JP2010212385A - Surface light emitting semiconductor laser, surface light emitting semiconductor laser device, optical transmitter, and information processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface light emitting semiconductor laser for stabilizing polarization. <P>SOLUTION: The surface light emitting semiconductor laser includes: an n-type GaAs substrate 100; an n-type lower DBR 102; an active region 104; a p-type current constricting layer 106; and a p-type upper DBR 108. A post P is formed from the upper DBR 108 to the lower DBR 102 on the substrate. Two recessions 110A, 110B are formed in the positions facing each other, holding an outgoing region 112 between them, in the top of the post P. Fin shapes 130 including projections/recessions are respectively formed on sidewalls on the side of the outgoing region 112 of the two recessions 110A, 110B. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a surface emitting semiconductor laser, a surface emitting semiconductor laser device, an optical transmission device, and an information processing device.

  For imager light sources such as electrophotography, an oxidized single mode surface emitting semiconductor laser (VCSEL: Vertical Cavity Surface Emitting Laser) is used. In order to maintain the single mode and stabilize the polarization in the surface emitting semiconductor laser, there is an elliptical shape or an elliptical shape in which the difference between the major axis and the minor axis of the oxidized aperture in the substrate surface is different by several microns.

  As another method of stabilizing the polarization, a method of providing a strain applying portion near the outside of the mesa as in Patent Document 1, and a method of providing an elongated opening outside the current injection region in the upper semiconductor multilayer reflective film as in Patent Document 2 , A method of adding distortion by adding shape anisotropy above the mesa portion as in Patent Document 3, and a part of the distributed feedback reflector inside the current confinement region as in Patent Document 4 parallel to the polarization direction. A method of providing a trench having a straight line portion is disclosed.

JP-A-11-54838 JP-A-2001-525995 JP 2005-86170 A JP 2006-120881 A

  An object of the present invention is to provide a surface emitting semiconductor laser capable of stabilizing polarization.

A surface-emitting type semiconductor laser according to claim 1 includes a substrate, a first semiconductor multilayer reflector of the first conductivity type formed on the substrate, and an active formed on the first semiconductor multilayer reflector. A second semiconductor multilayer reflector of the second conductivity type formed on the active region, and a concave portion is formed adjacent to the light emitting region on the upper surface of the second semiconductor multilayer reflector. An uneven portion is formed on the side wall of the recessed portion on the light emitting region side.
In Claim 2, The said recessed part is formed in multiple numbers in the position which opposes on both sides of the said light-projection area | region, and the uneven | corrugated | grooved part is formed in the side wall at the side of the said light-projection area | region of these recessed parts, respectively.
4. The second semiconductor multilayer mirror according to claim 3, wherein the second semiconductor multilayer mirror includes an AlGaAs layer having a different Al composition, and the concavo-convex portion is formed at an end portion of the AlGaAs layer having a different Al composition exposed on a side wall of the concave portion. .
In Claim 4, the said uneven | corrugated | grooved part is formed by etching the oxidation area | region of the AlGaAs layer from which the said Al composition differs.
In Claim 5, the said uneven | corrugated | grooved part is formed by selectively etching the AlGaAs layer from which the said Al composition differs.
In Claim 6, the said recessed part is covered with the insulating film.
8. The columnar structure according to claim 7, wherein a columnar structure is formed on the substrate, the columnar structure including at least a second semiconductor multilayer film reflecting mirror, and the second semiconductor multilayer film reflecting mirror including a current confinement layer including Al. The current confinement layer includes an oxidized region selectively oxidized from a side surface of the columnar structure and a conductive region surrounded by the oxidized region, and the side wall on the light emitting region side of the recess is more than the conductive region. Located outside.
A surface-emitting type semiconductor laser device according to an eighth aspect mounts the surface-emitting type semiconductor laser according to any one of the first to seventh aspects and an optical member.
According to a ninth aspect of the present invention, there is provided an optical transmission device comprising: the surface emitting semiconductor laser device according to the eighth aspect; and a transmitting unit that transmits the laser light emitted from the surface emitting semiconductor device through an optical medium.
An information processing device according to claim 10 is a surface emitting semiconductor laser device according to claim 8, a condensing unit that condenses laser light emitted from the surface emitting semiconductor laser device on a recording medium, and And a mechanism for scanning the laser beam condensed by the condensing unit on the recording medium.

According to the first aspect, the polarization can be stabilized as compared with the surface emitting semiconductor laser in which the concave and convex portion is not formed on the side wall of the concave portion adjacent to the light emitting region.
According to claim 2, it is possible to stabilize the polarized light in the direction in which the concave portion is arranged.
According to the third aspect, the uneven portion can be formed in a part of the second semiconductor multilayer film reflecting mirror.
According to the fourth aspect, the uneven portion can be formed with high accuracy.
According to the fifth aspect, the uneven portion can be formed with high accuracy.
According to the sixth aspect, the polarization is further stabilized by increasing the strain anisotropy, and the reliability is improved by protecting the concave portion.
According to the seventh aspect, the polarization of the surface emitting semiconductor laser having a columnar structure can be stabilized.
According to the eighth to tenth aspects, the surface emitting semiconductor laser device, the optical transmitting device, and the information to which the surface emitting semiconductor laser having the polarization stability and reliability improved compared to the case without the present configuration is applied. A processing device can be provided.

1 is a plan view, a cross-sectional view taken along line AA, and a cross-sectional view taken along line BB of the surface-emitting type semiconductor laser according to the first embodiment of the present invention. FIG. 2A is a plan view of a post P with the wiring metal removed, and FIG. 2B is a plan view showing another example of the wiring metal, showing a surface-emitting type semiconductor laser according to a second embodiment of the present invention. is there. FIG. 9 is a plan view of a post P in a state where a surface emitting semiconductor laser according to a third embodiment of the present invention is shown and a wiring metal is removed. It is a figure which shows the example of the etching solution for selectively etching AlGaAs. It is a schematic sectional drawing which shows the manufacturing process of the surface emitting semiconductor laser which concerns on the 1st Example of this invention. It is a schematic sectional drawing which shows the manufacturing process of the surface emitting semiconductor laser which concerns on the 1st Example of this invention. It is a figure explaining the example which forms a fin shape by the etching of the oxidation area | region of AlGaAs. It is a figure explaining the example which forms fin shape by another method. It is a schematic sectional drawing which shows the structure of the module which mounted the optical component in the surface emitting semiconductor laser which concerns on a present Example. It is a figure which shows the structural example of the information processing apparatus which uses a surface emitting semiconductor laser. It is a schematic sectional drawing which shows the structure of the optical transmission apparatus using the module shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the scale of the drawing is emphasized for clarity of the features of the invention and is not necessarily the same as the scale of the actual device.

  FIG. 1 shows a plan view of a main part of a surface-emitting type semiconductor laser according to a first embodiment of the present invention, and a cross section taken along line AA and line BB. The surface emitting semiconductor laser 10 according to the first embodiment includes an n-type lower semiconductor multilayer reflector or lower DBR (Distributed Bragg) in which AlGaAs layers having different Al compositions are alternately stacked on an n-type GaAs substrate 100. Reflector (distributed Bragg reflector) 102, active region 104, p-type AlAs current confinement layer 106 with an oxide region formed on the periphery, and p-type upper semiconductor multilayer in which AlGaAs layers having different Al compositions are alternately stacked. It is configured to include a stack of film reflectors or DBRs 108. On the substrate, the lower DBR 102 and the upper DBR 108 constitute a vertical resonator. A p-type GaAs contact layer can be formed on the uppermost layer of the upper DBR 108.

  A cylindrical post (columnar structure) P is formed on the substrate. The post P is processed into a desired shape by etching a semiconductor layer stacked on a substrate using a known photolithography process. The post P is processed from the upper DBR 108 to a part of the lower DBR 102 in the illustrated example, but the post P only needs to reach at least the current confinement layer 106. The current confinement layer 106 is oxidized a certain distance from the side wall of the post P, and has an oxidized aperture 106A that is a conductive region surrounded by the oxidized region. The size of the oxidized aperture 106A is selected so that the emitted light has a single transverse mode. For example, the diameter is less than 5 microns. The center of the post P in the axial direction is the optical axis, and laser light is emitted from the top of the post P in a direction perpendicular to the substrate.

  On the top of the post P, that is, the upper surface of the upper DBR 108, two fan-shaped recesses 110A and 110B are formed with a certain depth. The inner angles of the two recesses 110A and 110B are smaller than 90 degrees, for example, about 75 degrees, and the two recesses 110A and 110B are arranged so as to be symmetric when rotated 180 degrees with respect to the optical axis.

  A semi-cylindrical emission region 112 sandwiched between the two recesses 110A and 110B provides a laser beam emission port. The center of the cylindrical portion of the emission region 112 substantially coincides with the center of the oxidation aperture 106A, and the outer diameter of the cylindrical portion of the emission region is somewhat larger than the diameter of the oxidation aperture 106A. Further, two fan-shaped p-side electrodes 120A and 120B (plan view is indicated by hatching) are formed on the top of the post P, that is, on the upper surface of the upper DBR 108. The p-side electrodes 120A and 120B are at positions that are 180 degrees rotationally symmetric with respect to the optical axis, and the p-type electrodes 120A and 120B are disposed between the recesses 110A and 110B, respectively. The p-side electrodes 120A and 120B are ohmically connected to the uppermost p-type GaAs contact layer of the upper DBR 108.

A fin shape 130 including irregularities is formed on the side wall of the recesses 110A and 110B on the emission region 112 side. The fin shape 130 is preferably formed by etching the oxidized region of the AlGaAs layer exposed on the side walls of the recesses 110A and 110B. The enlarged view shown in FIG. 1 shows the fin shape formed in the AlGaA layer, but the interlayer insulating film 140 is omitted here. As will be described later, after the recesses 110A and 110B are formed on the tops of the posts P, the side walls of the recesses 110A and 110B are oxidized. The upper DBR 108 includes AlGaAs having a different Al composition in pairs, and the oxidation rate increases as the AlGaAs layer has a higher Al composition. Accordingly, the AlGaAs layer having a high Al composition has a longer oxidation distance from the side wall than the AlGaAs layer having a low Al composition. In this embodiment, the upper DBR 108 includes a pair of an Al _0.9 Ga _0.1 As layer having an Al composition ratio of 90% and an Al _0.15 Ga _0.85 As layer having an Al composition ratio of 15%, and is formed on the sidewalls of the recesses 110A and 110B. In this case, layers having a large oxidation distance and layers having a small oxidation distance are alternately formed, and these oxidation regions are etched by buffered hydrofluoric acid. Thereby, the fin shape 130 including the unevenness is formed on the side walls of the recesses 110A and 110B. The fin shape 130 is preferably formed on the side wall on the emission region 112 side of the recesses 110A and 110B, and increases the anisotropy of strain in the arrangement direction of the recesses 110A and 110B.

  On the substrate including the post P, an interlayer insulating film 140 made of a silicon nitride film or the like is formed. In the interlayer insulating film 140, contact holes 140A and 140B for exposing the p-side electrodes 120A and 120B at the tops of the posts P are formed. The C-shaped electrode formed at one end of the wiring electrode 150 is electrically connected to the p-side electrodes 120A and 120B through the contact holes 140A and 140B. The other end of the wiring electrode 150 is connected to an electrode pad (not shown) beyond the post P. An n-side electrode 160 is formed on the back surface of the substrate 100.

  In the surface emitting semiconductor laser of the present embodiment, two concave portions 110A and 110B are formed in one direction across the emission region 112 at the top of the post P, and AlGaAs is formed on the wall portion on the emission region 112 side of the concave portions 110A and 110B. A fin shape 130 is formed by removing a part of the layer. Formation of such recesses 110 </ b> A and 110 </ b> B can impart strain anisotropy to the post P. Further, the anisotropy of strain is increased by the fin shape 130 formed on the opposing side walls of the recesses 110A and 110B. Thereby, the stability of the polarization of the laser beam becomes more remarkable. Further, since the post P including the recesses 110A and 110B is covered with the interlayer insulating film 140, tensile or compressive stress is applied to the post P including the emission region 112 by extension or compression of the interlayer insulating film 140, and further distortion is caused. Increases anisotropy. Further, the coating with the interlayer insulating film 140 prevents the top of the post P from being exposed to the outside air or moisture, suppresses a decrease in light output, and maintains the reliability of the surface emitting semiconductor laser. Therefore, if a desired strain anisotropy is obtained, the depth of the recess (trench) does not have to be increased to the vicinity of the active layer.

  Next, a second embodiment of the present invention will be described. FIG. 2 shows a surface emitting semiconductor laser according to a second embodiment of the present invention, FIG. 2A is a plan view of the post P with the wiring metal removed, and FIG. 2B is another example of the wiring metal. FIG. In the second embodiment, the shape of the recesses 110A and 110B on the emission region 112 side is changed from a curved surface as in the first embodiment to a linear plane. As a result, the outer shape of the emission region 112 in the X-axis direction (the direction in which the concave portion is arranged) and the Y-axis direction (the direction in which the p-side electrode is arranged) are different, and strain anisotropy increases. Further, the wiring metal 150A is not limited to the C shape as in the first embodiment, but may be an annular shape as shown in FIG. 2B.

  Next, a third embodiment of the present invention will be described. FIG. 3 is a plan view of the post P, showing a surface emitting semiconductor laser according to the third embodiment of the present invention, in which the wiring metal is omitted. In the first embodiment, almost the entire top portion of the post P including the recesses 110A and 110B is uniformly covered with the interlayer insulating film. In the third embodiment, however, it extends in the direction of the p-side electrodes 120A and 120B. A strip-shaped interlayer insulating film 142 is formed. By forming such an interlayer insulating film 142, the anisotropy of strain in the direction of the recesses 110A and 110B at the top of the post P is increased. The interlayer insulating film 142 desirably has a width that covers the fin shape 130 on the side wall on the emission region 112 side of the recesses 110A and 110B. Further, in order to prevent a part of the recesses 110 </ b> A and 110 </ b> B from being exposed to the outside without being covered by the interlayer insulating film 142, another insulating protective film that covers the entire top of the post P including the interlayer insulating film 142 is provided. It is also possible to form.

  In the first to third embodiments, the recesses 110A and 110B are fan-shaped, but the shape of the recess is not limited to this, and may be a linear slit, an ellipse, an oval, or a rectangle. . In short, any shape that can give strain anisotropy in any direction at the top of the post P may be used. The interlayer insulating film covering the post P is desirably an inorganic insulating film such as SiNx. By using such an inorganic insulating film, a tensile stress can be effectively generated in the inorganic insulating film. However, this does not prevent the use of other insulating films.

Furthermore, in the above embodiment, the fin shape of the wall portions of the recesses 110A and 110B is formed by etching the oxidized region of AlGaAs. However, the present invention is not limited to this, and an etchant having selectivity with respect to the Al composition ratio is used. The walls of the recesses 110A and 110B may be etched. FIG. 4 shows an example of an etching solution having selectivity with respect to the Al composition ratio. As shown in the figure, a tartaric acid-based etchant (citric acid: hydrogen peroxide = 3: 1), a sulfuric acid system (H ₂ SO ₄ : H ₂ O ₂ : H ₂ O = 1: 1: 10), a hydrofluoric acid system (HF : NH ₃ F: H ₂ O mixed solution), a mixed solution of organic acid and hydrogen peroxide solution, hydrochloric acid, phosphoric acid, ammonia and the like can be used for the etching solution of AlGaAs.

Next, a method for manufacturing the surface emitting semiconductor laser according to the first embodiment of the present invention will be described. 5 and 6 show a manufacturing process of the AA cross section and the BB cross section shown in FIG. First, as shown in FIG. 5A, Al _0.9 Ga _0.1 As and Al _0.15 Ga _0.85 As with a carrier concentration of 2 × 10 ¹⁸ cm ⁻³ are formed on an n-type GaAs substrate 100 by metal organic chemical vapor deposition (MOCVD). N-type lower DBRs 102 are formed by alternately laminating 40.5 periods so that each film thickness becomes 1/4 of the wavelength in the medium. Furthermore, an undoped lower Al _0.6 Ga _0.4 As spacer layer and an undoped quantum well active layer (consisting of 3 layers of 70 nm GaAs quantum well layers and 4 layers of 50 nm Al _0.3 Ga _0.7 As barrier layers) An active region 104 having a thickness in the medium having a film thickness composed of an undoped upper Al _0.6 Ga _0.4 As spacer layer, a current confinement layer 106 made of p-type AlAs, and a carrier concentration of 2 × 10 ¹⁸ cm ^−. Thus, a p-type DBR 108 is formed in which ^three p-type Al _0.9 Ga _0.1 As and Al _0.15 Ga _0.85 As are alternately stacked for 30 periods so that the film thicknesses are each ¼ of the wavelength in the medium. A p-type GaAs contact layer having a carrier concentration of 1 × 10 ¹⁹ cm ⁻³ is formed on the uppermost layer of the p-type upper DBR 108. Further, as shown in the BB cross section, p-side electrodes 120A and 120B as shown in FIG. 1 are formed on the upper DBR 108 by a lift-off process. For the p-side electrodes 120A and 120, Au, Au / Ti, or the like is used. Although not described in detail here, an n-type buffer layer is formed between the substrate 100 and the lower DBR 102, or a layer in which the Al composition is changed stepwise to reduce the electrical resistance of the DBR is formed. It is also possible to do.

Next, as shown in FIG. 5B, a resist mask 200 for forming the recesses 100A and 100B is formed by patterning by a photolithography process. Reactive ion etching using a chlorine-based gas is performed through the opening of the resist mask 200 to form recesses 110 </ b> A and 110 </ b> B of about 2 to several microns in the upper DBR 108. The bottoms of the recesses 110A and 110B are either Al _0.9 Ga _0.1 As or Al _0.15 Ga _0.85 As, and Al _0.9 Ga _0.1 As and Al _0.15 Ga _0.85 As are exposed on the side walls of the recesses 110A and 110B.

  Next, after removing the resist mask 200, as shown in FIG. 5C, a resist mask 210 for forming the post P is formed. The resist mask 210 is a circular pattern that covers the recesses 110A and 110B. The semiconductor layer that is not covered with the resist mask 210 is subjected to reactive ion etching using a chlorine-based gas, and etching is performed until the lower DBR 102 is exposed. Thereby, a cylindrical post P is formed on the substrate.

Next, after removing the resist mask mask 210, as shown in FIG. 6A, the substrate is oxidized for a certain time in a steam atmosphere at 340 ° C., for example. As a result, an oxidized region oxidized by a certain distance from the side surface of the post P is formed in the current confinement layer 106, and an oxidized aperture 106A surrounded by the oxidized region is formed. The diameter of the oxidation aperture 106A is set to a size at which single transverse mode laser light is emitted, for example, 5 microns or less. Furthermore, the side walls in the upper DBR 108 exposed by the recesses 110A and 110B are simultaneously oxidized. FIG. 7A shows the state of oxidation of AlGaAs. As shown in FIG. 7A, the Al _0.9 Ga _0.1 As layer with a high Al composition ratio is oxidized from the sidewall at an oxidation distance D1, and the Al _0.15 Ga _0.85 As layer with a low Al composition ratio is oxidized at an oxidation distance D2 (D2 <D1). Oxidized oxidized regions 132 are formed on the sidewalls. However, the oxidation of the Al _0.9 Ga _0.1 As layer does not proceed to the inside of the diameter of the oxidation aperture 106A.

  Next, after forming an etching mask 220 as shown in FIG. 6B, the oxidized regions on the side walls of the recesses 110A and 110B on the emission region 112 side are etched with buffered hydrofluoric acid. FIG. 7B shows how the oxidized region is etched. As shown in FIG. 7B, the oxidized region 132 is removed from the sidewall, and irregularities having a depth corresponding to the oxidation distances D1 and D2 are formed. In this way, the fin shape 130 is formed on the opposing side walls of the recesses 110 </ b> A and 110 </ b> B exposed by the mask 220.

  Next, after the etching mask 220 is removed, as shown in FIG. 6C, a SiNx film is formed by plasma CVD, and an interlayer insulating film 140 is formed on the entire surface of the substrate including the post P. Next, contact holes 140A and 140B are formed in the interlayer insulating film 140, the p-side electrodes 120A and 120B are exposed, and then the wiring metal 150 is patterned. And after performing back surface polishing as needed, for example, an AuGe / Au n-side electrode is deposited on the back surface of the substrate.

  In the etching process of the oxidized region, the opposite side wall of the emission region 112 is exposed by the etching mask 220. However, the present invention is not limited to this, and the oxidized region of the entire side wall of the recesses 110A and 110B may be removed. Good. In this case, by forming an etching mask 220A as shown in FIG. 8 and etching the oxidized regions in the recesses 110A and 110B, fin shapes 130A and 130B are formed on the sidewalls outside the recesses 110A and 110B.

  Further, as described above, the fin shape 130 can also be formed using an etching solution having selectivity with respect to the Al composition ratio. In this case, it is not necessary to oxidize the sidewalls of the recesses 110A and 110B. Only the current confinement layer 106 is oxidized in the state shown in FIG. 5C, and then a mask 220A as shown in FIG. By using an etching solution (see FIG. 4), the sidewalls of the recesses 110A and 110B can be etched to obtain the fin shape 130 on the sidewalls.

  Next, a surface emitting semiconductor laser device, an optical transmission device, and an information processing device using the surface emitting semiconductor laser of this embodiment will be described with reference to the drawings. FIG. 9A is a cross-sectional view showing a configuration of a package (surface emitting semiconductor laser device) on which a surface emitting semiconductor laser is mounted. The package 300 fixes a chip 310 on which a surface emitting semiconductor laser is formed on a disk-shaped metal stem 330 via a conductive adhesive 320. The conductive leads 340 and 342 are inserted into through holes (not shown) formed in the stem 330, and one lead 340 is electrically connected to the n-side electrode of the surface emitting semiconductor laser, and the other The lead 342 is electrically connected to the p-side electrode.

  A rectangular hollow cap 350 is fixed on a stem 330 including the chip 310, and a ball lens 360 is fixed in an opening 352 at the center of the cap 350. The optical axis of the ball lens 360 is positioned so as to substantially coincide with the center of the chip 310. When a forward voltage is applied between the leads 340 and 342, laser light is emitted from the chip 310 in the vertical direction. The distance between the chip 310 and the ball lens 360 is adjusted so that the ball lens 360 is included within the spread angle θ of the laser light from the chip 310. Further, a light receiving element or a temperature sensor for monitoring the light emission state of the surface emitting semiconductor laser may be included in the cap.

  FIG. 9B is a diagram showing the configuration of another package. In the package 302 shown in FIG. 9B, a flat glass 362 is fixed in an opening 352 at the center of the cap 350 instead of using the ball lens 360. The center of the flat glass 362 is positioned so as to substantially coincide with the center of the chip 310. The distance between the chip 310 and the flat glass 362 is adjusted so that the opening diameter of the flat glass 362 is equal to or greater than the spread angle θ of the laser light from the chip 310.

  FIG. 10 is a diagram illustrating an example in which a surface emitting semiconductor laser is applied as a light source of an information processing apparatus. As shown in FIG. 9A or 9B, the information processing apparatus 370 includes a package 300 on which a surface emitting semiconductor laser is mounted, a collimator lens 372 that receives multi-beam laser light from the package 300, and a collimator lens that rotates at a constant speed. Reflection from the polygon mirror 374 that reflects the light beam from the 372 at a certain spread angle, the fθ lens 376 that receives the laser light from the polygon mirror 374 and irradiates the reflection mirror 378, the line-shaped reflection mirror 378, and the reflection mirror 378 A photosensitive drum 380 that forms a latent image based on light is provided. As described above, a copying machine, a printer, or the like provided with an optical system that condenses the laser light from the surface emitting semiconductor laser on the photosensitive drum and a mechanism that scans the condensed laser light on the photosensitive drum. A surface emitting semiconductor laser can be used as the light source of the information processing apparatus.

  FIG. 11 is a cross-sectional view showing a configuration when the surface-emitting type semiconductor laser device shown in FIG. 9A is applied to an optical transmitter. The optical transmission device 400 includes a cylindrical casing 410 fixed to the stem 330, a sleeve 420 integrally formed on the end surface of the casing 410, a ferrule 430 held in the opening 422 of the sleeve 420, and a ferrule 430. The optical fiber 440 to be held is included. An end of the housing 410 is fixed to a flange 332 formed in the circumferential direction of the stem 330. The ferrule 430 is accurately positioned in the opening 422 of the sleeve 420 and the optical axis of the optical fiber 440 is aligned with the optical axis of the ball lens 360. The core wire of the optical fiber 440 is held in the through hole 432 of the ferrule 430.

  The laser light emitted from the surface of the chip 310 is collected by the ball lens 360, and the collected light is incident on the core wire of the optical fiber 440 and transmitted. Although the ball lens 360 is used in the above example, other lenses such as a biconvex lens and a plano-convex lens can be used. Further, the optical transmission device 400 may include a drive circuit for applying an electrical signal to the leads 340 and 342. Furthermore, the optical transmission device 400 may include a reception function for receiving an optical signal via the optical fiber 440.

  The preferred embodiment of the present invention has been described in detail above, but the present invention is not limited to the specific embodiment, and various modifications can be made within the scope of the present invention described in the claims. Deformation / change is possible.

10: Surface emitting semiconductor laser 100: Substrate 102: Lower DBR
104: Active layer 106: Current confinement layer 106A: Oxidized aperture (conductive region)
108: upper multilayer mirrors 110A, 110B: recess 112: emission region 120A, 120B: p-side electrode 130, 130A: fin shape 140, 142: interlayer insulating film 140A, 140B: contact hole 150: wiring metal 160: n side electrode

Claims (10)

A substrate,
A first semiconductor multilayer reflector of a first conductivity type formed on a substrate;
An active region formed on the first semiconductor multilayer mirror;
A second semiconductor multilayer reflector of the second conductivity type formed on the active region,
A surface-emitting type semiconductor laser, wherein a concave portion is formed adjacent to a light emitting region on the upper surface of the second semiconductor multilayer film reflecting mirror, and a concave and convex portion is formed on a side wall of the concave portion on the light emitting region side. 2. The surface emitting semiconductor laser according to claim 1, wherein a plurality of the recesses are formed at positions facing each other with the light emission region interposed therebetween, and uneven portions are respectively formed on side walls of the plurality of recesses on the light emission region side. The second semiconductor multilayer film reflector includes an AlGaAs layer having a different Al composition, and the concavo-convex portion is formed at an end portion of the AlGaAs layer having a different Al composition exposed on a side wall of the concave portion. 2. A surface emitting semiconductor laser according to item 2. 5. The surface emitting semiconductor laser according to claim 4, wherein the concavo-convex portion is formed by etching oxidized regions of the AlGaAs layers having different Al compositions. The surface emitting semiconductor laser according to claim 4, wherein the uneven portion is formed by selectively etching the AlGaAs layers having different Al compositions. The surface emitting semiconductor laser according to claim 1, wherein the recess is covered with an insulating film. A columnar structure is formed on the substrate, and the columnar structure includes at least a second semiconductor multilayer film reflector, the second semiconductor multilayer film mirror includes a current confinement layer including Al, and the current confinement layer includes An oxide region selectively oxidized from a side surface of the columnar structure and a conductive region surrounded by the oxidized region, and the side wall on the light emission region side of the recess is located outside the conductive region. The surface emitting semiconductor laser according to claim 1. A surface-emitting semiconductor laser device comprising the surface-emitting semiconductor laser according to claim 1 and an optical member mounted thereon. 9. An optical transmission device comprising: the surface-emitting type semiconductor laser device according to claim 8; and a transmission unit that transmits laser light emitted from the surface-emitting type semiconductor device through an optical medium. A surface-emitting type semiconductor laser device according to claim 8,
Condensing means for condensing the laser light emitted from the surface-emitting type semiconductor laser device on a recording medium;
A mechanism for scanning the recording medium with the laser beam condensed by the condensing means;
An information processing apparatus.

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