JP2011243650A - Semiconductor laser element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor laser element capable of obtaining a desired shape of an outgoing beam and preventing lowering current injection efficiency.SOLUTION: The semiconductor laser element comprises a p-side electrode 113, an n-side electrode 117, an upper BDR mirror 116 composed of dielectric material, a lower DBR mirror 102, and a resonator 110 including an active layer 105. The upper BDR mirror 116, the p-side electrode 113, the resonator 110, and the lower DBR mirror 102 are disposed in this sequence, and concentric circular grooves 121, 122, and 123 forming Fresnel zone patterns are formed on a main surface of the BDR mirror 116.

Description

  The present invention relates to a semiconductor laser device, and more particularly, to a vertical cavity surface emitting semiconductor laser (VCSEL) device.

  The far field image (FFP: Far Field Pattern) of the surface emitting semiconductor laser is widened, and in order to couple the outgoing beam from the surface emitting semiconductor laser to an external optical component such as an optical fiber, in order to increase the coupling efficiency A condensing lens is used.

  In order to reduce the beam divergence angle of a far-field image of a surface emitting semiconductor laser, a technique for forming a beam shape by partially losing a semiconductor on a back semiconductor or an upper DBR reflector is disclosed (Patent Document). 1, 2, 3).

  However, in the case of forming the back surface (see Patent Documents 1 and 2), since the substrate is thinned and then processed on the back surface, there is a process difficulty, and the distance from the light emitting point to the lens is long. There have been problems such as increased aberration for each different mode, spread of light on the emission side by propagating through the semiconductor part, and influence of absorption loss of the substrate. Moreover, when forming the said layer on semiconductor DBR (refer patent document 3), since it was necessary to produce an electrode in an edge part, there existed a problem that current injection efficiency worsened.

US Pat. No. 5,073,401 US Pat. No. 6,888,871 European Patent Publication No. 2101379

  The main object of the present invention is to provide a semiconductor laser device that can obtain a desired outgoing beam shape and suppress the deterioration of current injection efficiency.

According to the present invention,
A substrate, a first DBR mirror region, an active layer, a second DBR mirror region, and an active layer for injecting current into the active layer, which are sequentially formed on the substrate, A first electrode, a second electrode on a surface side with respect to the active layer, and a current confinement layer including an opening for constricting a current injected into the active layer, and a surface opposite to the substrate A surface emitting semiconductor laser that emits laser light from
The second DBR mirror region includes a repeating structure of a pair of layers having two different refractive indexes, and
A surface-emitting type semiconductor laser in which a Fresnel zone is formed on a surface of the second DBR mirror region opposite to the substrate and a groove made of a concentric dielectric material concentric with the opening is formed. Provided.

Preferably, the boundary portion of the groove satisfies a relationship of radius Rm ² = mfλ centered on the center of the opening (Rm: radius, m: order of Fresnel zone, f: focal length, λ: wavelength). ing.

  Preferably, the layer comprises a pair of dielectric films.

Preferably, the dielectric film pair is made of SiO ₂ / SiN _x or α-Si / SiO ₂ pair.

  Preferably, the groove is formed in at least a part of the pair on the surface side of the second DBR mirror region.

Preferably, the groove has a thickness of one pair on the surface.

  According to the present invention, there is provided a laser array including a plurality of any of the semiconductor laser elements described above.

  Moreover, according to this invention, an optical apparatus provided with one of the said semiconductor laser elements or laser arrays is provided.

  According to the present invention, there is provided a communication system including any one of the above semiconductor laser elements or laser arrays.

  According to the present invention, there is provided a semiconductor laser device capable of obtaining a desired emitted beam shape and suppressing deterioration of current injection efficiency.

It is a schematic longitudinal cross-sectional view for demonstrating the semiconductor laser element of preferable 1st Embodiment of this invention. It is a figure for demonstrating the Fresnel zone plate of the semiconductor laser element of the preferable 1st and 2nd embodiment of this invention, Fig.2 (a) is a schematic plan view, FIG.2 (b) is a schematic longitudinal cross-sectional view. It is. It is a schematic longitudinal cross-sectional view for demonstrating the semiconductor laser element of preferable 2nd Embodiment of this invention. 1 is a schematic perspective view for explaining a surface emitting laser array using a plurality of surface emitting semiconductor laser elements according to preferred first and second embodiments of the present invention. FIG. It is a schematic plan view for explaining a surface emitting laser array chip using a plurality of surface emitting semiconductor laser elements according to the first and second preferred embodiments of the present invention. It is a schematic longitudinal cross-sectional view for demonstrating the surface emitting laser package using the surface emitting semiconductor laser element of the preferable 1st and 2nd embodiment of this invention. It is a schematic longitudinal cross-sectional view for demonstrating the surface emitting laser package using the surface emitting laser array which used multiple surface emitting semiconductor laser elements of the preferable 1st and 2nd embodiment of this invention. It is a schematic longitudinal cross-sectional view for demonstrating the surface emitting laser package using the surface emitting semiconductor laser element of the preferable 1st and 2nd embodiment of this invention. It is a schematic longitudinal cross-sectional view for demonstrating the pick-up for optical discs using the surface emitting semiconductor laser element of the preferable 1st and 2nd embodiment of this invention. It is a schematic plan view for demonstrating the optical transmission / reception module using the surface emitting semiconductor laser element of the preferable 1st and 2nd embodiment of this invention. Optical coupling structure of the surface emitting semiconductor laser element and the optical waveguide of the first and second preferred embodiments of the present invention, or the surface emitting semiconductor laser element of the first and second preferred embodiments of the present invention It is a schematic longitudinal cross-sectional view for demonstrating the optical coupling structure of the surface emitting laser array using two or more and an optical waveguide. Optical coupling structure of the surface emitting semiconductor laser element and the optical waveguide of the first and second preferred embodiments of the present invention, or the surface emitting semiconductor laser element of the first and second preferred embodiments of the present invention It is a schematic longitudinal cross-sectional view for demonstrating the optical coupling structure of the surface emitting laser array using two or more and an optical waveguide. Optical coupling structure of the surface emitting semiconductor laser element and the optical waveguide of the first and second preferred embodiments of the present invention, or the surface emitting semiconductor laser element of the first and second preferred embodiments of the present invention It is a schematic longitudinal cross-sectional view for demonstrating the optical coupling structure of the surface emitting laser array using two or more and an optical waveguide. A communication system using the surface emitting semiconductor laser elements of the first and second preferred embodiments of the present invention, or a plurality of surface emitting semiconductor laser elements of the first and second preferred embodiments of the present invention. It is a schematic block diagram for demonstrating the communication system using the surface emitting laser array which was used.

  Hereinafter, a surface emitting semiconductor laser element according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to these embodiments.

(First embodiment)
A semiconductor laser device 100 according to a preferred first embodiment of the present invention will be described with reference to FIG.

FIG. 1 is a schematic cross-sectional view of a surface emitting semiconductor laser element 100 according to the present embodiment. The surface emitting semiconductor laser element according to the present embodiment has a lasing wavelength in the 1100 nm band. As shown in FIG. 1, the surface emitting semiconductor laser device 100 includes a substrate 101, a lower DBR (Distributed Bragg Reflector) mirror 102 that is a lower semiconductor multilayer reflector formed on the substrate 101, and a buffer layer 103. A current confinement having an n ⁺ -type contact layer 104, an active layer 105 having a multiple quantum well structure, a current confinement portion 107a located at the outer periphery, and a circular current injection portion 107b located at the center of the current confinement portion 107a. The layer 107, the p-type cladding layer 108, and the p ⁺ -type contact layer 111 are sequentially stacked. The active layer 105 to the p ⁺ -type contact layer 111 constitute a cylindrical mesa post 130.

The substrate 101 is made of undoped GaAs. The lower DBR mirror 102 is composed of 40 pairs of GaAs / Al _0.9 Ga _0.1 As layers. The buffer layer 103 is made of undoped GaAs. The n ⁺ -type contact layer 104 is made of n ⁺ -type GaAs doped with an n-type dopant such as selenium (Se) or silicon (Si). The active layer 105 has a multiple quantum well structure in which a GaInAs well layer having 3 layers and a GaAs barrier layer having 4 layers are alternately stacked, and the lowermost GaAs barrier layer may be an n-type cladding layer. Function. In the current confinement layer 107, the current confinement portion 107a is mainly made of Al oxide, and the current injection portion 107b is made of AlAs. The radius R21 of the current injection portion 107b is 5 μm. The current confinement portion 107a restricts the path of the current flowing between the p-side annular electrode 113 and the n-side electrode 117, and the current flow is concentrated in the current injection portion 107b. It functions as a current path limiting layer.

The p-type cladding layer 108 and the p ⁺ -type contact layer 111 are made of p-type and p ⁺ -type GaAs doped with a p-type dopant such as carbon (C), zinc (Zn), or beryllium (Be), respectively. The acceptor or donor concentration of each p-type or n-type layer is, for example, about 1 × 10 ¹⁸ cm ⁻³ , and the acceptor or donor concentration of each p ⁺ -type or n ⁺ -type layer is, for example, 3 × 10 ¹⁹ cm ^−3. That's it.

on the p ⁺ -type contact layer 111 made of Ti / Pt (lower layer thereon Pt is formed by Ti structure), which has an opening 113a in the center, p-side having an outer peripheral matching the outer periphery of the mesa post 130 An annular electrode 113 is formed. The outer diameter of the p-side annular electrode 113 is, for example, 30 μm, and the inner diameter of the opening 113a is, for example, 14 μm.

  In the opening 113a of the p-side annular electrode 113, a disc-shaped dielectric layer 114 having a thickness substantially the same as that of the p-side annular electrode 113 is provided in order to provide flatness of the layer laminated thereon. Is formed. A portion from the upper surface of the dielectric layer 114 to the bottom surface of the buffer layer 103 constitutes the resonator 110.

On the p-side annular electrode 113 and the dielectric layer 114, an upper DBR mirror 116, which is an upper multilayer film reflecting mirror made of a dielectric, is formed. The upper DBR mirror 116 is made of, for example, 10 to 12 pairs of SiN _x / SiO ₂ . Further, a passivation film 145 made of SiO ₂ 143 and SiN _x 144 thereon is formed on the entire surface for surface protection. The SiO ₂ 143 and SiN _x 144 in the passivation film 145 also serve as the lowermost SiO ₂ and SiN _x in the DBR mirror 116. Therefore, in the upper DBR mirror 116 made of SiN _x / SiO ₂ , the lowermost layer is SiO ₂ 143 of the passivation film 145, and there is SiN _x 144 of the passivation film 145, on which SiO ₂ and SiN _x is alternately stacked, and the layer one layer below the top layer is SiO ₂ 128 and the top layer is SiN _x 129.

SiO ₂ 128 and SiN _x 129 are formed with concentric annular grooves 121, 122, and 123, and Fresnel zone plate 120 composed of a substantially rectangular groove is constituted by SiO ₂ 128 and SiN _x 129. .

Referring to FIG. 2, the inner radius R11 of the innermost groove 121 of the Fresnel zone plate 120 is 5 μm, and the outer radius R12 is 7.1 μm. The inner radius R13 of the outer groove 122 is 8.7 μm, and the outer radius R14 is 10.0 μm. The inner radius R15 of the outer groove 123 is 11.2 μm, and the outer radius R16 is 12.2 μm. The boundary portion of the groove provided in the Fresnel zone plate satisfies the relationship of radius Rm ² = mfλ with the center of the opening as the center (Rm: radius, m: order of Fresnel zone, f: focal length, λ: wavelength) ), A region provided between the boundary portions is a Fresnel zone (Fresnel zone).

Referring again to FIG. 1, the n ⁺ -type contact layer 104 extends radially outward from the lower portion of the mesa post 130, and has a semicircular ring formed of, for example, AuGeNi / Au (lower is AuGeNi, upper Au) on the surface. N-side electrode 117 is formed. The n-side electrode 117 has, for example, an outer diameter of 80 μm and an inner diameter of 45 μm.

  An n-side lead electrode 136 made of Au is formed so as to be in contact with the n-side electrode 117 through an opening 147 formed in the passivation film 145. On the other hand, a p-side lead electrode 135 made of Au is formed so as to contact the p-side annular electrode 113 through an opening 146 formed in the passivation film 145. The n-side electrode 117 and the p-side annular electrode 113 are electrically connected to a current supply circuit (not shown) provided outside by an n-side extraction electrode 136 and a p-side extraction electrode 135, respectively.

  The surface-emitting type semiconductor laser device 100 is connected between an n-side electrode 117 and a p-side annular electrode 113 through an n-side extraction electrode 136 and a p-side extraction electrode 135 from a current supply circuit (not shown) provided outside. When a voltage is applied, a current is supplied to the active layer 105 through the current injection unit 107b. As a result, the active layer 105 is carrier-injected and emits spontaneous emission light. Of the spontaneous emission light, light having a wavelength λ which is a laser oscillation wavelength forms a standing wave between the lower DBR mirror 102 and the upper DBR mirror 116 and is amplified by the active layer 105. When the injection current becomes equal to or greater than the threshold value, the light that forms the standing wave laser oscillates, and the 1100 nm band laser light is output from the opening 113a of the p-side annular electrode 113 and is diffracted by the Fresnel zone plate 120. And condensed.

In the present embodiment, the radius R21 of the current injection portion 107b is 5 μm, the radius R11 inside the innermost groove 121 of the Fresnel zone plate 120 is 5 μm, and is the same as the radius R21 of the current injection portion 107b. . The beam divergence angle θ ₁ of the laser beam 151 emitted from the semiconductor laser element 100 was 3 degrees. In contrast, in the case without the groove 121, 122 and 123, the beam divergence angle theta ₂ of the laser beam 152 was 10 degrees.

In this embodiment, since the radius R11 inside the innermost groove 121 of the Fresnel zone plate 120 and the radius R21 of the current injection portion 107b are the same, the light from the current injection portion 107b reaches the Fresnel zone plate 120. Then, since the beam diameter is slightly expanded, the beam expansion angle θ ₁ of the laser beam 151 is decreased due to the diffraction action by the Fresnel zone plate 120. On the other hand, since the beam diameter is somewhat widened, the equivalent reflectivity of the upper DBR mirror 116 is almost the same as when the grooves 121, 122, 123 are not provided. Further, since the Fresnel zone plate 120 is formed on the upper DBR mirror 116 outside the p-side electrode 113, it is possible to suppress the current injection efficiency from being deteriorated.

  If a structure in which the current injection point from the p-type electrode is in the resonator as in this structure is adopted, there is no need to laminate a laser shielding material such as a metal for the electrode on the upper DBR mirror. The Fresnel zone can be formed over the region where the light exists. Further, by using a dielectric material as the DBR material, vignetting due to the Fresnel zone pattern caused by the optical path shift due to the thermal lens effect can be minimized as compared with DBR using a semiconductor material such as GaAs / AlGaAs. .

  Next, a method for manufacturing the surface emitting semiconductor laser element 100 will be described.

First, the lower DBR mirror 102, the buffer layer 103, the n ⁺ -type contact layer 104, the active layer 105, the oxidized layer made of AlAs, the p-type cladding layer 108, the p ⁺ -type contact layer 111, A disk-shaped dielectric layer 114 for electrode step adjustment is selectively formed in order.

Next, a p-side annular electrode 113 made of a Ti / Pt layer is selectively formed on the p ⁺ -type contact layer 111 around the dielectric layer 114 by using a lift-off method.

Next, by using the resist pattern covering the p-side annular electrode 113 and the opening as a mask, the semiconductor layer is etched to a depth reaching the n-type contact layer 104 using an acid etching solution or the like to form a cylindrical mesa post 130 is formed in a self-aligned manner with respect to the p-side annular electrode 113, another mask is formed, and the n ⁺ -type contact layer 104 is etched to a depth reaching the buffer layer 103.

  Next, heat treatment is performed in a water vapor atmosphere to selectively oxidize the oxidized layer made of AlAs (the layer corresponding to the current confinement layer 107) from the outer peripheral side of the mesa post 130. At this time, selective oxidation occurs in the outer peripheral portion of the oxidized layer made of AlAs, and the current confinement portion 107a containing Al oxide is formed. Since the selective oxidation proceeds almost uniformly from the outer peripheral side of the layer to be oxidized made of AlAs, a current injection portion 107b made of AlAs is formed at the center. Here, the diameter of the current injection portion 107b is controlled by adjusting the heat treatment time and the like.

Next, a semi-circular n-side electrode 117 is formed on the surface of the n ⁺ -type contact layer 104 on the outer peripheral side of the mesa post 130.

Next, a passivation film 145 composed of a SiO ₂ film 143 and a SiN _x film 144 is formed on the entire surface by plasma CVD, and then an opening 147 is formed in the passivation film 145 on the n-side electrode 117 and the p-side annular electrode 113. 146 are formed, and an n-side extraction electrode 136 that contacts the n-side electrode 134 and a p-side extraction electrode 135 that contacts the p-side annular electrode 131 are formed through these openings 147 and 146, respectively.

Next, the upper DBR mirror 116 is formed using a plasma CVD method. Next, concentric annular grooves 121, 122, and 123 are formed in SiO ₂ 128 and SiN _x 129 by a photolithography technique to form a Fresnel zone plate 120 made of SiO ₂ 128 and SiN _x 129.

  Next, the back surface of the substrate 101 is polished, and the thickness of the substrate 101 is adjusted to, for example, 150 μm. Thereafter, element isolation is performed to complete the surface emitting semiconductor laser element 100 shown in FIG. According to the structure of the present application, since the Fresnel zone plate 120 is formed on the upper DBR mirror protruding from the substrate (particularly on the DBR mirror on the mesa post), the alignment with the opening of the current injection portion can be easily performed.

(Second Embodiment)
Next, a semiconductor laser device 100 according to a second preferred embodiment of the present invention will be described with reference to FIG. In the above-described first embodiment, the radius R21 of the current injection portion 107b is 5 μm, the radius R11 inside the innermost groove 121 of the Fresnel zone plate 120 is 5 μm, and the radius R21 of the current injection portion 107b. In this embodiment, the inner radius R11 of the innermost groove 121 of the Fresnel zone plate 120 is 5 μm, but the radius R22 of the current injection portion 107b is 10 μm, and the current injection portion 107b The radius R22 is different from the first embodiment in that the radius R22 is larger than the radius R11 inside the innermost groove 121 of the Fresnel zone plate 120, but the other points are the same, and the manufacturing method is also the same ( However, the basic design of the structure is the same as that of the first embodiment, and the necessary parts are increased in size). In the present embodiment, the focal length of the semiconductor laser element 100 is 40 μm, and the focal length of the semiconductor laser element 100 can be very short, and the laser beam 153 emitted from the semiconductor laser element 100 is separated from the semiconductor laser element 100 by 40 μm. To collect light. Therefore, for example, if a single mode optical fiber is positioned in the vicinity of the position, the semiconductor laser element 100 and the optical fiber can be efficiently coupled without using a condensing lens or the like.

In the above embodiment, the upper DBR mirror 116 is composed of 10-12 pairs of SiN _x / SiO _2. For example, a pair of α-Si (amorphous silicon) / SiO ₂ or α-Si / Al ₂ O ₃ is used. Depending on the refractive index of the material, the number of pairs may be such that an appropriate reflectivity of about 99% can be obtained. When configuring the upper DBR mirror 116 with a plurality pairs of α-Si / SiO ₂ is a Fresnel zone plate 120 to form a concentric annular groove 121, 122, 123 on the uppermost layer of the α-Si / SiO ₂ pairs forming a upper DBR If the mirror 116 is composed of a plurality pairs of α-Si / _Al 2 _{O 3} is concentric annular grooves 121, 122, 123 to a pair of uppermost α-Si / _Al 2 _{O 3} To form the Fresnel zone plate 120. The number of concentric annular grooves 121, 122, 123 is not limited to three and can be changed as appropriate. Further, the formation of the Fresnel zone plate 120 is not limited to the uppermost two layers, and the number of layers can be appropriately changed. However, if the Fresnel zone plate is formed by a pair of uppermost layers, the interface between layers having different compositions can be used, so that it is possible to form a Fresnel zone plate with a uniform optical length. This is most convenient because the optical length of the zone plate is λ / 2.

In the above embodiment, the layer to be oxidized is made of AlAs, but may be made of Al _1-x Ga _x As (0 <x <0.2). When the layer to be oxidized is made of Al _1-x Ga _x As, the current confinement layer is made of (Al _1-x Ga _x ) ₂ O ₃ and the current injection portion is made of Al _1-x Ga _x As. It will consist of

  As described above, a part of the dielectric DBR 116 is etched so as to have a Fresnel zone plate function, so that a surface emitting semiconductor laser element having a desired FFP (beam divergence angle) can be obtained without impairing laser characteristics. realizable. As a result, the multimode surface emitting semiconductor laser element can be easily coupled to a single mode fiber or a narrow waveguide core without using an external coupling element. In addition, a multi-mode surface-emitting semiconductor laser element arranged in two dimensions can be easily coupled to a high-density integrated organic waveguide such as a two-dimensional arrangement or a PLC (Planar Lightwave Circuit) waveguide. become.

  In the above embodiment, GaInAs / GaAs is used as the combination of the well layer / barrier layer constituting the active layer 105 of the 1100 nm band laser, but the preferred embodiment of the present invention described above depends on the wavelength (substrate And other layer configurations are appropriately selected according to the combination of the well layer and the barrier layer. InGaAs / GaAsP can be selected in the case of the laser of, and GaAs / AlGaAs in the case of the laser of 850 nm band (the combination of the well layer and the barrier layer is not limited to these). The quantum well layer and the barrier layer can be arbitrarily designed and produced in accordance with the desired wavelength to be oscillated. By appropriately changing the radii of the concentric annular grooves 121, 122, and 123 for forming the Fresnel zone plate 120 according to this wavelength, a surface emitting laser having a desired condensing characteristic can be created. It goes without saying that the substrate on which the surface emitting semiconductor laser of the present invention is laminated is appropriately selected (mainly a III-V group compound substrate) depending on conditions such as the active layer.

  Next, an example of a surface emitting laser array using a plurality of surface emitting semiconductor laser elements 100 according to a preferred embodiment of the present invention will be described with reference to FIGS. As an example, as shown in FIG. 4, a surface emitting laser array chip 700 mounted on a known flat package 710 called CLCC (Ceramic Leaded Chip Carrier) is used. In the figure, the connection between the metal caster (electrode) 714 and the surface emitting laser array chip 700 is omitted for the sake of simplicity. As shown in FIG. 5, the surface emitting laser array chip 700 includes an element portion 702 including a plurality of surface emitting semiconductor laser elements 100 provided in the center, and a plurality of light emitting portions of the element portion 702 provided around the element portion 702. And a plurality of electrode pads 706 connected (not shown). Furthermore, each electrode pad 706 is connected to a metal caster 714 of the flat package 712 (not shown). Each light emitting unit is controlled to emit light by an external control circuit (not shown) connected to the flat package 712, and emits laser light having a predetermined wavelength.

  Next, an example in which the surface emitting semiconductor laser device 100 according to the preferred embodiment of the present invention is applied to an optical apparatus will be described with reference to the drawings. FIG. 6 is a schematic longitudinal sectional view showing a configuration when the surface emitting semiconductor laser device 100 according to the preferred embodiment of the present invention is applied to a package of a light emitting device. The surface emitting laser package 300 includes a surface emitting semiconductor laser element 100, a surface emitting laser module 302 including a substrate 304 and an electrode 306, a housing 310, an optical fiber mount 312, and an optical fiber 314. The electrode 306 is electrically connected to an external control circuit (not shown), and the light emission of the surface emitting laser package is controlled. Laser light emitted from the surface emitting semiconductor laser element 100 is coupled to the optical fiber 314 without using an external condensing element such as a lens.

  Next, referring to FIG. 7, a surface emitting laser element array chip 700 having a plurality of surface emitting semiconductor laser elements 100 according to a preferred embodiment of the present invention is integrated with a high-density integrated organic waveguide 810 such as a two-dimensional array. In addition, a configuration when applied to a package of a light emitting element coupled to a PLC (Planar Lightwave Circuit) waveguide 820 will be described. The surface emitting laser package 800 includes a surface emitting laser element array chip 700, a housing 850, a waveguide mount 840, an organic waveguide 810 having a plurality of waveguides 830 in two dimensions, or a PLC waveguide 820. Laser light emitted from each surface emitting semiconductor laser element 100 of the surface emitting laser element array chip 700 is coupled to each waveguide 830 of the organic waveguide 810 or the PLC waveguide 820 without using an external condensing element such as a lens. The

  Next, another example in which the surface-emitting type semiconductor laser device 100 according to the preferred embodiment of the present invention is applied to an optical apparatus will be described with reference to the drawings. FIG. 8 is a schematic longitudinal sectional view showing a configuration when the surface emitting semiconductor laser device 100 according to the preferred embodiment of the present invention is applied to a package of the light emitting device. The surface emitting laser package 300 includes a surface emitting semiconductor laser element 100, a surface emitting laser module 302 including a substrate 304 and an electrode 306, a lens 316, a housing 310, an optical fiber mount 312, and an optical fiber 314. The electrode 306 is electrically connected to an external control circuit (not shown), and the light emission of the surface emitting laser package is controlled. Laser light emitted from the surface emitting semiconductor laser element 100 is condensed by a lens 316 and coupled to an optical fiber 314.

  FIG. 9 is a schematic longitudinal sectional view showing a configuration when the surface-emitting type semiconductor laser device 100 according to the preferred embodiment of the present invention is applied to a pickup of a writing / reading device for an optical storage medium. The pickup 350 includes a surface emitting laser module including a surface emitting semiconductor laser element 100, a substrate 354, an electrode 356, a driving IC 358, and a resin 360 that seals these elements, a lens 376, a half mirror 370, a diffraction grating 374, An optical sensor 380 and an optical storage medium 372 are included. The exit surface of the resin 360 is processed into a convex shape to constitute a lens 362. The electrode 354 is electrically connected to an external control circuit (not shown), and the light emission of the laser pickup is controlled. Laser light emitted from the surface emitting semiconductor laser element 100 is converted into parallel light by the lens 362, reflected by the half mirror 370, collected by the lens 376, and collected at a predetermined location on the optical storage medium 372. . Further, the light reflected by the optical medium is incident on the optical sensor 380. Here, the surface-emitting semiconductor laser device 100 or the surface-emitting laser device array having a plurality of surface-emitting semiconductor laser devices 100 according to the preferred embodiment of the present invention is applied to a light-emitting device package for communication or an optical disk pickup. An example is shown, but the present invention is not limited to this, and it is used as an optical instrument such as a surveying instrument, a laser pointer, an optical mouse, a printer, a light source for scanning exposure of photoresist, a laser pumping light source, a processing fiber laser light source, etc. You can also.

  FIG. 10 is a schematic configuration diagram of an optical transceiver module to which the surface emitting semiconductor laser device 100 according to the preferred embodiment of the present invention is applied. As shown in FIG. 10, the optical transceiver module 400 includes a holding member 402, an optical waveguide (optical fiber) 412, a spacer 410 for positioning the optical waveguide (optical fiber) 412 on the holding member 402, and an optical waveguide (optical fiber). ) A surface emitting semiconductor laser element 100 that transmits an optical signal via 412 or a surface emitting laser element array having a plurality of surface emitting semiconductor laser elements 100, a light receiving element 404 that receives an optical signal, and a surface emitting semiconductor laser element 100. Alternatively, the driving circuit 406 controls the light emission state of the surface emitting laser element array, and the amplifier circuit 408 amplifies the signal received by the light receiving element 404. The surface emitting semiconductor laser element 100 or the surface emitting laser element array is controlled to emit light via a drive circuit 406 by a control signal from an external control unit (not shown), and a signal received by the light receiving element 404 is amplified. Is transmitted to the control unit. In order to avoid complication, the wire bonding of the drive circuit 406 and the surface emitting semiconductor laser element 100 or the surface emitting laser element array / amplifier circuit 408 and the light receiving element 404 is omitted.

  11 to 13 are schematic configuration diagrams of an optical coupling portion between the surface emitting semiconductor laser element 100 or the surface emitting laser element array and the optical waveguide 412 in FIG. The surface emitting laser element array and the optical waveguide 412 are common in FIGS. In FIG. 11, the end surface of the waveguide 412 is processed so as to be inclined at approximately 45 degrees with respect to the optical axis. Further, this inclined surface is used as a reflecting surface 504 and is subjected to mirror surface processing such as coating of a reflecting film. Light emitted from the surface-emitting type semiconductor laser device 100 or the surface-emitting laser device array enters the waveguide from the lower surface of the waveguide 412, is reflected by the inclined surface 504, and propagates through the optical waveguide 412. In FIG. 12, on the surface emitting semiconductor laser element 100 or the surface emitting laser element array, a mirror assembly 506 having a reflecting surface 504 provided therein is provided on the side of the end face of the optical waveguide 412 so that the surface emitting semiconductor laser element is provided. The light emitted from 100 or the surface emitting laser element array is incident from the lower surface of the mirror assembly 506, reflected by the reflecting surface 504, and the light emitted from the mirror assembly 506 is coupled to the optical waveguide 412 to pass through the optical waveguide 412. Propagate. A microlens (array) may be provided on the entrance surface and / or the exit surface of the mirror assembly 506. In FIG. 13, the optical fiber 412 is disposed in the connector housing 512, and the end portion of the curved portion 514 of the optical fiber core wire is disposed so as to face the surface emitting semiconductor laser element 100 or the surface emitting laser element array. Light emitted from the surface emitting semiconductor laser element 100 or the surface emitting laser element array is coupled to the optical fiber 412.

  Next, an example in which a surface emitting laser element 100 or a surface emitting laser element array having a plurality of surface emitting semiconductor laser elements 100 according to a preferred embodiment of the present invention is applied to a communication system will be described. FIG. 14 shows a configuration example of a wavelength multiplexing transmission system using the surface emitting semiconductor laser element 100 or the surface emitting laser element array. The wavelength multiplexing transmission system of FIG. 14 includes a computer, a board or chip 602, a communication control circuit (CPU, MPU, optical-electrical conversion circuit, electrical-optical conversion circuit, wavelength control circuit) 604, and a plurality of surface emitting semiconductor laser elements 100. It includes a surface emitting laser element array 606, a light receiving element integrated unit 608, a multiplexer 610, a duplexer 612, an electrical wiring 616, optical fibers 617 and 618, a communication target network, a PC, a board, a chip, and the like 614. In the wavelength division multiplex transmission system of FIG. 14, a surface emitting laser array 606 is configured by arranging a plurality of surface emitting laser elements having different oscillation wavelengths, and each oscillation light from each surface emitting laser element of the surface emitting laser array 606 is combined. It is configured to be coupled to one optical fiber through a waver. In such a configuration, a large amount of signal can be transmitted with high throughput with a single fiber. As described above, the surface emitting laser array according to the preferred embodiment of the present invention is stable in mode and stable in each oscillation wavelength. It becomes possible. In this embodiment, the output optical fiber or the input optical fiber from each surface emitting laser array 606 or the light receiving element integrated unit 608 is coupled to one optical fiber using the multiplexer 610 or the demultiplexer 612. However, depending on the application, an output optical fiber or an input optical fiber can be directly connected to a communication target network, PC, board, chip, or the like 614 to form a parallel transmission system. In this case, since the surface emitting laser array according to the preferred embodiment of the present invention has a stable mode and each wavelength is stable, a highly reliable parallel transmission system having a plurality of light sources can be constructed. It becomes easy.

  While various typical embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Accordingly, the scope of the invention is limited only by the following claims.

DESCRIPTION OF SYMBOLS 100 Surface emitting semiconductor laser element 101 Substrate 102 Lower DBR mirror 103 Buffer layer 104 n ⁺ type contact layer 105 Active layer 107 Current confinement layer 107a Current confinement part 107b Current injection part 108 P type clad layer 110 Resonator 111 p ⁺ type contact Layer 113 p-side annular electrode 113a opening 114 dielectric layer 116 upper DBR mirror 117 n-side electrode 120 Fresnel zone plate 121, 122, 123 groove 130 mesa post 135 p-side extraction electrode 136 n-side extraction electrode 128, 143 SiO ₂ film 129, 144 SiN _x film 145 Passivation film 146, 147 Opening 151, 152, 153 Laser light

Claims (9)

A substrate, a first DBR mirror region, an active layer, a second DBR mirror region, and an active layer for injecting current into the active layer, which are sequentially formed on the substrate, A first electrode, a second electrode on a surface side with respect to the active layer, and a current confinement layer including an opening for constricting a current injected into the active layer, and a surface opposite to the substrate A surface emitting semiconductor laser that emits laser light from
The second DBR mirror region includes a repeating structure of a pair of layers having two different refractive indexes, and
A surface emitting semiconductor laser in which a Fresnel zone is formed on the surface of the second DBR mirror region opposite to the substrate, and a groove made of a concentric dielectric material concentric with the opening is formed. The boundary of the groove satisfies a relationship of radius Rm ² = mfλ centered on the center of the opening (Rm: radius, m: order of Fresnel zone, f: focal length, λ: wavelength). The surface emitting semiconductor laser according to claim 1.   3. The surface emitting semiconductor laser according to claim 1, wherein the layer is made of a pair of dielectric films. Said pairs dielectric _film, the surface-emitting type semiconductor laser according to claim 3, characterized in that it consists of SiO 2 / SiN _x or α-Si / SiO ₂ pair.   5. The surface-emitting type semiconductor laser according to claim 1, wherein the groove is formed in at least a part of the pair on the surface side of the second DBR mirror region. 5. The surface emitting semiconductor laser according to claim 2, wherein a thickness of the groove is one pair of the surfaces.   A laser array comprising a plurality of semiconductor laser elements according to claim 1.   An optical apparatus comprising the semiconductor laser element or the laser array according to any one of claims 1 to 7.   A communication system comprising the semiconductor laser element or the laser array according to any one of claims 1 to 7.

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