. In other words, in the conventional method, the same amount of the first-order light and the −1st-order light appears in any of the four traveling waves AU, AD, AR, and AL forming the standing wave, and the radius of the rotating circle ( Depending on the distance between the center of gravity of the different refractive index region and the lattice point, zero-order light is generated. Therefore, in principle, it is difficult to give a difference between the light amounts of the primary light and the −1st light, and it is difficult to selectively reduce one of these. Therefore, it is difficult to reduce the light amount of the −1st order light relative to the light amount of the primary light.
ここで、図35は、上述の異屈折率領域n04-mbの配置パターンの決定方法として、異屈折率領域を格子点の周りで回転させる回転方式と、進行波AU,AD,AR,ALを示す図である。異屈折率領域n04-mbを格子点Oの周りで回転させる回転方式において、1次光および-1次光のいずれかを選択的に低減することが難しい理由を説明する。或る位置における設計位相φ(x,y)に対して、4つの進行波の1例として図35(b)に示されるt軸の正の向きの進行波AUを考える。このとき、幾何学的な関係から、進行波AUに対しては、格子点Oからのずれがr・sinφ(x,y)となるので、位相差は(2π/a)r・sinφ(x,y)なる関係となる。この結果、進行波AUに関する位相分布Φ(x,y)は、異屈折率領域n04-mbの大きさの影響が小さいためその影響を無視できる場合には、Φ(x,y)=exp{j(2π/a)r・sinφ(x,y)}で与えられる。この位相分布Φ(x,y)の0次光および±1次光への寄与は、exp{jnΦ(x,y)}(n:整数)で展開した場合の、n=0およびn=±1の成分で与えられる。ところで、次数nの第1種ベッセル関数Jn(z)に関する以下の式(11)で規定される数学公式を用いると、位相分布Φ(x,y)を級数展開することができ、0次光および±1次光の各光量を説明することができる。
このとき、位相分布Φ(x,y)の0次光成分はJ0(2πr/a)、1次光成分はJ1(2πr/a)、-1次光成分はJ-1(2πr/a)と表される。ところで、±1次のベッセル関数に関しては、J1(x)=-J-1(x)の関係があるため、±1次光成分の大きさは等しくなる。ここでは、4つの進行波の1例としてY軸正方向の進行波AUについて考えたが、他の3波(進行波AD,AR,AL)についても同様の関係が成立し、±1次光成分の大きさが等しくなる。以上の議論から、異屈折率領域n04-mbを格子点Oの周りで回転させる従来の方式では、±1次光成分の光量に差を与えることが原理的に困難となる。
Here, in FIG. 35, as a method for determining the arrangement pattern of the above-described different refractive index regions n04-mb, a rotation method in which the different refractive index regions are rotated around lattice points, and traveling waves AU, AD, AR, and AL are shown. FIG. The reason why it is difficult to selectively reduce either the first-order light or the −1st-order light in the rotation method in which the different refractive index region n04-mb is rotated around the lattice point O will be described. As an example of four traveling waves with respect to the design phase φ (x, y) at a certain position, a traveling wave AU having a positive direction of the t-axis shown in FIG. 35B is considered. At this time, because of the geometrical relationship, for the traveling wave AU, the deviation from the lattice point O is r · sinφ (x, y), so the phase difference is (2π / a) r · sinφ (x , Y). As a result, the phase distribution Φ (x, y) relating to the traveling wave AU has a small influence on the size of the different refractive index region n04-mb. Therefore, when the influence can be ignored, Φ (x, y) = exp { j (2π / a) r · sinφ (x, y)}. The contribution of the phase distribution Φ (x, y) to the 0th order light and ± 1st order light is expressed by n = 0 and n = ± when expanded by exp {jnΦ (x, y)} (n: integer). Given by one component. By the way, when the mathematical formula defined by the following equation (11) regarding the first-type Bessel function Jn (z) of order n is used, the phase distribution Φ (x, y) can be series-expanded, and the zero-order light And each light quantity of ± primary light can be explained.
At this time, the zero-order light component of the phase distribution Φ (x, y) is J 0 (2πr / a), the first-order light component is J 1 (2πr / a), and the −1st- order light component is J −1 (2πr / a). a). By the way, with respect to the ± 1st order Bessel functions, there is a relationship of J 1 (x) = − J −1 (x), and therefore the magnitudes of the ± 1st order light components are equal. Here, the Y-axis positive traveling wave AU is considered as an example of the four traveling waves, but the same relationship holds for the other three waves (traveling waves AD, AR, AL), and ± 1st order light The component sizes are equal. From the above discussion, in the conventional method in which the different refractive index region n04-mb is rotated around the lattice point O, it is theoretically difficult to give a difference in the light amount of the ± first-order light component.
これに対し、軸上シフト方式により異屈折率領域n04-mbの配置パターンが決定された位相変調層n04-mによれば、単一の進行波に対しては、1次光および-1次光の各光量に差が生じ、例えば傾斜角θが45°、135°、225°または315°である場合には、シフト量R0が上述した数式(9)の上限値に近づくほど、理想的な位相分布が得られる。この結果、0次光が低減され、進行波AU,AD,AR,およびALのそれぞれにおいては、1次光および-1次光の一方が選択的に低減される。そのため、互いに逆向きに進む進行波のいずれか一方を選択的に低減することで、1次光および-1次光の光量に差を与えることが原理的に可能である。
On the other hand, according to the phase modulation layer n04-m in which the arrangement pattern of the different refractive index regions n04-mb is determined by the axial shift method, the primary light and the −1st order are obtained for a single traveling wave. When there is a difference in each light quantity of light, for example, when the inclination angle θ is 45 °, 135 °, 225 °, or 315 °, the shift amount R 0 becomes closer to the upper limit value of the above-described equation (9), so that the ideal Phase distribution can be obtained. As a result, the zero-order light is reduced, and one of the first-order light and the −1st-order light is selectively reduced in each of the traveling waves AU, AD, AR, and AL. Therefore, in principle, it is possible to give a difference between the light amounts of the primary light and the −1st order light by selectively reducing one of the traveling waves traveling in opposite directions.
図36は、異屈折率領域n04-mbの配置パターンの決定方法として、格子点を通り正方格子に対して傾斜した軸線上で異屈折率領域を移動させる軸上シフト方式と、進行波AU,AD,AR,ALを示す図である。格子点Oを通る、単位構成領域Rを規定するs軸およびt軸の双方に対して傾斜した直線L上を異屈折率領域n04-mbの重心G1が移動する、図36(a)に示された、軸上シフト方式において、1次光および-1次光のいずれかを選択的に低減することが可能である理由を説明する。単位構成領域R(x,y)における設計位相φ(x,y)(回転方式における図5の回転角に相当)に対して、4つの進行波の1例として図36(b)に示されるy軸の正の向きの進行波AUを考える。このとき、幾何学的な関係から、進行波AUに対しては、格子点Oからのずれがr・sinθ・{φ(x,y)-φ0}/πとなるため、位相差は(2π/a)r・sinθ・{φ(x,y)-φ0}/πなる関係となる。ここでは簡単のため傾斜角θ=45°、位相角φ0=0°とする。このとき、進行波AUに関する位相分布Φ(x,y)(上述の位相分布P(x,y)に相当)は、異屈折率領域n04-mbの大きさの影響が小さいためその影響を無視できる場合には、以下の式(12)で与えられる。
この位相分布Φ(x,y)の0次光および±1次光への寄与は、exp{nΦ(x,y)}(n:整数)で展開した場合の、n=0およびn=±1の成分で与えられる。ところで、下記の式(13)によって表される関数f(z)をLaurent級数展開すると、以下の式(14)で規定される数学公式が成り立つ。
ここで、sinc(x)=x/sin(x)である。上記式(14)で規定される数学公式を用いると、位相分布Φ(x,y)を級数展開することができ、0次光および±1次光の各光量を説明することができる。このとき、上記式(14)の指数項exp{jπ(c-n)}の絶対値が1である点に注意すると、位相分布Φ(x,y)の0次光成分の大きさは、以下の式(15)で表される。
また、位相分布Φ(x,y)の1次光成分の大きさは、以下の式(16)で表される。
位相分布Φ(x,y)の-1次光成分の大きさは、以下の式(17)で表される。
そして、上記式(15)~(17)においては、以下の式(18)で規定される条件を満たす場合を除いて、1次光成分以外に0次光および-1次光成分が現れる。しかしながら、±1次光成分の大きさは互いに等しくならない。
FIG. 36 shows a method of determining the arrangement pattern of the different refractive index regions n04-mb, an axial shift method in which the different refractive index regions are moved on an axis that passes through the lattice points and is inclined with respect to the square lattice, and a traveling wave AU, It is a figure which shows AD, AR, and AL. The center of gravity G1 of the different refractive index region n04-mb moves on a straight line L passing through the lattice point O and inclined with respect to both the s-axis and the t-axis defining the unit constituent region R, as shown in FIG. The reason why it is possible to selectively reduce either the first-order light or the −1st-order light in the on-axis shift method will be described. FIG. 36B shows an example of four traveling waves with respect to the design phase φ (x, y) (corresponding to the rotation angle in FIG. 5 in the rotation method) in the unit configuration region R (x, y). Consider a traveling wave AU in the positive direction of the y-axis. At this time, because of the geometric relationship, the deviation from the lattice point O is r · sin θ · {φ (x, y) −φ 0 } / π for the traveling wave AU, and the phase difference is ( 2π / a) r · sin θ · {φ (x, y) −φ 0 } / π. Here, for simplicity, the inclination angle θ = 45 ° and the phase angle φ 0 = 0 °. At this time, the phase distribution Φ (x, y) (corresponding to the above-described phase distribution P (x, y)) relating to the traveling wave AU is negligibly affected by the size of the different refractive index region n04-mb. If possible, it is given by the following equation (12).
The contribution of the phase distribution Φ (x, y) to the 0th order light and the ± 1st order light is expressed by n = 0 and n = ± when expanded by exp {nΦ (x, y)} (n: integer). Given by one component. By the way, when the function f (z) represented by the following equation (13) is expanded to the Laurent series, the mathematical formula defined by the following equation (14) is established.
Here, sinc (x) = x / sin (x). Using the mathematical formula defined by the above equation (14), the phase distribution Φ (x, y) can be expanded in series, and the respective light amounts of the 0th order light and the ± 1st order light can be explained. At this time, paying attention to the fact that the absolute value of the exponent term exp {jπ (c−n)} in the above equation (14) is 1, the magnitude of the 0th-order light component of the phase distribution Φ (x, y) is It is represented by the following formula (15).
Moreover, the magnitude | size of the primary light component of phase distribution (PHI) (x, y) is represented by the following formula | equation (16).
The magnitude of the −1st order light component of the phase distribution Φ (x, y) is expressed by the following equation (17).
In the above formulas (15) to (17), the 0th-order light component and the −1st-order light component appear in addition to the primary light component except when the condition defined by the following formula (18) is satisfied. However, the magnitudes of the ± first-order light components are not equal to each other.
以上の説明では、4つの進行波の1例としてY軸正方向の進行波AUについて考えたが、他の3波(進行波AD,AR,AL)についても同様の関係が成立し、±1次光成分の大きさに差が生じる。以上の議論から、格子点Oを通り正方格子から傾斜した直線L上を異屈折率領域n04-mbが移動する軸上シフト方式によれば、±1次光成分の光量に差を与えることが原理的に可能となる。したがって、-1次光または1次光を低減して所望の光像(第1光像部分B1または第2光像部分B2)のみを選択的に取り出すことが原理的に可能になる。上述の図32(b)においても、1次光と-1次光との間に強度の差が生じていることが解る。
In the above description, the traveling wave AU in the Y-axis positive direction is considered as an example of the four traveling waves, but the same relationship holds for the other three waves (traveling waves AD, AR, AL), and ± 1 A difference occurs in the magnitude of the secondary light component. From the above discussion, according to the axial shift method in which the different refractive index region n04-mb moves on the straight line L that passes through the lattice point O and is inclined from the square lattice, it is possible to give a difference in the light amount of the ± first-order light components. It is possible in principle. Therefore, in principle, it is possible to selectively extract only a desired light image (first light image portion B1 or second light image portion B2) by reducing −1st order light or primary light. Also in FIG. 32B described above, it can be seen that there is a difference in intensity between the primary light and the −1st order light.
また、軸上シフト方式では、単位構成領域Rにおける直線Lの傾斜角θ(s軸と直線Lとのなす角度)は位相変調層n04-m内において一定であってもよい。これにより、異屈折率領域n04-mbの重心G1の配置の設計を容易に行うことができる。また、この場合、傾斜角は45°、135°、225°または315°であってもよい。これにより、正方格子に沿って進む4つの基本波(正方格子に沿ったX軸およびY軸を設定した場合、X軸正方向に進む光、X軸負方向に進む光、Y軸正方向に進む光、およびY軸負方向に進む光)が、光像に均等に寄与することができる。さらに、傾斜角θが45°、135°、225°または315°である場合、適切なバンド端モードを選択することによって、直線L上における電磁界の方向が一方向に揃うため、直線偏光を得ることができる。このようなモードの一例として上記非特許文献3のFig.3に示されているモードA、Bがある。なお、傾斜角θが0°、90°、180°または270°である場合には、4つの進行波AU,AD,AR,およびALのうち、Y軸方向またはX軸方向に進む一対の進行波が1次光(信号光)に寄与しなくなるので、信号光を高効率化することは難しい。
In the on-axis shift method, the inclination angle θ of the straight line L in the unit constituent region R (the angle formed between the s-axis and the straight line L) may be constant in the phase modulation layer n04-m. Thereby, the design of the arrangement of the center of gravity G1 of the different refractive index region n04-mb can be easily performed. In this case, the inclination angle may be 45 °, 135 °, 225 °, or 315 °. As a result, four fundamental waves traveling along the square lattice (when the X axis and the Y axis along the square lattice are set, the light traveling in the X axis positive direction, the light traveling in the X axis negative direction, and the Y axis positive direction) Traveling light and light traveling in the negative Y-axis direction) can contribute equally to the optical image. Furthermore, when the tilt angle θ is 45 °, 135 °, 225 °, or 315 °, the direction of the electromagnetic field on the straight line L is aligned in one direction by selecting an appropriate band edge mode. Obtainable. As an example of such a mode, there are modes A and B shown in FIG. When the inclination angle θ is 0 °, 90 °, 180 °, or 270 °, of the four traveling waves AU, AD, AR, and AL, a pair of progressions proceeding in the Y-axis direction or the X-axis direction. Since the waves do not contribute to the primary light (signal light), it is difficult to increase the efficiency of the signal light.
なお、活性層と位相変調層n04-mとの位置関係は、上述の回転方式と同様に、Z軸方向に沿って逆になっても、容易に光結合させることができる。
It should be noted that even if the positional relationship between the active layer and the phase modulation layer n04-m is reversed along the Z-axis direction as in the above-described rotation method, the optical coupling can be easily performed.
図37および図38は、異屈折率領域の平面形状の種々の例(軸上シフト方式)を示す図である。上述の例では、X-Y平面上における異屈折率領域n04-mbの形状が円形である。しかしながら、異屈折率領域n04-mbは円形以外の形状を有してもよい。例えば、異屈折率領域n04-mbの形状は、鏡像対称性(線対称性)を有してもよい。ここで、鏡像対称性(線対称性)とは、X-Y平面に沿った或る直線を挟んで、該直線の一方側に位置する異屈折率領域n04-mbの平面形状と、該直線の他方側に位置する異屈折率領域n04-mbの平面形状とが、互いに鏡像対称(線対称)となり得ることをいう。鏡像対称性(線対称性)を有する形状としては、例えば図37(a)に示された真円、図37(b)に示された正方形、図37(c)に示された正六角形、図37(d)に示された正八角形、図37(e)に示された正16角形、図37(f)に示された長方形、および図37(g)に示された楕円、などが挙げられる。このように、X-Y平面上における異屈折率領域n04-mbの形状が鏡像対称性(線対称性)を有する場合、位相変調層n04-mの仮想的な正方格子の単位構成領域Rそれぞれにおいて、シンプルな形状であるため、格子点Oから対応する異屈折率領域n04-mbの重心G1の方向と位置を高精度に定めることができる。すなわち、高い精度でのパターニングが可能となる。
37 and 38 are diagrams showing various examples (on-axis shift method) of the planar shape of the different refractive index regions. In the above example, the shape of the different refractive index region n04-mb on the XY plane is circular. However, the different refractive index region n04-mb may have a shape other than a circle. For example, the shape of the different refractive index region n04-mb may have mirror image symmetry (line symmetry). Here, mirror image symmetry (line symmetry) refers to the planar shape of the different refractive index region n04-mb located on one side of the straight line across a certain straight line along the XY plane, and the straight line. That the planar shape of the different refractive index region n04-mb located on the other side of each other can be mirror-image symmetric (line symmetric). As a shape having mirror image symmetry (line symmetry), for example, a perfect circle shown in FIG. 37A, a square shown in FIG. 37B, a regular hexagon shown in FIG. 37C, The regular octagon shown in FIG. 37 (d), the regular hexagon shown in FIG. 37 (e), the rectangle shown in FIG. 37 (f), the ellipse shown in FIG. 37 (g), etc. Can be mentioned. As described above, when the shape of the different refractive index region n04-mb on the XY plane has mirror image symmetry (line symmetry), each of the unit structure regions R of the virtual square lattice of the phase modulation layer n04-m Since the shape is simple, the direction and position of the center of gravity G1 of the corresponding refractive index region n04-mb from the lattice point O can be determined with high accuracy. That is, patterning with high accuracy is possible.
また、X―Y平面上における異屈折率領域n04-mbの形状は、180°の回転対称性を有さない形状であってもよい。このような形状としては、例えば図38(a)に示された正三角形、図38(b)に示された直角二等辺三角形、図38(c)に示された2つの円または楕円の一部分が重なる形状、図38(d)に示された卵型形状、図38(e)に示された涙型形状、図38(f)に示された二等辺三角形、図38(g)に示された矢印型形状、図38(h)に示された台形、図38(i)に示された5角形、図38(j)に示された2つの矩形の一部分同士が重なる形状、および図38(k)に示された2つの矩形の一部分同士が重なり且つ鏡像対称性を有さない形状、等が挙げられる。なお、卵型形状は、楕円の長軸に沿った一方の端部近傍の短軸方向の寸法が他方の端部近傍の短軸方向の寸法よりも小さくなるように変形した形状である。涙型形状は、楕円の長軸に沿った一方の端部を長軸方向に沿って突き出る尖った端部に変形した形状である。矢印型形状は、矩形の一辺が三角形状に凹みその対向する一辺が三角形状に尖った形状である。このように、X―Y平面上における異屈折率領域n04-mbの形状が180°の回転対称性を有さないことにより、より高い光出力を得ることができる。なお、異屈折率領域n04-mbは、図38(j)および図38(k)に示されたように、複数要素で構成されてもよく、この場合、異屈折率領域n04-mの重心G1は、複数の構成要素の合成重心である。
Further, the shape of the different refractive index region n04-mb on the XY plane may be a shape having no rotational symmetry of 180 °. Such shapes include, for example, an equilateral triangle shown in FIG. 38 (a), a right isosceles triangle shown in FIG. 38 (b), and a portion of two circles or ellipses shown in FIG. 38 (c). , An oval shape shown in FIG. 38 (d), a teardrop shape shown in FIG. 38 (e), an isosceles triangle shown in FIG. 38 (f), and FIG. 38 (g). Arrow shape, trapezoid shown in FIG. 38 (h), pentagon shown in FIG. 38 (i), shape in which two rectangles shown in FIG. 38 (j) overlap each other, and FIG. Examples include a shape in which a part of two rectangles shown in 38 (k) overlap with each other and has no mirror image symmetry. The oval shape is a shape deformed so that the dimension in the short axis direction near one end along the major axis of the ellipse is smaller than the dimension in the short axis direction near the other end. The teardrop shape is a shape in which one end portion along the major axis of the ellipse is deformed into a sharp end projecting along the major axis direction. The arrow-shaped shape is a shape in which one side of a rectangle is recessed in a triangular shape, and the opposite side is pointed in a triangular shape. As described above, since the shape of the different refractive index region n04-mb on the XY plane does not have a rotational symmetry of 180 °, a higher light output can be obtained. The different refractive index region n04-mb may be composed of a plurality of elements as shown in FIGS. 38 (j) and 38 (k). In this case, the center of gravity of the different refractive index region n04-m G1 is a composite centroid of a plurality of components.
図39は、異屈折率領域の平面形状の更に他の例(軸上シフト方式)を示す図である。また、図40は、図28の位相変調層の第2変形例を示す図である。
FIG. 39 is a diagram showing still another example (on-axis shift method) of the planar shape of the different refractive index region. FIG. 40 is a diagram illustrating a second modification of the phase modulation layer of FIG.
これら図39および図40に示された例では、各異屈折率領域n04-mbが複数の構成要素15b、15cで構成される。重心G1は全ての構成要素の合成重心であり、直線L上に位置する。構成要素15b、15cの双方は、基本領域n04-maの第1屈折率とは異なる第2屈折率を有する。構成要素15b、15cの双方は、空孔であってもよく、空孔に化合物半導体が埋め込まれて構成されてもよい。単位構成領域Rそれぞれにおいて、構成要素15cは、構成要素15bにそれぞれ一対一で対応して設けられる。そして、構成要素15b、15cを合わせた重心G1は、仮想的な正方格子を構成する単位構成領域Rの格子点Oを横切る直線L上に位置している。なお、何れの構成要素15b、15cも仮想的な正方格子を構成する単位構成領域Rの範囲内に含まれる。単位構成領域Rは、仮想的な正方格子の格子点間を2等分する直線で囲まれる領域となる。
In the examples shown in FIGS. 39 and 40, each of the different refractive index regions n04-mb includes a plurality of components 15b and 15c. The centroid G1 is a combined centroid of all the components and is located on the straight line L. Both the components 15b and 15c have a second refractive index different from the first refractive index of the basic region n04-ma. Both of the components 15b and 15c may be holes, or may be configured by embedding a compound semiconductor in the holes. In each unit component region R, the component 15c is provided in one-to-one correspondence with the component 15b. The center of gravity G1 obtained by combining the constituent elements 15b and 15c is located on a straight line L that crosses the lattice point O of the unit constituent region R that constitutes a virtual square lattice. Note that any of the constituent elements 15b and 15c is included within the range of the unit constituent region R that forms a virtual square lattice. The unit configuration area R is an area surrounded by a straight line that bisects the lattice points of a virtual square lattice.
構成要素15cの平面形状は例えば円形であるが、図37および図38に示された種々の例のように、様々な形状を有し得る。図39(a)~図39(k)には、X-Y平面上における構成要素15b、15cの形状および相対関係の例が示されている。図39(a)および図39(b)は、構成要素15b、15cの双方が同じ形状の図形を有する形態を示す。図39(c)および図39(d)は、構成要素15b、15cの双方が同じ形状の図形を有し、互いの一部分同士が重なる形態を示す。図39(e)は、構成要素15b、15cの双方が同じ形状の図形を有し、格子点ごとに構成要素15b、15cの重心間の距離が任意に設定された形態を示す。図39(f)は、構成要素15b、15cが互いに異なる形状の図形を有する形態を示す。図39(g)は、構成要素15b、15cが互いに異なる形状の図形を有し、格子点ごとに構成要素15b、15cの重心間の距離が任意に設定された形態を示す。
The planar shape of the component 15c is, for example, a circle, but can have various shapes as in the various examples shown in FIGS. 39 (a) to 39 (k) show examples of the shapes and relative relationships of the components 15b and 15c on the XY plane. FIG. 39A and FIG. 39B show a form in which both the components 15b and 15c have the same shape. FIG. 39 (c) and FIG. 39 (d) show a form in which both of the components 15b and 15c have the same shape and a part of each other overlaps. FIG. 39 (e) shows a form in which both the constituent elements 15b and 15c have the same shape, and the distance between the centroids of the constituent elements 15b and 15c is arbitrarily set for each lattice point. FIG. 39 (f) shows a form in which the components 15b and 15c have figures with different shapes. FIG. 39 (g) shows a form in which the constituent elements 15b and 15c have different shapes and the distance between the centroids of the constituent elements 15b and 15c is arbitrarily set for each lattice point.
また、図39(h)~図39(k)に示されたように、異屈折率用域n04-mbの一部を構成する構成要素15bは、互いに離間した2つの領域15b1、15b2により構成されてもよい。そして、領域15b1、15b2を合わせた重心(単一の構成要素15bの重心に相当)と、構成要素15cの重心との距離が格子点ごとに任意に設定されてもよい。また、この場合、図39(h)に示されたように、領域15b1、15b2および構成要素15cは、互いに同じ形状の図形を有してもよい。または、図39(i)に示されたように、領域15b1、15b2および構成要素15cのうち2つの図形が他と異なっていてもよい。また、図39(j)に示されたように、領域15b1、15b2を結ぶ直線のs軸に対する角度に加えて、構成要素15cのs軸に対する角度が各格子点ごとに任意に設定されてもよい。また、図39(k)に示されたように、領域15b1、15b2および構成要素15cが互いに同じ相対角度を維持したまま、領域15b1、15b2を結ぶ直線のs軸に対する角度が格子点ごとに任意に設定されてもよい。
Further, as shown in FIGS. 39 (h) to 39 (k), the component 15b constituting a part of the different refractive index region n04-mb is composed of two regions 15b1 and 15b2 spaced apart from each other. May be. The distance between the center of gravity of the regions 15b1 and 15b2 (corresponding to the center of gravity of the single component 15b) and the center of gravity of the component 15c may be arbitrarily set for each lattice point. In this case, as shown in FIG. 39 (h), the regions 15b1 and 15b2 and the component 15c may have figures having the same shape. Alternatively, as shown in FIG. 39 (i), two graphics in the regions 15b1 and 15b2 and the component 15c may be different from the others. Further, as shown in FIG. 39 (j), in addition to the angle with respect to the s axis of the straight line connecting the regions 15b1 and 15b2, the angle with respect to the s axis of the component 15c may be arbitrarily set for each lattice point. Good. Further, as shown in FIG. 39 (k), the angle of the straight line connecting the regions 15b1 and 15b2 with respect to the s-axis is arbitrary for each lattice point while the regions 15b1 and 15b2 and the component 15c maintain the same relative angle. May be set.
なお、異屈折率領域n04-mbの平面形状は、単位構成領域R間で互いに同一であってもよい。すなわち、異屈折率領域n04-mbが全ての単位構成領域Rにおいて同一図形を有しており、並進操作、または並進操作および回転操作により、格子点間で互いに重ね合わせることが可能であってもよい。その場合、ビーム投射パターン内におけるノイズ光およびノイズとなる0次光の発生を抑制できる。または、異屈折率領域n04-mbの平面形状は、単位構成領域R間で必ずしも同一でなくともよく、例えば図40に示されたように、隣り合う単位構成領域R間で形状が互いに異なっていてもよい。なお、図36(a)および図36(b)の例に示されたように、図37~図40の何れの場合も各格子点Oを通る直線Lの中心は格子点Oに一致するように設定されるのが好ましい。
Note that the planar shape of the different refractive index regions n04-mb may be the same between the unit constituent regions R. That is, even if the different refractive index regions n04-mb have the same figure in all the unit configuration regions R, they can be overlapped with each other between the lattice points by translation operation or translation operation and rotation operation. Good. In that case, generation of noise light and zero-order light as noise in the beam projection pattern can be suppressed. Alternatively, the planar shape of the different refractive index regions n04-mb does not necessarily have to be the same between the unit constituent regions R. For example, as shown in FIG. 40, the shapes of the adjacent unit constituent regions R are different from each other. May be. As shown in the examples of FIGS. 36A and 36B, the center of the straight line L passing through each lattice point O matches the lattice point O in any case of FIGS. Is preferably set.
上述のように、軸上シフト方式により異屈折率領域の配置パターンが決定された位相変調層の構成であっても、回転方式により異屈折率領域の配置パターンが決定された位相変調層が適用された実施形態と同様の効果を好適に奏することができる。
As described above, the phase modulation layer in which the arrangement pattern of the different refractive index region is determined by the rotation method is applied even if the arrangement pattern of the different refractive index region is determined by the on-axis shift method. The same effects as those of the embodiment described above can be suitably achieved.
100,200,300,100B…半導体発光素子、102,202,302,102B…第1クラッド層、103,203,303,103B…活性層、104,204,304,104B…位相変調層、104-m(mは正の整数),204-m,304-m,104B-m…位相変調領域、104-ma,204-ma,304-ma,104B-ma…基本領域、104-mb,204-mb,304-mb,104B-mb…複数の異屈折率領域、106,206,306,106B…第2クラッド層、108-m,208-m,308-m,108B-m…第2面側電極、110,210,310,110B-m…第1面側電極、112,212,312,112B…分離領域。
100, 200, 300, 100B ... semiconductor light emitting device, 102, 202, 302, 102B ... first cladding layer, 103, 203, 303, 103B ... active layer, 104, 204, 304, 104B ... phase modulation layer, 104- m (m is a positive integer), 204-m, 304-m, 104Bm ... phase modulation region, 104-ma, 204-ma, 304-ma, 104B-ma ... basic region, 104-mb, 204- mb, 304-mb, 104B-mb ... plurality of different refractive index regions, 106, 206, 306, 106B ... second cladding layer, 108-m, 208-m, 308-m, 108B-m ... second surface side Electrode, 110, 210, 310, 110B-m ... first surface side electrode, 112, 212, 312, 112B ... separation region.
Claims (16)
- 第1面と前記第1面に対向する第2面とを有し、前記第1面および前記第2面の一方が光を出力する光出射面として機能するとともに他方がサポート面として機能する半導体発光素子であって、
前記第1面と前記第2面との間に位置する活性層と、
前記第1面と前記第2面との間に位置し、前記活性層とそれぞれが光学的に結合される複数の位相変調領域を含む位相変調層であって、前記複数の位相変調領域それぞれが、第1屈折率を有する基本領域と、それぞれが前記基本領域内に設けられるとともに前記第1屈折率とは異なる第2屈折率を有する複数の異屈折率領域とを含む位相変調層と、
少なくとも前記活性層および前記位相変調層を含む積層構造体に対して前記第1面が配置された側に位置する第1クラッド層と、
前記積層構造体に対して前記第2面が位置する側に配置された第2クラッド層と、
前記第1クラッド層に対して前記第1面が位置する側に配置された第1面側電極と、
前記第2クラッド層に対して前記第2面が位置する側に配置された、前記複数の位相変調領域にそれぞれが対応する複数の第2面側電極であって、前記積層構造体の積層方向に沿って見たときに前記複数の位相変調領域と重なる複数の領域内にそれぞれ配置された複数の第2面側電極と、
前記第1クラッド層と前記第1面側電極との間に配置された共通基板層であって、前記複数の位相変調領域を保持する連続した面を有する共通基板層と、
を備え、
前記位相変調層に含まれる前記複数の位相変調領域それぞれにおいて、前記複数の異屈折率領域は、前記複数の第2面側電極のうち対応する第2面側電極から駆動電流が供給されたときに前記光出射面から出力される光の投射パターンであるビーム投射パターンおよび前記ビーム投射パターンが形成されるビーム投射領域を、目標ビーム投射パターンおよび目標ビーム投射領域にそれぞれ一致させるための配置パターンに従って、前記基本領域中における所定位置に配置され、
前記配置パターンは、
前記光出射面の法線方向に一致するZ軸と、前記複数の異屈折率領域を含む前記位相変調層の一方の面に一致した、互いに直交するX軸およびY軸を含むX-Y平面と、により規定されるXYZ直交座標系において、前記X-Y平面上に、それぞれが正方形状を有するM1(1以上の整数)×N1(1以上の整数)個の単位構成領域Rにより構成される仮想的な正方格子が設定されるとき、
X軸方向の座標成分x(1以上M1以下の整数)とY軸方向の座標成分y(1以上N1以下の整数)とで特定される前記X-Y平面上の単位構成領域R(x,y)において、前記単位構成領域R(x,y)内に位置する異屈折率領域の重心G1が前記単位構成領域R(x,y)の中心となる格子点O(x,y)から距離rだけ離れ、かつ、前記格子点O(x,y)から前記重心G1へのベクトルが特定方向に向くよう、規定される、
半導体発光素子。 A semiconductor having a first surface and a second surface opposite to the first surface, wherein one of the first surface and the second surface functions as a light emitting surface for outputting light and the other functions as a support surface A light emitting device,
An active layer located between the first surface and the second surface;
A phase modulation layer located between the first surface and the second surface and including a plurality of phase modulation regions each optically coupled to the active layer, each of the plurality of phase modulation regions A phase modulation layer including a basic region having a first refractive index and a plurality of different refractive index regions each having a second refractive index different from the first refractive index while being provided in the basic region;
A first cladding layer positioned on a side where the first surface is disposed with respect to a laminated structure including at least the active layer and the phase modulation layer;
A second cladding layer disposed on the side where the second surface is located with respect to the laminated structure;
A first surface side electrode disposed on a side where the first surface is located with respect to the first cladding layer;
A plurality of second surface-side electrodes respectively corresponding to the plurality of phase modulation regions, disposed on a side where the second surface is located with respect to the second cladding layer, the stacking direction of the stacked structure body A plurality of second surface side electrodes respectively disposed in a plurality of regions overlapping with the plurality of phase modulation regions when viewed along
A common substrate layer disposed between the first cladding layer and the first surface side electrode, the common substrate layer having a continuous surface holding the plurality of phase modulation regions;
With
In each of the plurality of phase modulation regions included in the phase modulation layer, when the driving current is supplied to the plurality of different refractive index regions from the corresponding second surface side electrode among the plurality of second surface side electrodes. According to the arrangement pattern for making the beam projection pattern which is the projection pattern of the light output from the light exit surface and the beam projection area where the beam projection pattern is formed match the target beam projection pattern and the target beam projection area, respectively. , Arranged at a predetermined position in the basic region,
The arrangement pattern is
An XY plane including an X-axis and a Y-axis that are orthogonal to each other and coincident with one surface of the phase modulation layer including the plurality of different refractive index regions, and a Z-axis corresponding to a normal direction of the light exit surface In the XYZ orthogonal coordinate system defined by the above, on the XY plane, each is composed of M1 (an integer greater than or equal to 1) × N1 (an integer greater than or equal to 1) unit configuration regions R each having a square shape. When a virtual square lattice is set,
The unit constituent region R (x, X, Y) on the XY plane specified by the coordinate component x (an integer between 1 and M1) in the X-axis direction and the coordinate component y (an integer between 1 and N1) in the Y-axis direction In y), the center G1 of the different refractive index region located in the unit configuration region R (x, y) is a distance from the lattice point O (x, y) that is the center of the unit configuration region R (x, y). It is defined that the vector from the lattice point O (x, y) to the centroid G1 is directed in a specific direction, separated by r.
Semiconductor light emitting device. - 前記複数の位相変調領域それぞれを電気的に分離するとともに、前記Z軸に沿った方向から見たときに前記複数の位相変調領域と重なる、前記活性層、前記第1クラッド層、および前記第2クラッド層それぞれにおける複数の対応領域を電気的に分離する分離領域を更に備える請求項1に記載の半導体発光素子。 The active layer, the first cladding layer, and the second layer that electrically isolate each of the plurality of phase modulation regions and overlap the plurality of phase modulation regions when viewed from the direction along the Z-axis. The semiconductor light emitting element according to claim 1, further comprising an isolation region that electrically isolates a plurality of corresponding regions in each of the cladding layers.
- 前記分離領域は、前記複数の位相変調領域とともに、前記活性層、前記位相変調層、前記第1クラッド層、および前記第2クラッド層それぞれにおける前記複数の対応領域を光学的に分離することを特徴とする請求項2に記載の半導体発光素子。 The separation region optically separates the plurality of corresponding regions in each of the active layer, the phase modulation layer, the first cladding layer, and the second cladding layer together with the plurality of phase modulation regions. The semiconductor light emitting device according to claim 2.
- 前記分離領域は、前記複数の位相変調領域のうち隣接する位相変調領域の間の領域において、前記第2面から前記共通基板層に向かって、前記共通基板層に到達するまで伸びており、
前記分離領域の先端と前記第1面側電極との距離は、前記共通基板層の、前記Z軸に沿った方向の厚みの半分以下であることを特徴とする請求項2または3に記載の半導体発光素子。 The separation region extends from the second surface toward the common substrate layer until reaching the common substrate layer in a region between adjacent phase modulation regions among the plurality of phase modulation regions,
The distance between the tip of the separation region and the first surface side electrode is not more than half of the thickness of the common substrate layer in the direction along the Z-axis. Semiconductor light emitting device. - 前記分離領域は、高強度光照射に起因した電場により改質された半導体層、不純物拡散またはイオン打ち込み法により絶縁化された半導体層、および、ドライエッチングまたはウェットエッチングにより形成された空気間隙のうち何れかであることを特徴とする請求項2~4の何れか一項に記載の半導体発光素子。 The isolation region includes a semiconductor layer modified by an electric field caused by high-intensity light irradiation, a semiconductor layer insulated by impurity diffusion or ion implantation, and an air gap formed by dry etching or wet etching. 5. The semiconductor light emitting device according to claim 2, wherein the semiconductor light emitting device is any one of the above.
- 前記第2面側電極の何れから駆動電流が供給された場合にも前記ビーム投射領域が等しくなるように、前記位相変調領域それぞれにおける前記配置パターンが定められている、請求項1~5の何れか一項に記載の半導体発光素子。 6. The arrangement pattern in each of the phase modulation areas is determined so that the beam projection areas are equal even when a drive current is supplied from any of the second surface side electrodes. The semiconductor light-emitting device according to claim 1.
- 前記複数の第2面側電極の何れから駆動電流が供給された場合にも前記ビーム投射パターンが等しくなるように、前記位相変調領域それぞれにおける前記配置パターンが定められている、請求項1~6の何れか一項に記載の半導体発光素子。 The arrangement pattern in each of the phase modulation regions is determined so that the beam projection pattern becomes equal when a drive current is supplied from any of the plurality of second surface side electrodes. The semiconductor light-emitting device according to any one of the above.
- 前記仮想的な正方格子の格子定数をaとするとき、前記距離rは、0≦r≦0.3aを満たし、
前記XYZ直交座標系における座標(x,y,z)が、動径の長さd1と、前記Z軸からの傾き角θtiltと、前記X-Y平面上で特定される前記X軸からの回転角θrotと、で規定される球面座標(d1,θtilt,θrot)に対して以下の式(1)~式(3)で示された関係を満たし、
前記波数空間において、Kx軸方向の座標成分kx(1以上M2以下の整数)とKy軸方向の座標成分ky(1以上N2以下の整数)とで特定される画像領域FR(kx,ky)それぞれを、前記X-Y平面上の前記単位構成領域R(x,y)に二次元逆フーリエ変換することで得られる複素振幅F(x,y)が、jを虚数単位として、以下の式(6)で与えられ、
前記位相変調層は、
前記格子点O(x,y)と前記対応する異屈折率領域の重心G1とを結ぶ線分と、前記s軸と、の成す角度φ(x,y)が、
φ(x,y)=C×P(x,y)+B
C:比例定数
B:任意定数
なる関係を満たす前記対応する異屈折率領域が前記単位構成領域R(x,y)内に配置されるよう、構成されることを特徴とする請求項1~7の何れか一項に記載の半導体発光素子。 When the lattice constant of the virtual square lattice is a, the distance r satisfies 0 ≦ r ≦ 0.3a,
The coordinates (x, y, z) in the XYZ Cartesian coordinate system are expressed in terms of the radial length d1, the tilt angle θ tilt from the Z axis, and the X axis specified on the XY plane. The rotation angle θ rot and the spherical coordinates defined by (d1, θ tilt , θ rot ) satisfy the relationship expressed by the following equations (1) to (3):
In the wave number space, an image region FR (k x, x, x ) is specified by a coordinate component k x in the Kx axis direction (an integer from 1 to M2) and a coordinate component k y in the Ky axis direction (an integer from 1 to N2) . k y ), each of which has a complex amplitude F (x, y) obtained by performing a two-dimensional inverse Fourier transform on the unit configuration region R (x, y) on the XY plane, where j is an imaginary unit, Is given by equation (6) below:
The phase modulation layer is
An angle φ (x, y) formed by a line segment connecting the lattice point O (x, y) and the centroid G1 of the corresponding different refractive index region and the s axis is
φ (x, y) = C × P (x, y) + B
C: Proportional constant B: The corresponding different refractive index region satisfying the relationship of an arbitrary constant is configured to be disposed in the unit constituent region R (x, y). The semiconductor light-emitting device according to any one of the above. - 前記XYZ直交座標系における座標(x,y,z)が、動径の長さd1と、前記Z軸からの傾き角θtiltと、前記X-Y平面上で特定される前記X軸からの回転角θrotと、で規定される球面座標(d1,θtilt,θrot)に対して以下の式(8)~式(10)で示された関係を満たし、
前記波数空間において、Kx軸方向の座標成分kx(1以上M2以下の整数)とKy軸方向の座標成分ky(1以上N2以下の整数)とで特定される画像領域FR(kx,ky)それぞれを、前記X-Y平面上の前記単位構成領域R(x,y)に二次元逆フーリエ変換することで得られる複素振幅F(x,y)が、jを虚数単位として、以下の式(13)で与えられ、
前記位相変調層は、
前記格子点O(x,y)を通る、前記s軸から傾斜した直線上に前記対応する異屈折率領域の重心G1が位置し、かつ、前記格子点O(x,y)と前記対応する異屈折率領域の重心G1までの線分長r(x,y)が、
r(x,y)=C×(P(x,y)-P0)
C:比例定数
P0:任意定数
なる関係を満たす前記対応する異屈折率領域が前記単位構成領域R(x,y)内に配置されるよう、構成されることを特徴とする請求項1~7の何れか一項に記載の半導体発光素子。 The coordinates (x, y, z) in the XYZ Cartesian coordinate system are expressed in terms of the radial length d1, the tilt angle θ tilt from the Z axis, and the X axis specified on the XY plane. The rotation angle θ rot and the spherical coordinates (d 1, θ tilt , θ rot ) defined by the following conditions (8) to (10) are satisfied,
In the wave number space, an image region FR (k x, x, x ) is specified by a coordinate component k x in the Kx axis direction (an integer from 1 to M2) and a coordinate component k y in the Ky axis direction (an integer from 1 to N2) . k y ), each of which has a complex amplitude F (x, y) obtained by performing a two-dimensional inverse Fourier transform on the unit configuration region R (x, y) on the XY plane, where j is an imaginary unit, Is given by equation (13) below,
The phase modulation layer is
A centroid G1 of the corresponding different refractive index region is located on a straight line passing through the lattice point O (x, y) and inclined from the s axis, and corresponds to the lattice point O (x, y). The line segment length r (x, y) to the center of gravity G1 of the different refractive index region is
r (x, y) = C × (P (x, y) −P 0 )
The constitution is such that the corresponding different refractive index regions satisfying a relationship of C: proportional constant P 0 : arbitrary constant are arranged in the unit constitution region R (x, y). The semiconductor light-emitting device according to any one of 7. - 前記複数の位相変調領域のうち少なくとも1つの位相変調領域において、
前記複数の異屈折率領域の全ては、前記X-Y平面上で規定される形状、前記X-Y平面上で規定される面積、および前記X-Y平面上で規定される前記距離rのうち少なくとも何れかが一致していることを特徴とする請求項1~9の何れか一項に記載の半導体発光素子。 In at least one phase modulation region of the plurality of phase modulation regions,
All of the plurality of different refractive index regions have a shape defined on the XY plane, an area defined on the XY plane, and the distance r defined on the XY plane. 10. The semiconductor light-emitting device according to claim 1, wherein at least one of them matches. - 前記複数の異屈折率領域の、前記X-Y平面上における形状は、真円、正方形、正六角形、正八角形、正16角形、正三角形、直角二等辺三角形、長方形、楕円、2つの円または楕円の一部分が重なる形状、その長軸に沿った一方の端部近傍の短軸方向の寸法が、他方の端部近傍の前記短軸方向の寸法よりも小さくなるように楕円を変形することにより得られる卵型形状、その長軸に沿った楕円の一方の端部を、長軸方向に沿って突き出る尖った端部に変形することにより得られる涙型形状、二等辺三角形、矩形の一辺が三角形の切欠き部を構成する一方、前記一辺に対向する辺が三角形の突起部を構成したな矢印型形状、台形、5角形、および、2つの矩形の一部分が重なる形状のうち何れかであることを特徴とする請求項1~10の何れか一項記載の半導体発光素子。 The shape of the plurality of different refractive index regions on the XY plane is a perfect circle, a square, a regular hexagon, a regular octagon, a regular hexagon, a regular triangle, a right isosceles triangle, a rectangle, an ellipse, two circles, or By deforming the ellipse so that a part of the ellipse overlaps, the dimension in the short axis direction near one end along the major axis is smaller than the dimension in the minor axis near the other end The oval shape obtained, one of the ellipses along the major axis is transformed into a pointed end protruding along the major axis direction, a teardrop shape, an isosceles triangle, and one side of the rectangle is While forming a triangular notch, the side opposite to the one side is any one of an arrow shape, a trapezoid, a pentagon, and a shape in which two rectangles overlap each other. What of claims 1 to 10 characterized in that The semiconductor light-emitting device of one claim or.
- 前記複数の位相変調領域のうち少なくとも1つの位相変調領域は、
前記M1×N1個の単位構成領域Rで構成された内側領域と、
前記内側領域の外周を取り囲むように設けられた外側領域であって、前記仮想的な正方格子と同一の格子構造を前記仮想的な正方格子の外周に設定することにより規定される拡張正方格子における格子点とそれぞれが重なるよう配置された複数の周辺格子点異屈折率領域を含む外側領域と、
を有することを特徴とする請求項1~11の何れか一項に記載の半導体発光素子。 At least one phase modulation region of the plurality of phase modulation regions is
An inner region composed of the M1 × N1 unit configuration regions R;
An outer region provided so as to surround the outer periphery of the inner region, and in an expanded square lattice defined by setting the same lattice structure as the virtual square lattice to the outer periphery of the virtual square lattice An outer region including a plurality of peripheral lattice point different refractive index regions arranged so as to overlap with the lattice points,
The semiconductor light-emitting device according to claim 1, comprising: - 前記複数の位相変調領域のうち少なくとも1つの位相変調領域は、
前記M1×N1個の単位構成領域Rにそれぞれ配置された複数の複数の格子点異屈折率領域であって、それぞれの重心G2が対応する単位構成領域Rの前記格子点Oに一致している複数の格子点異屈折率領域を含むことを特徴とする請求項1~12の何れか一項に記載の半導体発光素子。 At least one phase modulation region of the plurality of phase modulation regions is
A plurality of lattice point different refractive index regions respectively arranged in the M1 × N1 unit configuration regions R, and each center of gravity G2 coincides with the lattice point O of the corresponding unit configuration region R. 13. The semiconductor light emitting device according to claim 1, comprising a plurality of lattice point different refractive index regions. - 請求項1~13の何れか一項に記載の半導体発光素子を製造するための製造方法であって、
前記共通基板層を形成する第1工程と、
第3面と前記第3面に対向するとともに前記共通基板層に対面する第4面を有する素子本体を、前記共通基板層上に形成する第2工程であって、前記素子本体が、前記第3面と前記第4面との間に配置された、前記活性層、前記位相変調層、前記第1クラッド層、および前記第2クラッド層を少なくとも含み、前記位相変調層における前記基本領域が、前記複数の位相変調領域となるべき複数の部分であって、それぞれが前記複数の異屈折率領域を含む複数の部分が互いに所定距離だけ離間した状態で配置された単一層で構成される第2工程と、
少なくとも前記複数の位相変調領域となるべき複数の部分を電気的に分離する分離領域を、前記素子本体内に形成する第3工程であって、前記分離領域が、前記3面から前記第4面に向かって、前記共通基板層に到達するまで形成される第3工程と、
を備えた製造方法。 A manufacturing method for manufacturing the semiconductor light emitting device according to any one of claims 1 to 13,
A first step of forming the common substrate layer;
A second step of forming, on the common substrate layer, an element main body having a third surface and a fourth surface facing the third surface and facing the common substrate layer, wherein the element main body includes the first surface; Including at least the active layer, the phase modulation layer, the first cladding layer, and the second cladding layer disposed between a third surface and the fourth surface, wherein the basic region in the phase modulation layer includes: A plurality of portions to be the plurality of phase modulation regions, each of which includes a plurality of portions including the plurality of different refractive index regions, each of which is a single layer arranged with a predetermined distance therebetween Process,
A third step of forming in the element body a separation region for electrically separating at least a plurality of portions to be the plurality of phase modulation regions, wherein the separation region extends from the third surface to the fourth surface; A third step formed until reaching the common substrate layer,
A manufacturing method comprising: - 前記分離領域の先端と前記第1面側電極との距離は、前記共通基板層の、前記3面から前記第4面に向かう方向に沿った厚みの半分以下であることを特徴とする請求項14に記載の製造方法。 The distance between the tip of the separation region and the first surface side electrode is not more than half of the thickness of the common substrate layer along the direction from the three surfaces toward the fourth surface. 14. The production method according to 14.
- 前記分離領域は、高強度光照射に起因した電場により改質された半導体層、不純物拡散またはイオン打ち込み法により絶縁化された半導体層、および、ドライエッチングまたはウェットエッチングにより形成された空気間隙のうち何れかであることを特徴とする請求項14または15に記載の製造方法。 The isolation region includes a semiconductor layer modified by an electric field caused by high-intensity light irradiation, a semiconductor layer insulated by impurity diffusion or ion implantation, and an air gap formed by dry etching or wet etching. The manufacturing method according to claim 14, wherein the manufacturing method is any one.
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