JP2000036637A - Surface emitting laser element and surface emitting laser element array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a surely stabilized constant polarized state regardless of the temperature of a substrate, the quantity of the current injected into an active layer, etc. SOLUTION: In a surface emitting laser element 12 which is formed so that an active layer and mirror layers positioned on the under the active layer may be laminated upon another on a semiconductor substrate 10 and emits light in the direction perpendicular to the active layer, the active layer and mirror layers are formed on the inclined surface of the substrate 10 which is inclined against a plane containing the basis crystal axis of the substrate 10 and, in addition, an electrode 14 for injecting current into the active layer through the mirror layer formed on the active layer and the wiring for guiding the current to the electrode 14 are also formed on the inclined surface. In addition, the wire 16 of the wiring which is connected directly to the electrode 14 is formed in such a way that the wire 16 is long and the longitudinal direction of the wire 16 becomes nearly parallel with the direction of inclination of the inclined surface of the substrate 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a surface emitting laser device and a surface emitting laser device array, and more particularly to a surface emitting laser device and a surface emitting laser device array capable of controlling polarization.

[0002]

2. Description of the Related Art In a surface emitting laser device, since a light emitting beam is emitted perpendicularly to an active layer, polarization tends to be irregular. In particular, in order to make the light spot of the light beam emitted from the surface emitting laser element circular, if the cross-sectional structure of the optical waveguide of the surface emitting laser element is made to have a highly symmetrical shape such as a circle or a square, various polarization characteristics will be obtained for each element. Shows no control. For example, a VCSEL (vertical cavity surface emitting laser) device 100 shown in FIG. 14 is a proton-injection type VCSEL device constituting an 8 × 8 VCSEL array in which eight are arranged in each of a row direction and a column direction. 15 μm,
The exit window diameter is about 6.7 μm and the cross section is a symmetric waveguide structure with respect to the center of the exit window. In FIG. 14, reference numeral 102 denotes an upper electrode wiring connected to an upper electrode (p-type electrode), 104 denotes a bonding wire, and 106 denotes a conductor terminal. The electrode formed on the upper part of the waveguide is also square, and in such a highly symmetric configuration, each electrode corresponds to each pixel.
Figure 1 shows the polarization state of the light beam emitted from the VCSEL device.
5, various directions are shown as shown in FIG. FIG. 15, 1
6 shows the measurement results of the polarization state of each VCSEL element for two 8 × 8 VCSEL arrays. For example, it illustrates the angle of the polarization plane of the VCSEL device corresponding to the pixel P1 in FIG. 15 in theta _1.

In some cases, switching is caused by an injection current. For this reason, several methods for controlling polarization have been proposed. For example, Japanese Patent Application Laid-Open No. Hei 4-242989 proposes a method in which an electrode for injecting a current into an active layer is made anisotropic. JP-A-5-110198 proposes a method for forming a quantum well structure on a (110) substrate, and JP-A-6-302911 proposes to use an optical waveguide having a rectangular or cross structure. .

Further, IEEE Photonic technoloy lett
ers, vol.5 pp133-135 (1993), a method of applying a uniaxial stress to the (001) plane of a semiconductor substrate has been proposed by Mukaihara et al.
01) A method using an off substrate is also known (IEICE Technical Report OQE-93-104, p43-48 (1993)). Here, the off-substrate refers to a substrate cut out in a direction inclined from a reference crystal axis of a semiconductor substrate material, and the off-direction refers to the inclination direction.

[0005]

As a method for controlling the polarization of the light emitted from the surface emitting laser element, if the polarization is controlled by forming the optical waveguide in an anisotropic shape, the cross section of the light beam of the surface emitting laser element can be obtained. There is a problem that the shape may be elliptical.

As for an attempt to control the polarization by making the current density distribution anisotropic by making the electrode into which the current is injected into the active layer anisotropic, the charge injected from the electrode is then diffused. Therefore, there is a problem that a desired current density distribution cannot be maintained in the optical waveguide.

[0007] Further, in the control of polarization by the off-substrate, the use of an off-substrate causes stress in the off-direction to be generated inside the waveguide, which causes the polarization to be uniform. OQE-93-104, p43-48 (199
As can be seen in 3))), all the elements cannot be completely controlled, switching occurs in two polarization states, or the polarization directions are 90 degrees from each other and the polarizations are aligned in different directions. There is also.

Since polarized light is easily affected by various factors such as the state of the optical waveguide, the amount of current injected from the electrode, the current density distribution, and the substrate temperature, the electrode for simply injecting the current into the active layer has an anisotropic shape. Even if there is a point where polarization is controlled simply by using the off-substrate or by using the off-substrate, the change in the amount of injected current or the fluctuation of the substrate temperature will cause
Polarization characteristics tend to be unstable. For example, when the polarization characteristics of three VCSEL elements 110 formed on the off-substrate 10 as shown in FIG. 17 were measured, the polarization was not controlled. The off-substrate 10 shown in FIG. 17 is a substrate that includes the [001] direction and is inclined at −2 ° ({CAC ′ = 2}) with respect to the (100) plane as shown in FIG.
On the off-substrate 10, the wiring 114 connected to the upper electrode 112 is disposed so as to be longer in the [00-1] direction.
FIG. 19 shows the result of measuring the polarization characteristics of the VCSEL device 110.

As shown in FIGS. 19 (A), 19 (B) and 19 (C), some devices have relatively good polarization characteristics, but the polarization characteristics are different for each device. Polarization could not be controlled in all devices. The use of an off-substrate alone cannot reliably control the polarization.

The VCSEL element 110 shown in FIG.
1-1] Rectangular upper electrode (p-type electrode) 11 long in the direction
2, but the polarization characteristics did not depend at all on the longitudinal direction of the upper electrode 112 (or the direction perpendicular to the longitudinal direction).

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been developed in consideration of the above problem, and is capable of reliably obtaining a stable and constant polarization state regardless of the substrate temperature or the amount of current injected into the active layer. It is an object to provide a laser device and a surface emitting laser device array.

[0012]

According to a first aspect of the present invention, there is provided a semiconductor device having an active layer and a mirror layer located above and below the active layer. In the surface-emitting laser element formed and emitting light in a direction perpendicular to the active layer, the active layer and the mirror layer may be inclined at a predetermined angle with respect to a plane including a crystal axis that is a reference of the semiconductor substrate. An electrode formed on the inclined surface, for injecting a current into the active layer through the mirror layer formed on the active layer, and a wiring for guiding the current to the electrode are formed on the inclined surface. Wherein the wiring directly connected to the electrode among the wirings is long and formed such that its longitudinal direction substantially coincides with the inclination direction of the inclined surface.

According to a second aspect of the present invention, in the surface emitting laser element according to the first aspect, a plane including a crystal axis serving as a reference of the semiconductor substrate material is a (100) plane.

According to a third aspect of the present invention, in the surface emitting laser device according to the second aspect, the inclined surface is [00
1] is formed so as to be inclined in the range of −5 ° to + 5 ° with respect to the (100) plane with respect to the (100) plane, and the wiring directly connected to the electrode projects the [010] direction on the inclined plane. It is characterized by being formed in a long shape in the projection direction.

The invention described in claim 4 is the first to third aspects of the present invention.
In the surface emitting device according to any one of the above, a laser element region including the active layer and a mirror layer formed above and below the active layer is formed in an air post structure, and a current is injected into the active layer on an upper surface of the air post. And a wiring directly connected to the electrode is formed on a side surface of the air post via an insulating film.

According to a fifth aspect of the present invention, an active layer and a mirror layer located above and below the active layer are formed on a semiconductor substrate so that at least the active layer is formed by epitaxial growth. In a gain waveguide type surface emitting laser device which emits light in a direction perpendicular to an active layer whose current is confined by proton injection, a range of -5 ° to + 5 ° with respect to the (100) plane, including the [001] direction. A laser element region formed on an inclined surface of the semiconductor substrate inclined in the above and including the active layer and a mirror layer formed above and below the active layer is formed in an air post structure, and the active layer is formed on an upper surface of the air post. An electrode for injecting a current into the air post is formed, and a wiring for guiding a current to the electrode is provided on the side surface intersecting the [010] direction of the air post via an insulating film in the [010] direction. Is elongated in the direction of projection onto the inclined surface and is formed so as to be directly connected to the electrode.

[0017] The invention according to claim 6 is the invention according to claims 1 to 5.
A plurality of the surface emitting laser elements according to any one of the above is two-dimensionally arranged, and a matrix wiring is applied to each surface emitting element.

According to the first to fifth aspects of the present invention, the shape of the wiring directly connected to the off direction of the semiconductor substrate and the electrode for injecting current into the active layer in the vicinity of the electrode is formed to be long. In addition, since the longitudinal direction thereof and the off direction of the semiconductor substrate match, the direction in which stress occurs in the optical waveguide due to the use of the off substrate and the current density of the current injected into the optical waveguide are large. The position can be matched, and therefore the polarization can be controlled, and a stable polarization characteristic can be maintained even if the amount of current injected into the active layer or the substrate temperature changes.

According to the fourth and fifth aspects of the present invention, the laser element region is formed in an air post structure, and the wiring directly connected to the electrode for injecting current into the active layer is formed on the semiconductor substrate via the insulating film. Since it was formed so as to adhere to the side surface of the air post along the off direction, the direction in which stress is generated in the optical waveguide due to the use of the off-substrate and the effect on the air post due to the attachment of wiring to the air post act The direction coincides with the direction. As a result, the polarization is more strongly controlled, and a stable polarization characteristic can be maintained even when the amount of current injected into the active layer or the substrate temperature changes.

According to a sixth aspect of the present invention, the plurality of surface emitting laser elements obtained by the first to fifth aspects are arranged two-dimensionally. A surface emitting laser element array suitable as a light source for an image forming apparatus such as a printer, a copying machine, and an image display apparatus, which has a stable polarization characteristic with respect to fluctuations in the injection current into the active layer and fluctuations in the substrate temperature, etc. can get.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First Embodiment of the Present Invention The structure of a surface emitting laser device according to a first embodiment of the present invention will be described. First, the configuration of a surface emitting laser element array to which the present invention is applied is shown in FIG. 2, an n-GaAs substrate 10 as a semiconductor substrate is -2 [deg.] In the [010] direction with respect to a (100) plane (a plane passing through points A, B, C, and D) as shown in FIG. CAC '= 2 ゜) Off-substrate of (100) plane cut out to be inclined, and n-Ga
The inclined surface S _I of As substrate 10 on (point A, B ', C', the plane passing through the D ') is to inject current into the active layer of the laser element 01-1] direction on the inclined surface S _I An elongated upper wiring (p-type electrode wiring) 16 directly connected to the p-type electrode 14 extending in the projected projection direction (hereinafter, the projection direction is referred to as a direction before the projection for convenience). A plurality of formed surface emitting laser elements (VCSEL) 12 are formed. The upper wiring 16 is formed such that its longitudinal direction substantially coincides with the [010] direction. 3 to 5 show the structure of the surface emitting laser element array. FIG. 3 is a plan view showing a planar structure of a single surface emitting laser element in the surface emitting laser array, and FIG.
3 is a sectional view taken along line XX 'in FIG. 3, and FIG. 5 is a sectional view taken along line YY' in FIG. In these figures, an n ⁺ -GaAs buffer layer 20 is formed on an inclined surface of an n-GaAs substrate 10 by using a metal organic chemical vapor deposition (MOCVD) method.
a lower distributed Bragg reflector (DBR) mirror 22 made of n-Al _0.3 Ga _0.7 As / Al _0.9 Ga _0.1 As, and p-Al _0.3 Ga _0.7 As / Al _0.9
An upper distributed Bragg reflector (DBR) mirror 26 made of Ga _0.1 As is laminated. Between the upper DBR mirror 26 and the lower DBR mirror 22, an Al _0.6 Ga _0.4 As spacer layer 28,
8 and an active layer 24 (thickness of 90 mm formed of Al _0.12 Ga _0.88 As) in the center of the Al _0.6 Ga _0.4 As spacer layers 28, 28.
With three quantum well layers and a thickness of Al _0.3 Ga _0.7 As
A triple quantum well structure was formed with four 50-degree barrier layers. ) Are provided. Protons are injected into the upper DBR mirror 26 while leaving a 10 μm diameter region due to current constriction, thereby forming a proton injection region 30. Then from the surface n ⁺
By performing etching until reaching the -GaAs buffer layer 20, a 20 × 35 μm long air post (mesa) in the [01-1] direction is formed. After insulating the side surface of the air post with the polyimide 34, a metal to be the p-type electrode 14 is deposited. An n-type electrode 32 was formed on the entire back surface of the n-GaAs substrate 10 by vapor deposition. P-type electrode 14 formed on top
Is provided with an emission window 11 having a diameter of about 6 μm for extracting the emitted light. As shown in FIG. 3, the p-type electrode 14 has [0
10]. The p-type electrode wiring 16 is formed so as to be connected directly to the electrode pad 18 (not shown in FIG. 3; see FIG. 1). ing.

The surface emitting laser device 1 in which the longitudinal direction of the p-type electrode wiring 16 coincides with the [010] direction on the inclined surface of the off-substrate 10 inclined with respect to the [010] direction.
2 are formed. When a plurality of surface emitting laser elements 12 having such a structure were manufactured, all of the surface emitting laser elements 12 were in the off direction of the n-GaAs substrate 10 and p
Laser light linearly polarized in the [010] direction, which is the longitudinal direction of the mold electrode wiring 16, was emitted.

FIG. 6 shows the relationship between the injection current I injected from the p-type electrode 14 into the active layer 24 in the surface emitting laser element 12 and the laser output P. As shown in FIG.
The laser output characteristics were stable even when the injection current I was increased, and the polarization was completely controlled in the [010] direction.

Further, even when the substrate temperature was changed from 10 to 60 ° C., the polarization direction was constant, and switching of the polarization direction did not occur, and oscillation of light polarized in directions other than the [010] direction did not occur. Of course, the long axis direction of the p-type electrode 14 [01-
No light was emitted which coincided with [1].

According to the surface emitting laser device according to the first embodiment of the present invention, the wiring in the off direction of the semiconductor substrate and the wiring directly connected to the electrode for injecting current into the active layer have a long shape near the electrode. It is formed in the shape of a scale, and the longitudinal direction thereof is made to coincide with the off direction of the semiconductor substrate. Therefore, the direction in which stress is generated in the optical waveguide due to the use of the off substrate, and the current injected into the optical waveguide Can be made to coincide with a portion having a large current density, and therefore, the polarization is controlled, and a stable polarization characteristic can be maintained even if the amount of current injected into the active layer or the substrate temperature changes.

According to the first embodiment of the present invention,
The laser element region was formed in an air post structure, and the wiring connected directly to the electrode for injecting current into the active layer was formed so as to adhere to the side surface of the air post along the off direction of the semiconductor substrate via the insulating film. The direction in which the stress occurs in the optical waveguide due to the use of the off-substrate matches the direction in which the stress acts on the air post due to the wiring attached to the air post, and as a result, the polarization is more strongly controlled. Even if the amount of current injected into the active layer or the substrate temperature changes, stable polarization characteristics can be maintained.

In this embodiment, the surface emitting laser device having the air post structure has been described. However, the present invention is not limited to this. For example, the same effect can be obtained by applying the present invention to a surface emitting laser device having a flat structure.

Second Embodiment of the Present Invention Next, the configuration of a surface emitting laser element array according to a second embodiment of the present invention will be described. FIG. 7 shows a plan structure of a surface emitting laser element array according to the second embodiment of the present invention. 8, a GaAs substrate 10 'as a semiconductor substrate includes a [001] direction (arrow B'D' direction) and a (100) plane (points A, B,
−2 ° to the plane passing C and D) (面 CAC ′ = 2 °)
(100) semi-insulating GaAs cut out to be inclined
Of the semi-insulating substrate 10 '.
_{On I} (the plane passing through points A, B ', C', and D '), directly on the p-type electrode 14' for injecting current into the active layer of the laser device,
The long upper wiring 16 'extending in the [010] direction is formed so as to be connected. The surface emitting laser element (VCSEL) 12' thus configured is 3 × 3 in three rows and three columns.
Are formed so as to be arranged. 32 'is an n-type electrode wiring. 9 to 11 show the structure of the surface emitting laser element array. 9 is a plan view showing a planar structure of a single surface emitting laser element in the surface emitting laser array, FIG. 10 is a sectional view taken along line XX 'in FIG. 9, and FIG. 11 is a sectional view taken along line YY' in FIG. It is sectional drawing. In these figures, an n ⁺ -GaAs buffer layer 20 ′ is formed on an inclined surface of a semi-insulating substrate 10 ′ by using a metal organic chemical vapor deposition (MOCVD) method.
_{When, n-Al 0.3 Ga 0.7 As} / Al 0.9 Ga 0.1 and lower distributed Bragg reflection film (DBR) mirror 22 'consisting of _{As, p-Al 0. 3 Ga} 0.7 As
/ Al _0.9 Ga _0.1 As upper distributed Bragg reflector (DBR
) The mirror 26 'is laminated. Upper DBR mirror 26 '
And 'Between the, Al _{0. 6} Ga _0.4 As spacer layer 28' lower DBR mirror 22 'and the further Al _0.6 Ga _0.4 As spacer layer 28' 28, 28 'the active layer 24 in the central part of the' ( Al _0.12 Ga
Three quantum well layers with a thickness of _0.88 As and a thickness of 90 °
_A triple quantum well structure was formed by four barrier layers each formed of _0.3 Ga _0.7 As and having a thickness of 50 °. ). Protons are injected into the upper DBR mirror 26 'to leave a 10 μm diameter region due to current confinement, thereby forming a proton injection region. Next, etching is performed until the n ⁺ -GaAs buffer layer 20 ′ is reached from the surface to obtain a 20 × 35 μm [01-1].
A long air post (mesa) is formed on the substrate. Using the evaporation method
An n-type electrode wiring 32 'is provided in the vicinity of the air post, and the side surface of the air post is insulated with polyimide 34', and then a metal for the p-type electrode 14 'is deposited. n-type electrode wiring 32 '
Is the major axis of the air post [01-
1]. The p-type electrode 14 'formed on the air post has a thickness of about 6 μ
An emission window 11 'having an m diameter is provided. p-type electrode 14 '
Is formed so as to be connected to an electrode pad (not shown) by a p-type electrode wiring 16 'long in the [010] direction as shown in FIG.

In this manner, a surface emitting laser element in which the longitudinal direction of the p-type electrode wiring 16 'coincides with the [010] direction is formed on the off substrate 10' inclined with respect to the [010] direction. When a surface emitting laser device array having such a structure and arranged in three rows and three columns as shown in FIG. 7 was manufactured, all the surface emitting laser devices were semi-insulating substrate 10 ′.
Then, laser light linearly polarized in the [010] direction, which is the off direction of the p-type electrode wiring 16 ′, was emitted. FIGS. 12A and 12B show two surface emitting laser elements 1.
2 shows the relationship between the injection current I injected from the p-type electrode 14 'into the active layer 24' and the laser output P.

As shown in FIG. 12, the laser output characteristics of both surface emitting laser elements 12 'were stable even when the injection current I was increased, and the polarization was completely controlled in the [010] direction.

Even when the substrate temperature was changed from 10 to 60 ° C., the polarization direction was constant, and switching of the polarization direction did not occur, and oscillation of light polarized in directions other than the [010] direction did not occur. Further, the longitudinal direction of the p-type electrode 14 '[01-
No light was emitted which coincided with [1].

In the embodiment of the present invention, the off direction of the semiconductor substrate and the p-type electrode wiring direction are set to the [010] direction. However, the present invention is not limited to this. There is no problem even if the wiring direction is aligned with the [011] and [01-1] directions. In the present invention, it is important that the off direction of the semiconductor substrate coincides with the longitudinal direction of the p-type wiring for injecting current into the active layer of the surface emitting laser element.

In the first and second embodiments of the present invention, the active layer in the gain waveguide type surface emitting laser device is (1)
00) In the plane including the [001] direction with respect to the plane,
Although the off-substrate formed on the semiconductor substrate surface inclined at 2 ° has been described, the present invention is not limited to this.
0) −5 in the plane including the [001] direction with respect to the plane
The same effect was obtained when the semiconductor device was formed on a semiconductor substrate surface inclined at an angle of from + 5 ° to + 5 °.

The surface emitting laser device and the surface emitting laser array according to the present invention are also effective for structures other than those shown in the first and second embodiments. For example, the cross-sectional shape of the air post may be a symmetrical shape such as a circle or a square, and the longitudinal direction of the air post may be aligned with the off direction. This example is shown in FIG.
3 is shown. In FIG. 13, similarly to the first and second embodiments, surface light emitting devices 50 and 51 having a circular cross section and surface light emitting devices 52 having a rectangular cross section are formed on a semiconductor substrate 10 whose off direction is [010]. , 54 are formed. Upper electrode (p-type electrode) 50 of surface light emitting elements 50, 51, 52, 54
A, 51A, 52A and 54A are the semiconductor substrates 1 respectively.
Wiring 6 formed in the same [010] direction as the 0 off direction
0, 61, 62, and 63, and these wirings 60, 61, 62, and 63 are connected to the electrode pads 70, respectively.
It is connected. Each p-type electrode 50 from each electrode pad 70
A current is supplied to A, 51A, 52A, and 54A, and the current is injected into the active layer of each surface emitting laser element.

According to the second embodiment of the present invention, a plurality of surface emitting laser elements obtained by the present invention are arranged two-dimensionally, so that the surface emitting laser element A surface-emitting laser element array having stable polarization characteristics with respect to fluctuations in injection current, substrate temperature, and the like and suitable as a light source for an image forming apparatus such as a printer or a copying machine or an image display apparatus can be obtained.

[0037]

According to the first to fifth aspects of the present invention,
The shape of the wiring directly connected to the electrode for injecting current into the active layer and the off direction of the semiconductor substrate is formed in a long shape in the vicinity of the electrode, and the longitudinal direction and the off direction of the semiconductor substrate coincide with each other. Therefore, the direction in which the stress is generated in the optical waveguide due to the use of the off-substrate can be matched with the portion where the current density of the current injected into the optical waveguide is large, and therefore the polarization is controlled. Even if the amount of current injected into the active layer or the substrate temperature changes, stable polarization characteristics can be maintained.

According to the fourth and fifth aspects of the present invention, the laser element region is formed in an air post structure, and the wiring directly connected to the electrode for injecting current into the active layer is formed on the semiconductor substrate via the insulating film. Since it was formed so as to adhere to the side surface of the air post along the off direction, the direction in which stress is generated in the optical waveguide due to the use of the off-substrate and the effect on the air post due to the attachment of wiring to the air post act The direction coincides with the direction. As a result, the polarization is more strongly controlled, and a stable polarization characteristic can be maintained even when the amount of current injected into the active layer or the substrate temperature changes.

According to a sixth aspect of the present invention, a plurality of surface emitting laser elements obtained by the first to sixth aspects of the present invention are arranged two-dimensionally. A surface emitting laser element array suitable as a light source for an image forming apparatus such as a printer, a copying machine, and an image display apparatus, which has a stable polarization characteristic with respect to fluctuations in the injection current into the active layer and fluctuations in the substrate temperature, etc. can get.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a surface emitting laser device according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing an inclination direction of an off-substrate shown in FIG. 1;

FIG. 3 is a plan view showing a planar structure of the surface emitting laser device according to the first embodiment of the present invention.

FIG. 4 is a sectional view taken along line X-X ′ in FIG. 3;

FIG. 5 is a sectional view taken along line Y-Y ′ in FIG. 3;

FIG. 6 is a characteristic diagram showing a measurement example of a relationship between a laser output and an injection current into an active layer of the surface emitting laser element according to the first embodiment of the present invention.

FIG. 7 is a plan view showing a planar structure of a surface emitting laser element array according to a second embodiment of the present invention.

FIG. 8 is an explanatory view showing an inclination direction of the off-substrate shown in FIG. 7;

FIG. 9 is a plan view showing a planar structure of a single surface emitting laser element in the surface emitting laser array shown in FIG. 7;

FIG. 10 is a sectional view taken along line X-X ′ in FIG. 9;

FIG. 11 is a sectional view taken along line Y-Y ′ in FIG. 9;

FIG. 12 is a characteristic diagram showing a measurement example of a relationship between a laser output P and an injection current I injected into an active layer for two surface emitting laser elements.

FIG. 13 is a plan view showing a planar structure of a modification of the surface emitting laser element according to the present invention.

FIG. 14 is a plan view showing a specific plan configuration of a conventional surface emitting laser element array.

FIG. 15 is an explanatory view showing a measurement result of a polarization state of each surface emitting laser element of the conventional surface emitting laser element array.

FIG. 16 is an explanatory view showing a measurement result of a polarization state of each surface emitting laser element of the conventional surface emitting laser element array.

FIG. 17 is a plan view showing a planar structure of a conventional surface emitting laser element array formed on an off substrate.

FIG. 18 is an explanatory view showing an inclination direction of the off-substrate shown in FIG. 17;

FIG. 19 is a characteristic diagram showing measurement results of polarization characteristics of each surface emitting laser element of the surface emitting laser element array shown in FIG.

[Explanation of symbols]

Reference Signs List 10 n-GaAS substrate 11 emission window 12 surface emitting laser element 14 p-type electrode 16 upper wiring (wiring for p-type electrode) 18 p-type electrode pad 20 n ⁺ GaAs buffer layer 22 lower distributed Bragg reflection film (DBR) mirror 24 active Layer 26 Upper distributed Bragg reflection film (DBR) mirror 28 Spacer layer 30 Proton injection region 32 N-type wiring 34 Insulating film

Claims (6)

[Claims] An active layer is formed on a semiconductor substrate so that a mirror layer located above and below the active layer is stacked,
A surface emitting laser device that emits light in a direction perpendicular to the active layer, wherein the active layer and the mirror layer are inclined at a predetermined angle with respect to a plane including a crystal axis that is a reference of the semiconductor substrate. An electrode for injecting a current into the active layer through the mirror layer formed on the active layer, and a wiring for leading a current to the electrode are formed on the inclined surface. A surface-emitting laser element, wherein a wire directly connected to the electrode among the wires is formed in a long shape, and the longitudinal direction thereof is substantially coincident with the inclination direction of the inclined surface. 2. The semiconductor device according to claim 1, wherein a plane including a crystal axis as a reference of the semiconductor substrate material is a (100) plane.
4. The surface emitting laser device according to item 1. 3. The inclined surface is formed so as to include a [001] direction and to be inclined in a range of −5 ° to + 5 ° with respect to a (100) plane, and a wiring directly connected to the electrode is [ The surface emitting laser device according to claim 2, wherein the surface emitting laser device is formed to be elongated in a projection direction in which a [010] direction is projected onto the inclined surface. 4. A laser element region including the active layer and a mirror layer formed above and below the active layer is formed in an air post structure, and an electrode for injecting a current into the active layer is formed on an upper surface of the air post. 4. The surface emitting laser device according to claim 1, wherein a wiring directly connected to the electrode is formed on a side surface of the air post via an insulating film. 5. An active layer formed on a semiconductor substrate and a mirror layer located above and below the active layer are stacked.
At least the active layer is formed by epitaxial growth and emits light in the vertical direction of the active layer confined by proton injection. The gain waveguide type surface emitting laser element includes a [001] direction and has a (100) plane. -5 °
A laser element region formed on an inclined surface of the semiconductor substrate inclined in a range of from + 5 ° to the active region and a mirror layer formed above and below the active layer is formed in an air post structure; An electrode for injecting current into the active layer is formed on the upper surface, and [01] of the air post is formed.
A wiring for guiding a current to the electrode through an insulating film on a side surface intersecting the [0] direction is directly connected to the electrode in a long shape in a projection direction in which the [010] direction is projected onto the inclined surface. A surface emitting laser element formed on a substrate. 6. A surface-emitting laser device comprising a plurality of surface-emitting laser devices according to claim 1 arranged two-dimensionally, and each surface-emitting device provided with a matrix wiring. array.