WO2024095620A1 - Surface emitting laser - Google Patents

Abstract

Provided is a surface emitting laser that can apply a desired loss to a transverse mode.　A surface emitting laser according to the present invention comprises an active layer, a first structure having a concave mirror disposed on one side of the active layer, and a second structure having a reflecting mirror disposed on the other side of the active layer, wherein: the first structure and/or the second structure are/is provided with a transverse mode adjustment region; when a region surrounding a light emitting region of the active layer in a plan view is defined as a first region, and a region surrounding the first region is defined as a second region, the transverse mode adjustment region has at least the first region among the first and second regions; and in a case where the transverse mode adjustment region has only the first region among the first and second regions, when the shortest distance and the longest distance, among distances from the area centroid of the transverse mode adjustment region to the inner edge of the first region, are respectively defined as D_S and D_L, 1≤D_L/D_S≤10 is established.

Description

Surface-emitting laser

The technology disclosed herein (hereinafter also referred to as "the technology") relates to a surface-emitting laser.

　Conventionally, a vertical-cavity surface-emitting laser (VCSEL) is known in which an active layer is sandwiched between first and second reflectors.

Some conventional surface-emitting lasers use a concave mirror as the first reflector and have a transverse mode adjustment region that absorbs light or disturbs the phase to cause loss in the transverse mode (see, for example, Patent Document 1). In this type of surface-emitting laser, the conditions for transverse mode adjustment are determined only by the area of the transverse mode adjustment region, etc.

International Publication No. 2018/083877

However, conventional surface-emitting lasers have room for improvement in terms of imparting the desired loss to the transverse mode.

The main objective of this technology is to provide a surface-emitting laser that can impart the desired loss to the transverse mode.

The present technology comprises an active layer and
a first structure having a concave mirror disposed on one side of the active layer;
a second structure having a reflector disposed on the other side of the active layer;
Equipped with
a transverse mode adjustment region is provided in the first structure and/or the second structure;
the transverse mode adjustment region has at least the first region of the first and second regions, when a region surrounding a light emitting region of the active layer in a plan view is defined as a first region and a region surrounded by the first region is defined as a second region,
When the transverse mode adjustment region has only the first region of the first and second regions, the shortest distance from the center of gravity of the transverse mode adjustment region to the inner edge of the first region is defined as D _S and the longest distance is defined as D _L ;
When the transverse mode adjustment region has the first and second regions, the shortest distance from the areal center of gravity of the transverse mode adjustment region to the inner edge of the first region and the outer edge of the second region is denoted by D _S and the longest distance is denoted by D _L .
A surface emitting laser in which 1≦D _L /D _S ≦10 is provided.
A current confinement region that sets the light emitting region may be provided in the first structure and/or the second structure.
The relationship 1≦D _L /D _S ≦6 may be satisfied.
The relationship 1≦D _L /D _S ≦3 may be satisfied.
The following may hold: 0.5≦D _S /ω≦6, and 0.5≦D _L /ω≦12.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius L _m : Vertical distance from the beam waist to the transverse mode adjustment region n: Refractive index of the medium λ ₀ : Oscillation wavelength of the surface emitting laser 1≦D _S /ω≦3 and 1≦D _L /ω≦12 may be satisfied.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius L _m : Vertical distance from the beam waist to the transverse mode adjustment region n: Refractive index of the medium λ ₀ : Oscillation wavelength of the surface emitting laser 0.5≦D _S /ω≦6 and 1≦D _L /ω≦6 may be satisfied.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ _0
ω0 : Beam waist radius _Lm : Vertical distance from the beam waist to the transverse mode adjustment region n: Refractive index of the medium _λ0 : Oscillation wavelength of the surface-emitting laser The second structure may have an electrode arranged on the other side of the active layer, and the electrode may have the transverse mode adjustment region.
The first structure may include an electrode disposed on the one side of the active layer, the electrode including the transverse mode tuning region.
The concave mirror may include the transverse mode adjustment region.
The reflector may have the transverse mode adjustment region.
The second structure may have the transverse mode adjustment region on a side of the reflector opposite to the active layer side.
The first structure may have the transverse mode adjustment region on a side of the concave mirror opposite to the active layer side.
The first structure may have the transverse mode adjustment region between the concave mirror and the active layer.
The second structure may have the transverse mode adjustment region between the reflector and the active layer.
The current confinement region may include the transverse mode adjustment region.
The second structure may have an insulating film disposed on the other side of the active layer, the insulating film having the transverse mode adjustment region.
The first structure may include a substrate disposed between the concave mirror and the active layer, and an intermediate layer disposed between the concave mirror and the substrate, the intermediate layer having the transverse mode adjustment region.
The first region and/or the second region may include a plurality of microstructures.
The transverse mode adjustment region may be made of any one of a metal material, an alloy material, a dielectric material, a semiconductor material, and an organic material.

1 is a cross-sectional view of a surface-emitting laser according to Example 1 of an embodiment of the present technology. 2 is a plan view of a transverse mode adjustment region of the surface emitting laser of FIG. 1. 11A and 11B are diagrams for explaining the influence of a transverse mode adjustment region on each mode. 1 is a graph showing the relationship between D _S (=D _L ) and the mode loss in the anode electrode for each mode. 2 is a flowchart for explaining an example of a method for manufacturing the surface emitting laser of FIG. 1 . 6A and 6B are cross-sectional views illustrating steps in an example of a method for manufacturing the surface-emitting laser of FIG. 7A and 7B are cross-sectional views illustrating steps in an example of a method for manufacturing the surface-emitting laser of FIG. 8A and 8B are cross-sectional views illustrating steps in an example of a method for manufacturing the surface-emitting laser of FIG. 9A and 9B are cross-sectional views illustrating steps of an example of a method for manufacturing the surface-emitting laser of FIG. 2A to 2C are cross-sectional views of steps in an example of a method for manufacturing the surface-emitting laser of FIG. 1 . Fig. 11A is a plan view of a transverse mode adjustment region of a surface-emitting laser according to Example 2 of an embodiment of the present technology, Fig. 11B is a graph showing a relationship between a radial position of light and a mode loss when the inner edge shape of the transverse mode adjustment region is substantially circular and polygonal. Fig. 12A is a plan view of a transverse mode adjustment region of a surface-emitting laser according to Example 3 of an embodiment of the present technology. Fig. 12B is a graph showing a relationship between a radial position of light and a mode loss when the inner edge shape of the transverse mode adjustment region is substantially circular and star-shaped. Fig. 13A is a plan view of a transverse mode adjustment region of a surface-emitting laser according to Example 4 of an embodiment of the present technology. Fig. 12B is a graph showing a relationship between a radial position of light and a mode loss when the inner edge shape of the transverse mode adjustment region is substantially circular and when the inner edge shape is rose-shaped. 13 is a plan view of a transverse mode adjustment region of a surface emitting laser according to Example 5 of an embodiment of the present technology. FIG. 13 is a plan view of a transverse mode adjustment region of a surface emitting laser according to Example 6 of an embodiment of the present technology. FIG. FIG. 13 is a plan view of a transverse mode adjustment region of a surface emitting laser according to Example 7 of an embodiment of the present technology. FIG. 13 is a cross-sectional view of a surface-emitting laser according to Example 8 of an embodiment of the present technology. 18 is a flowchart for explaining an example of a method for manufacturing the surface emitting laser of FIG. 17 . 19A and 19B are cross-sectional views illustrating steps in an example of a method for manufacturing the surface-emitting laser of FIG. 20A and 20B are cross-sectional views illustrating steps in an example of a method for manufacturing the surface-emitting laser of FIG. 21A and 21B are cross-sectional views illustrating each process of an example of a method for manufacturing the surface-emitting laser of FIG. 22A and 22B are cross-sectional views illustrating steps in an example of a method for manufacturing the surface-emitting laser of FIG. 18A to 18C are cross-sectional views of steps in an example of a method for manufacturing the surface-emitting laser of FIG. 17. FIG. 13 is a cross-sectional view of a surface-emitting laser according to Example 9 of an embodiment of the present technology. FIG. 13 is a cross-sectional view of a surface-emitting laser according to a tenth example of an embodiment of the present technology. 26 is a flowchart for explaining an example of a method for manufacturing the surface emitting laser of FIG. 25 . 27A and 27B are cross-sectional views illustrating steps in an example of a method for manufacturing the surface-emitting laser of FIG. FIG. 13 is a cross-sectional view of a surface-emitting laser according to an eleventh example of an embodiment of the present technology. FIG. 21 is a cross-sectional view of a surface-emitting laser according to Example 12 of an embodiment of the present technology. 30 is a flowchart for explaining an example of a method for manufacturing the surface emitting laser of FIG. 29 . 31A and 31B are cross-sectional views illustrating each step of an example of a method for manufacturing the surface-emitting laser of FIG. FIG. 23 is a cross-sectional view of a surface-emitting laser according to Example 13 of an embodiment of the present technology. 33 is a flowchart for explaining an example of a method for manufacturing the surface emitting laser of FIG. 32. FIG. 21 is a cross-sectional view of a surface-emitting laser according to Example 14 of an embodiment of the present technology. 35 is a flowchart for explaining an example of a method for manufacturing the surface emitting laser of FIG. 34. FIG. 21 is a cross-sectional view of a surface-emitting laser according to Example 15 of an embodiment of the present technology. 13 is a plan view of a transverse mode adjustment region of a surface-emitting laser according to Example 16 of an embodiment of the present technology. FIG. FIG. 21 is a cross-sectional view of a surface-emitting laser according to Example 17 of an embodiment of the present technology. 39A and 39B are plan views of a transverse mode adjustment region of a surface-emitting laser according to Example 18 and Example 19 of an embodiment of the present technology, respectively. Fig. 40A is a plan view of a transverse mode adjustment region of a surface-emitting laser according to Example 20 of an embodiment of the present technology. Fig. 40B is a plan view of a transverse mode adjustment region of a surface-emitting laser according to Example 21 of an embodiment of the present technology. 41A and 41B are plan views of a transverse mode adjustment region of a surface-emitting laser according to Example 22 and Example 23 of an embodiment of the present technology, respectively. Fig. 42A is a plan view of a transverse mode adjustment region of a surface-emitting laser according to Example 24 of an embodiment of the present technology. Fig. 42B is a plan view of a transverse mode adjustment region of a surface-emitting laser according to Example 25 of an embodiment of the present technology. 43A and 43B are plan views of a transverse mode adjustment region of a surface-emitting laser according to Example 26 and Example 27 of an embodiment of the present technology, respectively. Fig. 44A is a plan view of a transverse mode adjustment region of a surface-emitting laser according to Example 28 of an embodiment of the present technology. Fig. 43B is a plan view of a transverse mode adjustment region of a surface-emitting laser according to Example 29 of an embodiment of the present technology. Fig. 45A is a plan view of a transverse mode adjustment region of a surface-emitting laser according to Example 30 of an embodiment of the present technology. Fig. 43B is a plan view of a transverse mode adjustment region of a surface-emitting laser according to Example 31 of an embodiment of the present technology. 46A and 46B are plan views of a transverse mode adjustment region of a surface-emitting laser according to Example 32 and Example 33 of an embodiment of the present technology, respectively. FIG. 13 is a cross-sectional view of a surface-emitting laser according to Example 34 of an embodiment of the present technology. 1 is a diagram showing an example of application of a surface emitting laser according to the present technology to a distance measuring device; 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; FIG. 2 is an explanatory diagram showing an example of an installation position of a distance measuring device.

Below, a preferred embodiment of the present technology will be described in detail with reference to the attached drawings. Note that in this specification and the drawings, components having substantially the same functional configuration will be denoted with the same reference numerals to avoid repeated description. The embodiments described below are representative embodiments of the present technology, and are not intended to narrow the scope of the present technology. Even if this specification describes that the surface-emitting laser according to the present technology has multiple effects, it is sufficient that the surface-emitting laser according to the present technology has at least one effect. The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

The explanation will be given in the following order:
0. Introduction 1. Surface-emitting laser according to Example 1 of an embodiment of the present technology 2. Surface-emitting laser according to Example 2 of an embodiment of the present technology 3. Surface-emitting laser according to Example 3 of an embodiment of the present technology 4. Surface-emitting laser according to Example 4 of an embodiment of the present technology 5. Surface-emitting laser according to Example 5 of an embodiment of the present technology 6. Surface-emitting laser according to Example 6 of an embodiment of the present technology 7. Surface-emitting laser according to Example 7 of an embodiment of the present technology 8. Surface-emitting laser according to Example 8 of an embodiment of the present technology 9. Surface-emitting laser according to Example 9 of an embodiment of the present technology 10. Surface-emitting laser according to Example 10 of an embodiment of the present technology 11. Surface-emitting laser according to Example 11 of an embodiment of the present technology 12. Surface-emitting laser according to Example 12 of an embodiment of the present technology 13. Surface-emitting laser according to Example 13 of an embodiment of the present technology 14. Surface-emitting laser according to Example 14 of an embodiment of the present technology 15. Surface-emitting laser according to Example 15 of an embodiment of the present technology 16. Surface-emitting laser according to Example 16 of an embodiment of the present technology 17. Surface-emitting laser according to Example 17 of an embodiment of the present technology 18. Surface-emitting laser 19 according to Example 18 of one embodiment of the present technology. Surface-emitting laser 20 according to Example 19 of one embodiment of the present technology. Surface-emitting laser 21 according to Example 21 of one embodiment of the present technology. Surface-emitting laser 22 according to Example 22 of one embodiment of the present technology. Surface-emitting laser 23 according to Example 23 of one embodiment of the present technology. Surface-emitting laser 24 according to Example 24 of one embodiment of the present technology. Surface-emitting laser 25 according to Example 25 of one embodiment of the present technology. Surface-emitting laser 26 according to Example 26 of one embodiment of the present technology. Surface-emitting laser 27 according to Example 27 of one embodiment of the present technology. Surface-emitting laser 28 according to Example 28 of one embodiment of the present technology. Surface-emitting laser 29 according to Example 29 of one embodiment of the present technology. Surface-emitting laser 30 according to Example 30 of one embodiment of the present technology. Surface-emitting laser 31 according to Example 31 of one embodiment of the present technology. Surface-emitting laser 32 according to Example 32 of one embodiment of the present technology. Surface-emitting laser 33 according to Example 33 of one embodiment of the present technology. Surface emitting laser according to Example 34 of an embodiment of the present technology 35. Modification of the present technology 36. Application example to electronic devices 37. Example of application of surface emitting laser to distance measurement device 38. Example of mounting distance measurement device on a moving body

<0. Introduction>
In the conventional technology, the mode loss effect region as a transverse mode adjustment region is defined as a region that acts to increase or decrease the loss of the oscillation mode by absorbing light or disturbing the phase (see, for example, International Publication No. 2018/083877). In this conventional technology, when the area of the orthogonal projection image of the current injection region (light emitting region) is S1 and the area inside the mode loss effect region is S2, the condition for transverse mode adjustment is to satisfy 0.01≦S1/(S1+S2)≦0.7.

As such, in conventional technology, the conditions for transverse mode adjustment are specified only in terms of the area of the mode loss effect region, etc., with no mention of distance whatsoever.

The inventors discovered that while the manner of laser oscillation is roughly determined by the size of the area, in order to more appropriately adjust the transverse mode, it is necessary to control the distance to give the desired loss to the transverse mode. Specifically, the inventors discovered that the transverse beam profile of a surface-emitting laser is generally circular or nearly circular, and that the effect (degree) of loss on the transverse mode is determined by the length of the distance from the center of gravity of the beam intensity to the inside of the mode loss effect region.

Based on this new knowledge, the inventors developed a surface-emitting laser according to this technology that can impart the desired loss to the transverse mode.

Below, an embodiment of a surface-emitting laser according to the present technology will be described in detail with reference to several examples. For convenience, the upper side in the cross-sectional view of FIG. 1 and the like will be referred to as the upper side and the lower side as the lower side.

1. Surface-emitting laser according to Example 1 of an embodiment of the present technology
Hereinafter, a surface emitting laser according to a first example of an embodiment of the present technology will be described with reference to the drawings.

<Configuration of surface-emitting laser>
(overall structure)
Fig. 1 is a cross-sectional view of a surface-emitting laser according to a first embodiment of the present disclosure, Fig. 2 is a plan view of a transverse mode adjustment region of the surface-emitting laser of Fig. 1 .

The surface-emitting laser 11 is a vertical-cavity surface-emitting laser (VCSEL), as described in detail below.

As an example, as shown in FIG. 1, the surface-emitting laser 11 includes an active layer 101, a first structure ST1 having a concave mirror 102 arranged on one side (lower side) of the active layer 101, and a second structure ST2 having a reflecting mirror 103 arranged on the other side (upper side) of the active layer 101.

In other words, the surface-emitting laser 11 has a vertical resonator structure in which the active layer 101 is disposed between a concave mirror 102 and a reflecting mirror 103 that are stacked on top of each other.

The first structure ST1 further includes, as an example, a substrate 104 disposed between the active layer 101 and the concave mirror 102. As an example, the substrate 104 is provided with a cutout-shaped electrode installation portion 104b. A cathode electrode 109 is provided on the electrode installation portion 104b.

The second structure ST2, as an example, further includes a cladding layer 105 disposed between the active layer 101 and the reflector 103.

The second structure ST2, for example, further includes a transparent conductive film 106 disposed between the cladding layer 105 and the reflector 103, and a ring-shaped insulating film 107 provided on the cladding layer 105 so as to surround the center of the transparent conductive film 106. For example, the outer periphery of the transparent conductive film 106 is located on the inner periphery of the insulating film 107.

The second structure ST2, as an example, further includes a ring-shaped anode electrode 108 provided across the transparent conductive film 106 and the insulating film 107 so as to surround the light-emitting area LA in a plan view. That is, the anode electrode 108 is disposed on the other side (upper side) of the active layer 101. The anode electrode 108 and a portion of the transparent conductive film 106 corresponding to the opening 108a of the anode electrode 108 are covered by the reflector 103.

In the surface-emitting laser 11, as an example, the active layer 101, the cladding layer 105, and the peripheral region of the upper part of the substrate 104 form an ion implantation region IIA as a current confinement region. The ion implantation region IIA defines the light-emitting region LA (current injection region) of the active layer 101.

The first structure ST1 and/or the second structure ST2 are provided with a transverse mode adjustment area TMAA (Transverse Mode Adjustment Area). Here, as an example, the transverse mode adjustment area TMAA is provided in the anode electrode 108.

The cavity length of the surface-emitting laser 11, i.e., the distance between the concave mirror 102 and the reflector 103, is preferably 50 μm or less. If the cavity length is made 50 μm or more, there are disadvantages such as increased optical loss in the substrate 104 (e.g., a GaN substrate) and a smaller longitudinal mode spacing that makes mode hopping more likely to occur.

(Active layer)
The active layer 101 has, for example, a five-fold multiple quantum well structure in which In _0.04 Ga _0.96 N layers (barrier layers) and In _0.16 Ga _0.84 N layers (well layers) are stacked. The active layer 101 is also called a "light emitting layer."

(Substrate)

The substrate 104 is an n-type semiconductor substrate, for example an n-GaN substrate. The substrate 104 has a convex structure 104a corresponding to the concave mirror 102 on the surface (lower surface) facing the concave mirror 102.

(concave mirror)
The concave mirror 102 has a positive power and can reflect light from the active layer 101 and focus it near the active layer 101. This makes it possible to obtain a gain required for laser oscillation with high efficiency. FIG. 1 and other figures show reflected light RL, which is light from the active layer 101 and reflected by the concave mirror 102. Here, the distance between the active layer 101 and the concave mirror 102 and the radius of curvature of the concave mirror 102 are set so that the beam waist of the reflected light RL is located within the active layer 101.

As an example, the reflectance of concave mirror 102 is set to be slightly higher than that of reflecting mirror 103. In other words, reflecting mirror 103 is the reflecting mirror on the emission side. Note that the reflectance of concave mirror 102 may be set to be slightly higher than that of reflecting mirror 103, and concave mirror 102 may be used as the reflecting mirror on the emission side.

The concave mirror 102 is provided along the convex structure 104a of the substrate 104. In other words, the concave mirror 102 has a shape that follows the convex structure 104a.

The concave mirror 102 is, for example, a dielectric multilayer reflector made of, for example, _Ta2O5 / _SiO2 , _SiO2 /SiN, _{or SiO2} / _{Nb2O5 .}

(Cathode Electrode)
The cathode electrode 109 is made of at least one metal (including alloy) selected from the group consisting of Au, Ag, Pd, Pt, Ni, Ti, V, W, Cr, Al, Cu, Zn, Sn, and In. When the cathode electrode 109 has a laminated structure, it is made of materials such as Ti/Au, Ti/Al, Ti/Al/Au, Ti/Pt/Au, Ni/Au, Ni/Au/Pt, Ni/Pt, Pd/Pt, Ag/Pd, etc. The cathode electrode 109 is connected to the cathode (negative electrode) of the laser driver.

(Reflector)
The reflecting mirror 103 includes, as an example, a plane mirror. The reflecting mirror 103 has a stepped structure in which a central portion that substantially functions as a plane mirror is disposed within the opening 108a of the anode electrode 108, and a peripheral portion that does not substantially function as a plane mirror is disposed on the anode electrode 108. The reflecting mirror 103 may include a concave mirror. The reflecting mirror 103 is made of, for example, a _dielectric multilayer film reflecting mirror. The dielectric multilayer film reflecting mirror is made of, for example, _Ta2O5 / _SiO2 , SiN/ _SiO2 , or the like.

(cladding layer)
The cladding layer 105 is a p-type cladding layer, and is made of, for example, a p-GaN layer.

(Transparent conductive film)
The transparent conductive film 106 functions as a buffer layer that prevents leakage while increasing the efficiency of hole injection into the active layer 101. The transparent conductive film 106 is made of, for example, ITO, ITiO, AZO, ZnO, SnO, _SnO2 , _SnO3 , TiO, _TiO2 , graphene, or the like.

(Insulating Film)
The insulating film 107 is made of a dielectric material such as SiO ₂ , SiN, SiON, etc. The insulating film 107 has a function of preventing dielectric breakdown of the element.

(Ion implantation region)
The ion implantation region IIA is formed by implanting a high concentration of ions (e.g., B ⁺⁺ , etc.). The ion implantation region IIA has a higher resistance (lower carrier conductivity) than the non-ion implantation region surrounded by the ion implantation region IIA, and functions as a current confinement region. The non-ion implantation region surrounded by the ion implantation region IIA functions as a current passing region. The current confinement diameter (aperture diameter) by the ion implantation region IIA can be several μm (e.g., 4 μm). Here, the ion implantation region IIA is annular.

(Anode electrode)
The anode electrode 108 is made of at least one metal (including alloy) selected from the group consisting of Au, Ag, Pd, Pt, Ni, Ti, V, W, Cr, Al, Cu, Zn, Sn, and In. When the anode electrode 108 has a laminated structure, it is made of materials such as Ti/Au, Ti/Al, Ti/Al/Au, Ti/Pt/Au, Ni/Au, Ni/Au/Pt, Ni/Pt, Pd/Pt, Ag/Pd, etc. The anode electrode 108 is connected to the anode (positive electrode) of the laser driver.

(Transverse mode adjustment area)
As described above, the transverse mode adjustment region TMAA is provided in the anode electrode 108 as an example. When the region surrounding the light emitting region LA (current injection region) of the active layer 101 in a plan view is defined as the first region A1, and the region surrounded by the first region A1 is defined as the second region A2, the transverse mode adjustment region TMAA has at least one region A1 of the first and second regions A1 and A2. Here, the transverse mode adjustment region TMAA has only the first region A1 of the first and second regions A1 and A2. The first region A1 functions as a mode loss effect region that gives loss to the transverse mode. Here, the inner edge shape of the substantially annular first region A1, i.e., the shape of the opening 108a of the anode electrode 108, is substantially circular (a shape in which the circle is relatively slightly distorted in a direction perpendicular to each other). As an example, in a plan view, the area center of gravity C of the transverse mode adjustment region TMAA, i.e., the center of the first region A1, coincides with the center of the light emitting region LA (see FIG. 2), but it does not have to coincide.

FIG. 3 is a diagram for explaining the influence of the transverse mode adjustment region TMAA on each mode. As shown in FIG. 3, the transverse mode adjustment region TMAA has a low light transmittance (e.g., 0-50%) in the first region A1 and a high light transmittance (e.g., 50-100%) in the opening AP (including the case where other materials are inserted in the opening AP) of the first region A1, and adjusts the transverse mode appropriately by giving the desired loss to each mode. Specifically, the transverse mode adjustment region TMAA gives almost no mode loss to laser oscillation in a single mode (fundamental mode) transverse mode, and outputs it as is in a single mode. The transverse mode adjustment region TMAA gives a large mode loss to laser oscillation in a multimode (higher mode) transverse mode with a larger mode diameter than the single mode, and essentially converts it to a single mode and outputs it.

In the case where the transverse mode adjustment region TMAA has only the first region A1 of the first and second regions A1 and A2, when the shortest distance from the areal center C of the transverse mode adjustment region TMAA to the inner edge of the first region A1 is D _S and the longest distance is D _L , as shown in Fig. 2, in order to properly adjust the transverse mode (to a single mode having a desired transverse beam profile), it is desirable that the ratio of D S to D _L be within a predetermined range. This makes the radial loss distribution gentle, and therefore it is expected that the tolerance to manufacturing errors will be improved and the yield will also be improved.

Specifically, in the transverse mode adjusting region TMAA, it is preferable that 1≦D _L /D _S ≦10 is satisfied, it is more preferable that 1≦D _L /D _S ≦6 is satisfied, it is even more preferable that 1≦D _L /D _S ≦3 is satisfied, and it is even more preferable that 1≦D _L /D _S ≦2 is satisfied. If at least one of the above inequalities is satisfied for the ion implantation region IIA as the current confinement region, the ion implantation region IIA also formally corresponds to the transverse mode adjusting region, but since the light blocking property of the ion implantation region IIA is much lower than that of the anode electrode 108, the mode loss effect is very small, and the transverse mode adjusting function can be substantially achieved only by the anode electrode 108. That is, the transverse mode adjusting property of the transverse mode adjusting region depends on the light blocking property of the transverse mode adjusting region in addition to the satisfaction of at least one of the above inequalities. The same argument is also valid when the following combination of inequalities is satisfied for the ion implantation region IIA.

More specifically, in the transverse mode adjustment area TMAA, it is preferable that 0.5≦ _Ds /ω≦6 and 0.5≦D _L /ω≦12 hold, it is more preferable that 1≦ _Ds /ω≦6 and 1≦D _L /ω≦12 hold, it is even more preferable that 1≦ _Ds /ω≦6 and 1≦D _L /ω≦6 hold, and it is even more preferable that 1≦ _Ds /ω≦3 and 1≦D _L /ω≦6 hold.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius, ω ₀ = [λ ₀ (LR-L ² ) ^1/2 /πn] ^1/2
L _m : Vertical distance from the beam waist to the transverse mode adjustment region (effective distance)
n: refractive index of the medium _λ0 : oscillation wavelength of the surface-emitting laser L; resonator length R: radius of curvature of the concave mirror The beam waist radius _ω0 can also be defined as the distance from the center of the fundamental mode beam to the position where the radiation intensity is 1/ ^e2 (13.5%) of the maximum value.

Hereinafter, each combination of the above inequalities for D _S /ω and D _L /ω will also be referred to as a "transverse mode adjustment condition."

Here, in the transverse mode adjustment area TMAA, D _S has a larger effect on mode loss than D _L , and is important in controlling the transverse mode and further in determining the general shape of the transverse beam profile. In other words, it is more important that the value of D _S /ω is within an appropriate range.

Therefore, in the transverse mode adjustment area TMAA, it is preferable that 1≦ _Ds /ω≦3 and 1≦D _L /ω≦12 hold, it is more preferable that 1≦ _Ds /ω≦2.5 and 1≦D _L /ω≦12 hold, it is even more preferable that 1.5≦ _Ds /ω≦2.5 and 1.5≦D _L /ω≦12 hold, and it is even more preferable that 2≦ _Ds /ω≦2.5 and 2≦D _L /ω≦12 hold.

In addition, in the transverse mode adjustment area TMAA, it is also important that the value of D _L /ω is within an appropriate range in finely adjusting the beam profile in the transverse direction.

Therefore, in the transverse mode adjustment area TMAA, it is preferable that 0.5≦ _Ds /ω≦6 and 1≦D _L /ω≦6 hold, it is more preferable that 0.5≦ _Ds /ω≦4 and 1≦D _L /ω≦4 hold, it is even more preferable that 0.5≦ _Ds /ω≦3 and 1≦D _L /ω≦3 hold, and it is even more preferable that 0.5≦ _Ds /ω≦2.5 and 1≦D _L /ω≦2.5 hold.

From the above, it is more important that the values of D _S /ω and D _L /ω are within appropriate ranges in adjusting the beam profile in the transverse mode adjustment area TMAA.

Therefore, in the transverse mode adjustment area TMAA, it is preferable that 1≦D _S /ω≦3 and 1≦D _L /ω≦6 are satisfied, it is more preferable that 1≦D _S /ω≦3 and 1≦D _L /ω≦4 are satisfied, it is even more preferable that 1≦D _S /ω≦2.5 and 1≦D _L /ω≦3 are satisfied, and it is even more preferable that 1≦D _S /ω≦2.5 and 1≦D _L /ω≦2.5 are satisfied. Furthermore, 1<D _S /ω and/or 1<D _L /ω may be satisfied.

(Optical Simulation)
The anode electrode 108 having a substantially circular transverse mode adjustment area TMAA had a three-layer structure of Ti/Pt/Au, with D _S /ω being 2.2, D _L /ω being 2.25, the current confinement diameter being 4 μm, the resonator length being 24 μm, and the radius of curvature of the concave mirror 102 being 80 μm. As a result, the desired loss could be given to the transverse mode, and the transverse mode could be appropriately adjusted (to the desired single mode).

FIG. 4 is a graph showing the relationship between D _S (=D _L ) (horizontal axis: inner diameter of p-pad) and the mode loss (vertical axis: p-pad loss) in the anode electrode (p-pad) for each mode. Each line LG (Laguerre-Gaussian) in FIG. 4 shows a Gaussian distribution (where ω=2.7 μm) in a cylindrical coordinate system set in the VCSEL. The LG00 mode is the fundamental mode, and the LG10 mode, LG12 mode, LG22 mode, LG20 mode, LG01 mode, LG11 mode, LG21 mode, and LG02 mode are higher-order modes. As can be seen from FIG. 4, by setting D _S (=D _L ) to an appropriate value, it is possible to give a desired loss to each higher-order mode and adjust it to a single mode.

<Operation of surface-emitting laser>
The operation of the surface emitting laser 11 will now be described.
In the surface-emitting laser 11, when a driving voltage is applied between the anode electrode 108 and the cathode electrode 109 by the laser driver, a current flowing from the anode side of the laser driver through the anode electrode 108 is narrowed in the ion implantation region IIA through the transparent conductive film 106 and injected into the active layer 101. At this time, the active layer 101 emits light, and the light travels back and forth between the concave mirror 102 and the reflecting mirror 103 while being amplified by the active layer 101 (at this time, the light is reflected by the concave mirror 102 while being focused near the active layer 101, and is reflected by the reflecting mirror 103 as parallel light or weakly diffused light toward the active layer 101), and is emitted as a laser light from the reflecting mirror 103 when the oscillation condition is satisfied. At this time, a desired loss is given to the transverse mode by the transverse mode adjustment region TMAA, and a single-mode laser light having a desired transverse beam profile is output. The current injected into the active layer 101 flows through the substrate 104 and out of the cathode electrode 109 to the cathode side of the laser driver.

<Manufacturing method of surface-emitting laser>
A method for manufacturing the surface-emitting laser 11 will be described below with reference to the flow chart of Fig. 5. As an example, a plurality of surface-emitting lasers 11 are simultaneously produced on a single wafer (e.g., an n-GaN substrate, hereinafter referred to as "substrate 104" for convenience) that serves as the base material for the substrate 104. Next, the series of surface-emitting lasers 11 are separated from one another to obtain chip-shaped surface-emitting lasers 11 (surface-emitting laser chips).

In the first step S1, the active layer 101 and the cladding layer 105 are laminated on the substrate 104 (see FIG. 6A). Specifically, the active layer 101 and the cladding layer 105 are laminated in this order on the substrate 104 in a growth chamber by metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE) to generate a laminate.

In the next step S2, the electrode installation portion 104b is formed (see FIG. 6B). Specifically, a resist pattern is formed on the laminate to cover areas other than the areas where the electrode installation portion 104b is to be formed, and the laminate is etched using the resist pattern as a mask. At this time, etching is continued until the substrate 104 is exposed. As a result, a cutout-shaped electrode installation portion 104b is formed in the laminate.

In the next step S3, an ion implantation region IIA is formed (see FIG. 7A). Specifically, a protective film made of resist, _SiO2 , or the like is formed to cover the portion of the laminate other than the portion where the ion implantation region IIA is to be formed, and ions (e.g., B ⁺⁺ ) are implanted into the laminate from the cladding layer 105 side using the protective film as a mask. At this time, the ion implantation depth is set to reach inside the substrate 104.

In the next step S4, the insulating film 107 is formed (see FIG. 7B). Specifically, first, the insulating film 107 is formed over the entire surface of the laminate by, for example, vacuum deposition, sputtering, or the like. Next, the insulating film 107 other than the insulating film 107 covering the peripheral portion of the cladding layer 105 is removed by photolithography and etching. As a result, a ring-shaped insulating film 107 is formed that covers the peripheral portion of the cladding layer 105.

In the next step S5, the transparent conductive film 106 is formed (see FIG. 8A). Specifically, first, the transparent conductive film 106 is formed over the entire surface of the laminate by, for example, vacuum deposition, sputtering, or the like. Next, the transparent conductive film 106 other than the transparent conductive film 106 covering the center of the first cladding layer 105 and the inner periphery of the insulating film 107 is removed by photolithography and etching. As a result, the transparent conductive film 106 covering the center of the first cladding layer 105 and the inner periphery of the insulating film 107 is formed.

In the next step S6, the anode electrode 108 and the cathode electrode 109 are formed (see FIG. 8B). Specifically, for example, using a lift-off method, the ring-shaped anode electrode 108 is formed to cover the peripheral portion including the outer periphery of the transparent conductive film 106 and the outer periphery of the insulating film 107, and the cathode electrode 109 is formed on the electrode installation portion 104b. At this time, the electrode material is deposited by, for example, a vacuum deposition method, sputtering, etc.

In the next step S7, the reflector 103 is formed (see FIG. 9A). Specifically, first, a dielectric multilayer film, which is the material of the reflector 103, is formed on the entire surface of the laminate by, for example, vacuum deposition, sputtering, or CVD. Next, the dielectric multilayer film other than the dielectric multilayer film that covers the transparent conductive film 106 and the anode electrode 108 is removed by photolithography and etching. As a result, the reflector 103 is formed, which is a dielectric multilayer film reflector that covers the transparent conductive film 106 and the anode electrode 108.

In the next step S8, the convex structure 104a is formed (see FIG. 9B). Specifically, first, a fluid material is patterned on the back surface (lower surface) of the substrate 104. More specifically, first, a fluid material (e.g., photoresist) is formed by photolithography at the location on the back surface of the substrate 104 where the convex structure 104a will be formed. Next, the fluid material is formed into a convex shape by reflow. Specifically, the fluid material is molded into a convex shape (e.g., an approximately hemispherical shape) by reflow at a temperature of 200°C. Etching is performed using the fluid material as a mask to form the convex structure 104a. Specifically, the substrate 104 is dry-etched by photolithography using the fluid material as a mask to form the convex structure 104a (e.g., an approximately hemispherical structure).

In the final step S9, the concave mirror 102 is formed (see FIG. 10). Specifically, the material of the concave mirror 102 (e.g., a dielectric multilayer film) is deposited on the convex structure 104a by, for example, vacuum deposition, sputtering, or CVD. As a result, the concave mirror 102 is formed in a shape that matches the convex structure 104a. This produces a plurality of surface-emitting lasers 11 on a wafer (semiconductor substrate (e.g., n-GaN substrate)). After that, the series of surface-emitting lasers 11 are separated by dicing to obtain chip-shaped surface-emitting lasers 11 (surface-emitting laser chips). The surface-emitting lasers 11 are then mounted in, for example, a CAN package. More specifically, the surface of the surface-emitting laser 11 on the concave mirror 102 side is soldered to the CAN package.

<Effects of surface-emitting lasers>
Hereinafter, effects of the surface emitting laser 11 according to the example 1 of the embodiment of the present technology will be described.

The surface-emitting laser 11 includes an active layer 101, a first structure ST1 having a concave mirror 102 arranged on one side of the active layer 101, and a second structure ST2 having a reflecting mirror 103 arranged on the other side of the active layer 101. A transverse mode adjustment region TMAA is provided in the second structure ST2, and when a region surrounding the light emitting region LA of the active layer 101 in a plan view is defined as a first region A1 and a region surrounded by the first region A1 is defined as a second region A2, the transverse mode adjustment region TMAA has at least the first region A1 of the first and second regions A1 and A2. When the transverse mode adjustment region TMAA has only the first region A1 of the first and second regions A1 and A2, and the shortest distance from the areal center of gravity of the transverse mode adjustment region TMAA to the inner edge of the first region A1 is defined as D _S and the longest distance is defined as D _L , 1≦D _L /D _S ≦10 is satisfied.

The surface-emitting laser 11 can provide a surface-emitting laser that can impart a desired loss to the transverse mode. By imparting a desired loss to the transverse mode, a single transverse mode output of only the fundamental mode becomes possible.

Furthermore, the surface-emitting laser 11 has a gentle radial loss distribution, improving tolerance to manufacturing errors and improving yields.

The outer peripheral length of the transverse mode adjustment area TMAA included in the anode electrode 108 can be made relatively long, making the lift-off process easier and improving yields.

The anode electrode 108, including the transverse mode adjustment area TMAA, is made of metal, which contributes more to mode loss than semiconductors or dielectrics, and provides high mode controllability.

By using a metal with higher thermal conductivity as the material for the anode electrode 108, including the transverse mode adjustment area TMAA, it is possible to make it function as a heat sink and improve heat dissipation.

The transverse mode adjustment region TMAA can also be used for wavelength control and polarization control by using surface plasmons that may exist on the metal surface. In particular, since D _S <D _L is satisfied, the surface area of the metal surface is larger than that of a circular aperture, and therefore stronger surface plasmons can be expected.

Since the transverse mode adjustment region TMAA is included in the anode electrode 108, the transverse mode adjustment region TMAA can be formed by the same process as in the conventional method.

Because the transverse mode adjustment area TMAA is included in the anode electrode 108, the inner diameter of the anode electrode 108 can be reduced (the surface area can be increased) to reduce the internal resistance, thereby improving the IV characteristics (current-voltage characteristics).

2. Surface-emitting laser according to Example 2 of an embodiment of the present technology
Hereinafter, a surface emitting laser according to a second example of an embodiment of the present technology will be described with reference to the drawings.

Fig. 11A is a plan view of the transverse mode adjustment area TMAA of a surface-emitting laser 12 according to Example 2 of an embodiment of the present technology. Fig. 11B is a graph showing the relationship between the radial position of light and the mode loss when the inner edge shape of the transverse mode adjustment area TMAA is substantially circular and polygonal.

As shown in FIG. 11A, the surface-emitting laser 12 has a configuration similar to that of the surface-emitting laser 11 according to the first embodiment, except that the inner edge shape of the transverse mode adjustment area TMAA (the shape of the opening 108a of the anode electrode 108) is a regular pentagon.

As shown in FIG. 11B, the surface-emitting laser 12 has a more gentle radial loss distribution than the surface-emitting laser 11, in which the inner edge of the transverse mode adjustment area TMAA has a substantially circular shape.

The surface-emitting laser 12 achieves the same effects as the surface-emitting laser 11 of Example 1, while also improving tolerance to manufacturing errors and yield.

(Optical Simulation)
The anode electrode 108 having a substantially regular pentagonal transverse mode adjustment region TMAA had a three-layer structure of Ti/Pt/Au, with D _S /ω being 2.2, D _L /ω being 2.7, the current confinement diameter being 4 μm, the resonator length being 24 μm, and the curvature radius of the concave mirror 102 being 80 μm. As a result, the desired loss could be given to the transverse mode, and the transverse mode could be appropriately adjusted (to the desired single mode).

<3. Surface-emitting laser according to Example 3 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to a third example of an embodiment of the present technology will be described with reference to the drawings.

Fig. 12A is a plan view of the transverse mode adjustment area TMAA of a surface-emitting laser 13 according to Example 3 of an embodiment of the present technology. Fig. 12B is a graph showing the relationship between the radial position of light and the mode loss when the inner edge shape of the transverse mode adjustment area TMAA is substantially circular and star-shaped.

As shown in FIG. 12A, the surface-emitting laser 13 has a configuration similar to that of the surface-emitting laser 11 according to the first embodiment, except that the inner edge shape of the transverse mode adjustment area TMAA (the shape of the opening 108a of the anode electrode 108) is star-shaped.

As shown in FIG. 12B, the surface-emitting laser 13 has a more gentle radial loss distribution than the surface-emitting laser 11, in which the inner edge of the transverse mode adjustment area TMAA has a substantially circular shape.

The surface-emitting laser 13 provides the same effects as the surface-emitting laser 11 of Example 1, and also provides improved tolerance to manufacturing errors and improved yield.

The shape of the inner edge of the transverse mode adjustment region TMAA of the surface-emitting laser 13 is not limited to a star shape, but may be any shape that satisfies the following formula (1) (for example, a shape in which the inner edge of the first region A1 has multiple convex portions that protrude radially toward the outer edge side of the first region A1).

where ρ is the radius, φ is the angle, n is the number of vertices of the convex shape, m is a value that determines how many vertices the sides will pass through to line up on a straight line, and k is the rigidity. Supplementally, in the above formula (1), when k=0, it represents a circle regardless of other parameters, when k=1, it represents a polygon including straight lines, and when it is an intermediate value between 0<k<1, it represents a figure intermediate between a circle and a polygon. For example, when n=7, k=0.3, and m=3, the above formula (1) represents a polygon similar to a star shape.

(Optical Simulation)
The anode electrode 108 having a star-shaped transverse mode adjustment region TMAA had a three-layer structure of Ti/Pt/Au, with D _S /ω being 2.2, D _L /ω being 2.3, the current confinement diameter being 4 μm, the resonator length being 24 μm, and the curvature radius of the concave mirror 102 being 80 μm. As a result, the desired loss could be given to the transverse mode, and the transverse mode could be appropriately adjusted (to the desired single mode).

<4. Surface-emitting laser according to Example 4 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to a fourth embodiment of the present technology will be described with reference to the drawings.

Fig. 13A is a plan view of the transverse mode adjustment area TMAA of a surface-emitting laser 14 according to Example 4 of an embodiment of the present technology. Fig. 13B is a graph showing the relationship between the radial position of light and the mode loss when the inner edge shape of the transverse mode adjustment area TMAA is substantially circular and when it is rose-shaped.

As shown in FIG. 13A, the surface-emitting laser 14 has a configuration similar to that of the surface-emitting laser 11 according to the first embodiment, except that the inner edge shape of the transverse mode adjustment area TMAA (the shape of the opening 108a of the anode electrode 108) is rose-shaped.

As shown in FIG. 13B, the surface-emitting laser 14 has a more gentle radial loss distribution than the surface-emitting laser 11, in which the inner edge of the transverse mode adjustment area TMAA has a substantially circular shape.

The surface-emitting laser 14 achieves the same effects as the surface-emitting laser 11 of Example 1, and also improves tolerance to manufacturing errors and yields.

The shape of the inner edge of the transverse mode adjustment region TMAA of the surface-emitting laser 13 is not limited to a rose shape, but may be any shape that satisfies the following formula (2) (for example, a shape in which the inner edge of the first region A1 has multiple convex portions that protrude radially toward the outer edge side of the first region A1).

where r is the radius, θ is the angle, n is the number of vertices of the convex shape, and d is a variable that gives variation in shape. Additionally, the shape of the figure expressed by formula (2) changes depending on the value of d.

The anode electrode 108 having a rose-shaped transverse mode adjustment region TMAA had a three-layer structure of Ti/Pt/Au, with D _S /ω being 2.2, D _L /ω being 2.3, the current confinement diameter being 4 μm, the resonator length being 24 μm, and the curvature radius of the concave mirror 102 being 80 μm. As a result, the desired loss could be given to the transverse mode, and the transverse mode could be appropriately adjusted (to the desired single mode).

<5. Surface-emitting laser according to Example 5 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to a fifth embodiment of the present technology will be described with reference to the drawings.

FIG. 14 is a plan view of the transverse mode adjustment area TMAA of a surface-emitting laser 15 according to Example 5 of an embodiment of the present technology.

As shown in FIG. 14, the surface-emitting laser 15 has a similar configuration to the surface-emitting laser 11 of Example 1, except that the inner edge shape of the transverse mode adjustment area TMAA (the shape of the opening 108a of the anode electrode 108) is elliptical (a shape formed by relatively distorting a circle in mutually orthogonal directions).

The surface-emitting laser 15 provides the same effects as the surface-emitting laser 11 of Example 1 and can also perform polarization control.

(Optical Simulation)
The anode electrode 108 having an elliptical transverse mode adjustment region TMAA has a three-layer structure of Ti/Pt/Au, with D _S /ω being 2.1, D _L /ω being 2.4, the current confinement diameter being 4 μm, the resonator length being 24 μm, and the radius of curvature of the concave mirror 102 being 80 μm. As a result, it was possible to give the desired loss to the transverse mode and perform polarization control, and it was possible to properly adjust the transverse mode (to the desired single mode) and align the polarization direction.

<6. Surface-emitting laser according to Example 6 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 6 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 15 is a plan view of the transverse mode adjustment area TMAA of a surface-emitting laser 16 according to Example 6 of an embodiment of the present technology.

As shown in FIG. 15, the surface-emitting laser 16 has a configuration generally similar to that of the surface-emitting laser 11 of Example 1, except that the transverse mode adjustment area TMAA has first and second areas A1 and A2. As described above, the second area A2 is an area surrounded by the first area A1.

The first and second regions A1 and A2 function as mode loss effect regions that give loss to the transverse mode. Here, the second region A2 is composed of multiple (e.g., three) circular portions separated from each other and arranged inside the annular first region A1, i.e., within the opening A1a of the first region A1. As an example, the multiple portions constituting the second region A2 are arranged two-dimensionally at a predetermined pitch in a planar view. In detail, the three portions constituting the second region A2 are located on the three vertices of an equilateral triangle centered on the center of the first region A1. In a planar view, the equilateral triangle surrounds the light-emitting region LA. Note that each of the multiple (e.g., three) portions of the second region A2 may have a shape other than a circle, such as an ellipse or polygon. Here, the center of the equilateral triangle coincides with the center of the first region A1, but it does not have to coincide. The triangle with each portion of the second region A2 as a vertex is not limited to an equilateral triangle, and may be another triangle such as an isosceles triangle. In other words, the multiple portions constituting the second region A2 may not have a constant arrangement pitch in a planar view.

In the case where the transverse mode adjustment region TMAA has the first and second regions A1 and A2, when the shortest distance from the center of gravity of the transverse mode adjustment region TMAA to the inner edge of the first region A1 and the outer edge of the second region A2 is D _S and the longest distance is D _L , it is desirable that the ratio of D S to D _L be within a predetermined range in order to properly adjust the transverse mode (to a single mode having a desired transverse beam profile), as shown in Fig. 15. This makes the radial loss distribution gentle, and therefore it is expected that the tolerance to manufacturing errors will be improved and the yield will also be improved.

Specifically, in the transverse mode adjustment area TMAA, it is preferable that 1≦D _L /D _S ≦10 holds, it is more preferable that 1≦D _L /D _S ≦6 holds, it is even more preferable that 1≦D _L /D _S ≦3 holds, and it is even more preferable that 1≦D _L /D _S ≦2 holds.

More specifically, in the transverse mode adjustment area TMAA, it is preferable that 0.5≦ _Ds /ω≦6 and 0.5≦D _L /ω≦12 hold, it is more preferable that 1≦ _Ds /ω≦6 and 1≦D _L /ω≦12 hold, it is even more preferable that 1≦ _Ds /ω≦6 and 1≦D _L /ω≦6 hold, and it is even more preferable that 1≦ _Ds /ω≦3 and 1≦D _L /ω≦6 hold.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius, ω ₀ = [λ ₀ (LR-L ² ) ^1/2 /πn] ^1/2
L _m : Vertical distance from the beam waist to the transverse mode adjustment region (effective distance)
n: refractive index of the medium λ ₀ : oscillation wavelength of the surface emitting laser L; resonator length R: radius of curvature of the concave mirror

In addition, in the transverse mode adjustment area TMAA, D _S has a larger effect on the mode loss than D _L , and is important in determining the general shape of the transverse beam profile. In other words, it is more important that the value of D _S /ω is within an appropriate range.

Therefore, in the transverse mode adjustment area TMAA, it is preferable that 1≦ _Ds /ω≦3 and 1≦D _L /ω≦12 hold, it is more preferable that 1≦ _Ds /ω≦2.5 and 1≦D _L /ω≦12 hold, it is even more preferable that 1.5≦ _Ds /ω≦2.5 and 1.5≦D _L /ω≦12 hold, and it is even more preferable that 2≦ _Ds /ω≦2.5 and 2≦D _L /ω≦12 hold.

In addition, in the transverse mode adjustment area TMAA, it is also important that the value of D _L /ω is within an appropriate range in finely adjusting the beam profile in the transverse direction.

Therefore, in the transverse mode adjustment area TMAA, it is preferable that 0.5≦ _Ds /ω≦6 and 1≦D _L /ω≦6 hold, it is more preferable that 0.5≦ _Ds /ω≦4 and 1≦D _L /ω≦4 hold, it is even more preferable that 0.5≦ _Ds /ω≦3 and 1≦D _L /ω≦3 hold, and it is even more preferable that 0.5≦ _Ds /ω≦2.5 and 1≦D _L /ω≦2.5 hold.

From the above, it is more important that the values of D _S /ω and D _L /ω are within appropriate ranges in adjusting the beam profile in the transverse mode adjustment area TMAA.

Therefore, in the transverse mode adjustment area TMAA, it is preferable that 1≦D _S /ω≦3 and 1≦D _L /ω≦6 are satisfied, it is more preferable that 1≦D _S /ω≦3 and 1≦D _L /ω≦4 are satisfied, it is even more preferable that 1≦D _S /ω≦2.5 and 1≦D _L /ω≦3 are satisfied, and it is even more preferable that 1≦D _S /ω≦2.5 and 1≦D _L /ω≦2.5 are satisfied. Furthermore, 1<D _S /ω and/or 1<D _L /ω may be satisfied.

The surface-emitting laser 16 has the same effect as the surface-emitting laser 11 of Example 1, and since the transverse mode adjustment area TMAA has the first and second areas A1 and A2, mode control is possible without affecting the IV characteristics, and since it can be designed according to the mode shape to be suppressed, more accurate mode control is possible. In contrast, if a method is used to simply narrow the inner diameter of the anode electrode (ring electrode), for example, the current path will change due to the anode electrode, which may affect the IV characteristics.

(Optical Simulation)
The anode electrode 108 including the transverse mode adjustment region TMAA having the first and second regions A1 and A2 had a three-layer structure of Ti/Pt/Au, with D _S /ω being 2.1, D _L /ω being 2.4, the current confinement diameter being 4 μm, the resonator length being 24 μm, and the radius of curvature of the concave mirror 102 being 80 μm. As a result, it was possible to impart a desired loss to the transverse mode, and to properly adjust the transverse mode (to a desired single mode).

7. Surface-emitting laser according to Example 7 of an embodiment of the present technology
Hereinafter, a surface emitting laser according to Example 7 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 16 is a plan view of the transverse mode adjustment area TMAA of a surface-emitting laser 17 according to Example 7 of an embodiment of the present technology.

As shown in FIG. 16, the surface-emitting laser 17 has a configuration generally similar to that of the surface-emitting laser 11 of Example 1, except that the transverse mode adjustment area TMAA has first and second areas A1 and A2. As described above, the second area A2 is an area surrounded by the first area A1.

The first and second regions A1 and A2 function as mode loss effect regions that give loss to the transverse mode. Here, the annular second region A2 (region approximately similar to the first region A1) is arranged inside the annular first region A1, i.e., within the opening A1a of the first region A1. As an example, the first and second regions A1 and A2 are arranged concentrically. The second region A2 surrounds the light emitting region LA in a planar view. That is, the light emitting region LA is located within the opening A2a of the second region A2 in a planar view. Note that the first and second regions A1 and A2 do not have to be arranged concentrically. Here, the area center of gravity C of the transverse mode adjustment region TMAA coincides with the center of the light emitting region LA in a planar view, but it does not have to coincide. Here, the second region A2 consists of a single annular region, but may have multiple concentric or heterocentric annular regions (regions approximately similar).

In the case where the transverse mode adjustment region TMAA has the first and second regions A1 and A2, when the shortest distance from the areal center C of the transverse mode adjustment region TMAA to the inner edge of the first region A1 and the outer edge of the second region A2 is D _S and the longest distance is D _L , it is desired that the ratio of D S to D _L be within a predetermined range in order to properly adjust the transverse mode (to a single mode having a desired transverse beam profile), as shown in Fig. 16. This makes the radial loss distribution gentle, and therefore it is expected that the tolerance to manufacturing errors will be improved and the yield will also be improved.

Specifically, in the transverse mode adjustment area TMAA, it is preferable that 1≦D _L /D _S ≦10 holds, it is more preferable that 1≦D _L /D _S ≦6 holds, it is even more preferable that 1≦D _L /D _S ≦3 holds, and it is even more preferable that 1≦D _L /D _S ≦2 holds.

More specifically, in the transverse mode adjustment area TMAA, it is preferable that 0.5≦ _Ds /ω≦6 and 0.5≦D _L /ω≦12 hold, it is more preferable that 1≦ _Ds /ω≦6 and 1≦D _L /ω≦12 hold, it is even more preferable that 1≦ _Ds /ω≦6 and 1≦D _L /ω≦6 hold, and it is even more preferable that 1≦ _Ds /ω≦3 and 1≦D _L /ω≦6 hold.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius, ω ₀ = [λ ₀ (LR-L ² ) ^1/2 /πn] ^1/2
L _m : Vertical distance from the beam waist to the transverse mode adjustment region (effective distance)
n: refractive index of the medium λ ₀ : oscillation wavelength of the surface emitting laser L; resonator length R: radius of curvature of the concave mirror

In addition, in the transverse mode adjustment area TMAA, D _S has a larger effect on the mode loss than D _L , and is important in determining the general shape of the transverse beam profile. In other words, it is more important that the value of D _S /ω is within an appropriate range.

Therefore, in the transverse mode adjustment area TMAA, it is preferable that 1≦ _Ds /ω≦3 and 1≦D _L /ω≦12 hold, it is more preferable that 1≦ _Ds /ω≦2.5 and 1≦D _L /ω≦12 hold, it is even more preferable that 1.5≦ _Ds /ω≦2.5 and 1.5≦D _L /ω≦12 hold, and it is even more preferable that 2≦ _Ds /ω≦2.5 and 2≦D _L /ω≦12 hold.

From the above, it is more important that the values of D _S /ω and D _L /ω are within appropriate ranges in adjusting the beam profile in the transverse mode adjustment area TMAA.

Therefore, in the transverse mode adjustment area TMAA, it is preferable that 1≦D _S /ω≦3 and 1≦D _L /ω≦6 are satisfied, it is more preferable that 1≦D _S /ω≦3 and 1≦D _L /ω≦4 are satisfied, it is even more preferable that 1≦D _S /ω≦2.5 and 1≦D _L /ω≦3 are satisfied, and it is even more preferable that 1≦D _S /ω≦2.5 and 1≦D _L /ω≦2.5 are satisfied. Furthermore, 1<D _S /ω and/or 1<D _L /ω may be satisfied.

In addition, in the transverse mode adjustment area TMAA, it is also important that the value of D _L /ω is within an appropriate range in finely adjusting the beam profile in the transverse direction.

Therefore, in the transverse mode adjustment area TMAA, it is preferable that 0.5≦ _Ds /ω≦6 and 1≦D _L /ω≦6 hold, it is more preferable that 0.5≦ _Ds /ω≦4 and 1≦D _L /ω≦4 hold, it is even more preferable that 0.5≦ _Ds /ω≦3 and 1≦D _L /ω≦3 hold, and it is even more preferable that 0.5≦ _Ds /ω≦2.5 and 1≦D _L /ω≦2.5 hold.

The surface-emitting laser 17 has the same effect as the surface-emitting laser 11 of Example 1, and since the transverse mode adjustment area TMAA has the first and second areas A1 and A2, mode control is possible without affecting the IV characteristics, and since it can be designed according to the mode shape to be suppressed, more precise mode control is possible.

(Optical Simulation)
The anode electrode 108 including the transverse mode adjustment region TMAA having the first and second regions A1 and A2 had a three-layer structure of Ti/Pt/Au, with D _S /ω being 2.1, D _L /ω being 2.4, the current confinement diameter being 4 μm, the resonator length being 24 μm, and the radius of curvature of the concave mirror 102 being 80 μm. As a result, it was possible to impart a desired loss to the transverse mode, and to properly adjust the transverse mode (to a desired single mode).

8. Surface-emitting laser according to Example 8 of an embodiment of the present technology
<Configuration of surface-emitting laser>
Hereinafter, a surface emitting laser according to an eighth embodiment of the present technology will be described with reference to the drawings.

FIG. 17 is a cross-sectional view of a surface-emitting laser 18 according to Example 8 of an embodiment of the present technology.

The surface-emitting laser 18 has a configuration generally similar to that of the surface-emitting laser 11 according to the first embodiment, except that the cathode electrode 109 is disposed on one side (lower side) of the active layer 101, and the cathode electrode 109 has a transverse mode adjustment region TMAA. The surface-emitting laser 18 does not have an electrode installation portion 104b. In the surface-emitting laser 18, the above-mentioned transverse mode adjustment condition is not satisfied for the anode electrode 108, and the anode electrode 108 does not function as the transverse mode adjustment region TMAA.

In the surface-emitting laser 18, a concave mirror 102 (hereinafter also referred to as the "concave mirror central portion") is provided in the center of the convex structure 104a of the substrate 104, and a cathode electrode 109 (hereinafter also referred to as the "concave mirror peripheral portion") is provided across the peripheral portion of the convex structure 104a and the flat portion around the peripheral portion. Here, the cathode electrode 109, which is the peripheral portion of the concave mirror, has a transverse mode adjustment area TMAA. In other words, the cathode electrode 109 satisfies at least one of the transverse mode adjustment conditions described above.

<Manufacturing method of surface-emitting laser>
A method for manufacturing the surface-emitting laser 18 will be described below with reference to the flow chart of Fig. 18. Here, as an example, a plurality of surface-emitting lasers 18 are simultaneously produced on a single wafer (e.g., an n-GaN substrate, hereinafter referred to as "substrate 104" for convenience) that serves as the base material for the substrate 104. Next, the series of surface-emitting lasers 18 are separated from one another to obtain chip-shaped surface-emitting lasers 18 (surface-emitting laser chips).

In the first step S11, the active layer 101 and the cladding layer 105 are laminated on the substrate 104 (see FIG. 19A). Specifically, the active layer 101 and the cladding layer 105 are laminated in this order on the substrate 104 in a growth chamber by metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE) to generate a laminate.

In the next step S12, an ion implantation region IIA is formed (see FIG. 19B). Specifically, a protective film made of resist, _SiO2 , or the like is formed to cover the portion of the laminate other than the portion where the ion implantation region IIA is to be formed, and ions (e.g., B ⁺⁺ ) are implanted into the laminate from the cladding layer 105 side using the protective film as a mask. At this time, the ion implantation depth is set to reach inside the substrate 104.

In the next step S13, the insulating film 107 is formed (see FIG. 20A). Specifically, first, the insulating film 107 is formed over the entire surface of the laminate by, for example, vacuum deposition, sputtering, or the like. Next, the insulating film 107 other than the insulating film 107 covering the peripheral portion of the cladding layer 105 is removed by photolithography and etching. As a result, a ring-shaped insulating film 107 is formed that covers the peripheral portion of the cladding layer 105.

In the next step S14, the transparent conductive film 106 is formed (see FIG. 20B). Specifically, first, the transparent conductive film 106 is formed over the entire surface of the laminate by, for example, vacuum deposition, sputtering, or the like. Next, the transparent conductive film 106 other than the transparent conductive film 106 covering the center of the first cladding layer 105 and the inner periphery of the insulating film 107 is removed by photolithography and etching. As a result, the transparent conductive film 106 covering the center of the first cladding layer 105 and the inner periphery of the insulating film 107 is formed.

In the next step S15, the anode electrode 108 is formed (see FIG. 21A). Specifically, for example, a lift-off method is used to form the ring-shaped anode electrode 108 that covers the outer periphery of the transparent conductive film 106 and the outer periphery of the insulating film 107. The electrode material is deposited by, for example, vacuum deposition, sputtering, etc.

In the next step S16, the reflector 103 is formed (see FIG. 21B). Specifically, a dielectric multilayer film, which is the material of the reflector 103, is formed on the entire surface of the laminate by, for example, vacuum deposition, sputtering, or CVD. As a result, the reflector 103 is formed, which is a dielectric multilayer film reflector that covers the transparent conductive film 106 and the anode electrode 108.

In the next step S17, the convex structure 104a is formed (see FIG. 22A). Specifically, first, a fluid material is patterned on the back surface (lower surface) of the substrate 104. More specifically, first, a fluid material (e.g., photoresist) is formed by photolithography at the location on the back surface of the substrate 104 where the convex structure 104a will be formed. Next, the fluid material is formed into a convex shape by reflow. Specifically, the fluid material is molded into a convex shape (e.g., an approximately hemispherical shape) by reflow at a temperature of 200°C. Etching is performed using the fluid material as a mask to form the convex structure 104a. Specifically, the substrate 104 is dry-etched by photolithography using the fluid material as a mask to form the convex structure 104a (e.g., an approximately hemispherical structure).

In the next step S18, the cathode electrode 109 is formed (see FIG. 22B). Specifically, the cathode electrode 109 is formed so as to cover the peripheral portion of the convex structure 104a and the flat portion around the peripheral portion, for example, using a lift-off method. The electrode material is deposited by, for example, vacuum deposition, sputtering, etc.

In the final step S19, the concave mirror 102 is formed (see FIG. 23). Specifically, first, the material of the concave mirror 102 (e.g., a dielectric multilayer film) is formed by, for example, vacuum deposition, sputtering, or CVD so as to cover the cathode electrode 109 and the center of the convex structure 104a. Next, the dielectric multilayer film other than the dielectric multilayer film covering the center of the convex structure 104a is removed by photolithography and etching. As a result, the concave mirror 102 is formed in a shape that imitates the center of the convex structure 104a. This produces a plurality of surface-emitting lasers 18 on a wafer (semiconductor substrate (e.g., n-GaN substrate)). After that, the series of surface-emitting lasers 18 are separated by dicing to obtain chip-shaped surface-emitting lasers 18 (surface-emitting laser chips). The surface-emitting lasers 18 are then mounted, for example, in a CAN package. More specifically, the surface of the surface-emitting laser 18 on the concave mirror side is soldered to the CAN package.

<Effects of surface-emitting lasers>
According to the surface-emitting laser 18, the same effects as those of the surface-emitting laser 11 of Example 1 are achieved, and since the cathode electrode 109 having the transverse mode adjustment area TMAA is provided at the position of the concave mirror 102 where the beam diameter is maximum, the tolerance to manufacturing errors is improved, and the yield is improved.

(Optical Simulation)
The cathode electrode 109 having the transverse mode adjustment region TMAA has a three-layer structure of Ti/Pt/Au, D _S /ω is 2.2, D _L /ω is 2.25, the current confinement diameter is 4 μm, the resonator length is 24 μm, and the curvature radius of the concave mirror 102 is 80 μm. As a result, the desired loss can be given to the transverse mode, and the transverse mode can be appropriately (
It was possible to adjust the output to the desired single mode.

<9. Surface-emitting laser according to Example 9 of an embodiment of the present technology>
<Configuration of surface-emitting laser>
Hereinafter, a surface emitting laser according to a ninth example of an embodiment of the present technology will be described with reference to the drawings.

FIG. 24 is a cross-sectional view of a surface-emitting laser 19 according to Example 9 of an embodiment of the present technology.

The surface-emitting laser 19 has a configuration generally similar to that of the surface-emitting laser 11 according to the first embodiment, except that the ion implantation region IIA serving as a current confinement region has a transverse mode adjustment region TMAA. Here, the anode electrode 108 does not satisfy the transverse mode adjustment conditions described above, and does not have a transverse mode adjustment function.

In the surface-emitting laser 19, the transverse mode adjustment region TMAA of the ion implantation region IIA is, for example, approximately annular, and satisfies at least one of the transverse mode adjustment conditions described above.

The shape of the ion implantation region IIA of the surface-emitting laser 19 may be the same as the shape of the transverse mode adjustment region TMAA of the surface-emitting lasers 12 to 17 according to Examples 2 to 7, and at least one of the transverse mode adjustment conditions may be satisfied.

In the surface-emitting laser 19, the ion implantation region IIA has the transverse mode adjustment region TMAA, so that the transverse mode adjustment region TMAA can be fabricated by the same process as in the conventional method.

(Optical Simulation)
The ion species of the ion implantation region IIA having the transverse mode adjustment region TMAA was B+, D _S /ω was 2.2, D _L /ω was 2.25, the current confinement diameter was 4 μm, the resonator length was 24 μm, and the radius of curvature of the concave mirror 102 was 80 μm. As a result, the desired loss could be given to the transverse mode, and the transverse mode could be appropriately adjusted (to the desired single mode).

<10. Surface-emitting laser according to Example 10 of an embodiment of the present technology>
<Configuration of surface-emitting laser>
Hereinafter, a surface emitting laser according to a tenth example of an embodiment of the present technology will be described with reference to the drawings.

FIG. 25 is a cross-sectional view of a surface-emitting laser 20 according to Example 10 of an embodiment of the present technology.

As shown in FIG. 25, the surface-emitting laser 20 has a configuration generally similar to that of the surface-emitting laser 11 of Example 1, except that the transverse mode adjustment area TMAA has a plurality of protrusions 104a1 (microstructures) provided on the convex structure 104a of the substrate 104.

In the surface-emitting laser 20, the transverse mode adjustment area TMAA is an annular protrusion formation area in which multiple protrusions 104a1 are formed along the circumferential direction on the peripheral portion of the convex structure 104a, which corresponds to the peripheral portion of the concave mirror 102. At least one of the transverse mode adjustment conditions described above is satisfied for this protrusion formation area. This protrusion formation area functions as a mode loss effect area.

<Manufacturing method of surface-emitting laser>
The surface emitting laser 20 is manufactured, for example, according to the procedure of the flow chart shown in Fig. 26. Steps S21 to S27 in Fig. 26 are similar to steps S1 to S7 in Fig. 5, respectively.

In step S28, a protruding convex structure is formed, which is a convex structure 104a having a plurality of protrusions 104a1 (see FIG. 27A). The protruding convex structure is formed by, for example, performing photolithography and etching on the convex structure 104a (see FIG. 9B).

In the final step S29, the concave mirror 102 is formed (see FIG. 27B). Specifically, the material of the concave mirror 102 (e.g., a dielectric multilayer film) is deposited on the protruding convex structure by, for example, vacuum deposition, sputtering, or CVD. As a result, the concave mirror 102 is formed in a shape that matches the protruding convex structure. This produces a plurality of surface-emitting lasers 20 on a wafer (semiconductor substrate (e.g., n-GaN substrate)). After that, the series of surface-emitting lasers 20 is separated by dicing to obtain chip-shaped surface-emitting lasers 20 (surface-emitting laser chips). The surface-emitting lasers 20 are then mounted in, for example, a CAN package. More specifically, the surface of the surface-emitting laser 20 on the concave mirror 102 side is soldered to the CAN package.

<Effects of surface-emitting lasers>
The surface-emitting laser 20 exhibits the same effects as the surface-emitting laser 11 of the first embodiment, and since the transverse mode adjustment region TMAA is provided at the position of the concave mirror 102 where the beam diameter is maximum, the tolerance to manufacturing errors is improved and the yield is improved, and since the transverse mode adjustment region TMAA has a plurality of protrusions 104a1, the adhesion with solder is improved.

(Optical Simulation)
When the transverse mode adjustment region TMAA has multiple protrusions 104a1, D _S /ω is 2.2, D _L /ω is 2.2, the current confinement diameter is 4 μm, the resonator length is 24 μm, and the curvature radius of the concave mirror 102 is 80 μm. As a result, it is possible to impart a desired loss to the transverse mode, and to properly adjust the transverse mode (to a desired single mode).

<11. Surface-emitting laser according to Example 11 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to an eleventh example of an embodiment of the present technology will be described with reference to the drawings.

FIG. 28 is a cross-sectional view of a surface-emitting laser 21 according to Example 11 of an embodiment of the present technology.

As shown in FIG. 28, the surface-emitting laser 21 has a configuration generally similar to that of the surface-emitting laser 11 of Example 1, except that the insulating film 107 has a transverse mode adjustment region TMAA.

In the surface-emitting laser 21, the annular insulating film 107 satisfies at least one of the transverse mode adjustment conditions described above and functions as a mode loss effect region.

The surface-emitting laser 21 can be manufactured by a method generally similar to the method for manufacturing the surface-emitting laser 21 according to the first embodiment.

Although the surface-emitting laser 21 has a poorer mode loss effect, it achieves substantially the same effect as the surface-emitting laser 11 according to the first embodiment.

(Optical Simulation)
The material of the insulating film 107 having the transverse mode adjustment region TMAA was _SiO2 , D _S /ω was 2.2, D _L /ω was 2.25, the current confinement diameter was 4 μm, the resonator length was 24 μm, and the curvature radius of the concave mirror 102 was 80 μm. As a result, the desired loss could be given to the transverse mode, and the transverse mode could be appropriately adjusted (to the desired single mode).

<12. Surface-emitting laser according to Example 12 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 12 of an embodiment of the present technology will be described with reference to the drawings.

<Configuration of surface-emitting laser>
FIG. 29 is a cross-sectional view of a surface-emitting laser 22 according to Example 12 of an embodiment of the present technology.

As shown in FIG. 29, the surface-emitting laser 22 has a configuration generally similar to that of the surface-emitting laser 11 of Example 1, except that the metal film 110, which serves as an intermediate layer provided between the substrate 104 and the concave mirror 102, has a transverse mode adjustment area TMAA. The metal film 110 preferably has a single-layer or multi-layer configuration including at least one type of metal selected from the group consisting of Au, Ag, Cu, Al, W, Ni, Ti, Pt, Pd, Co, Rh, and Cr.

In the surface-emitting laser 22, the metal film 110 satisfies at least one of the transverse mode adjustment conditions described above and functions as a mode loss effect region.

<Manufacturing method of surface-emitting laser>
The surface emitting laser 22 is manufactured, for example, according to the procedure of the flow chart shown in Fig. 30. Steps S31 to S38 in Fig. 30 are similar to steps S1 to S8 in Fig. 5, respectively.

In step S39, the metal film 110 is formed (see FIG. 31A). Specifically, the metal film 110 is formed on the peripheral portion of the convex structure 104a and on the flat portion around the peripheral portion, for example, by a lift-off method. The metal film 110 is formed by, for example, a vacuum deposition method, a sputtering method, or the like.

In the final step S39.5, the concave mirror 102 is formed (see FIG. 31B). Specifically, the material of the concave mirror 102 (e.g., a dielectric multilayer film) is formed by, for example, vacuum deposition, sputtering, CVD, or the like so as to cover the center of the convex structure 104a and the metal film 110. As a result, the concave mirror 102 is formed in a shape that imitates the convex structure 104a and the metal film 110. This produces a plurality of surface-emitting lasers 22 on a wafer (semiconductor substrate (e.g., n-GaN substrate)). After that, the series of surface-emitting lasers 22 are separated by dicing to obtain chip-shaped surface-emitting lasers 22 (surface-emitting laser chips). The surface-emitting lasers 22 are then mounted, for example, in a CAN package. More specifically, the surface of the surface-emitting laser 22 on the concave mirror 102 side is soldered to the CAN package.

<Effects of surface-emitting lasers>
The surface-emitting laser 22 exhibits the same effects as the surface-emitting laser 11 of Example 1, and the metal film 110 serving as an intermediate layer provided between the substrate 104 and the concave mirror 102 has a transverse mode adjustment region TMAA, making it possible to control the mode while maintaining element characteristics such as the beam diameter, IV characteristics, and reliability.

(Optical Simulation)
When the metal film 110 has the transverse mode adjustment region TMAA, D _S /ω is 2.2, D _L /ω is 2.2, the current confinement diameter is 4 μm, the resonator length is 24 μm, and the curvature radius of the concave mirror 102 is 80 μm. As a result, it is possible to impart a desired loss to the transverse mode, and to properly adjust the transverse mode (to a desired single mode).

<13. Surface-emitting laser according to Example 13 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 13 of an embodiment of the present technology will be described with reference to the drawings.

<Configuration of surface-emitting laser>
FIG. 32 is a cross-sectional view of a surface-emitting laser 23 according to Example 13 of an embodiment of the present technology.

As shown in Fig. 32, the surface-emitting laser 23 has a configuration generally similar to that of the surface-emitting laser 11 of Example 1, except that the metal film 110 provided on the back surface (lower surface) of the concave mirror 102 has a transverse mode adjustment area TMAA. The metal film 110 preferably has a single-layer or multi-layer configuration including at least one type of metal selected from the group consisting of Au, Ag, Cu, Al, W, Ni, Ti, Pt, Pd, Co, Rh, and Cr.

In the surface-emitting laser 23, the metal film 110 satisfies at least one of the transverse mode adjustment conditions described above and functions as a mode loss effect region.

<Manufacturing method of surface-emitting laser>
The surface emitting laser 23 is manufactured, for example, according to the procedure of the flow chart shown in Fig. 33. Steps S41 to S49 in Fig. 33 are similar to steps S1 to S9 in Fig. 5, respectively.

In the final step S49.5, the metal film 110 is formed (see FIG. 32). Specifically, the metal film 110 is formed on the periphery of the concave mirror 102 by, for example, a lift-off method. The metal film 110 is formed by, for example, a vacuum deposition method, a sputtering method, or the like.

<Effects of surface-emitting lasers>
The surface-emitting laser 23 exhibits the same effects as the surface-emitting laser 11 of Example 1, and since the metal film 110 provided on the rear surface of the concave mirror 102 has a transverse mode adjustment region TMAA, mode control becomes possible while maintaining element characteristics such as beam diameter, IV characteristics, and reliability.

(Optical Simulation)
When the metal film 110 has the transverse mode adjustment region TMAA, D _S /ω is 2.2, D _L /ω is 2.2, the current confinement diameter is 4 μm, the resonator length is 24 μm, and the curvature radius of the concave mirror 102 is 80 μm. As a result, it is possible to impart a desired loss to the transverse mode, and to properly adjust the transverse mode (to a desired single mode).

<14. Surface-emitting laser according to Example 14 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 14 of an embodiment of the present technology will be described with reference to the drawings.

<Configuration of surface-emitting laser>
FIG. 34 is a cross-sectional view of a surface-emitting laser 24 according to Example 14 of an embodiment of the present technology.

The surface-emitting laser 24 has a configuration generally similar to that of the surface-emitting laser 11 of Example 1, except that the metal film 110 provided in an annular shape on the periphery of the reflector 103 has a transverse mode adjustment area TMAA, as shown in FIG. 34. The metal film 110 preferably has a single-layer or multi-layer configuration including at least one type of metal selected from the group consisting of Au, Ag, Cu, Al, W, Ni, Ti, Pt, Pd, Co, Rh, and Cr.

In the surface-emitting laser 24, the metal film 110 satisfies at least one of the transverse mode adjustment conditions described above and functions as a mode loss effect region.

<Manufacturing method of surface-emitting laser>
The surface emitting laser 24 is manufactured, for example, according to the procedure of the flow chart shown in Fig. 35. Steps S51 to S57, S59, and S59.5 in Fig. 35 are similar to steps S1 to S7, S8, and S9 in Fig. 5, respectively.

In step S58, the metal film 110 is formed. Specifically, the metal film 110 is formed in a ring shape on the periphery of the reflecting mirror 103 by, for example, a lift-off method. The metal film 110 is formed by, for example, a vacuum deposition method, a sputtering method, or the like.

<Effects of surface-emitting lasers>
The surface-emitting laser 24 exhibits the same effects as the surface-emitting laser 11 of Example 1, and since the metal film 110 provided on the periphery of the reflector 103 has the transverse mode adjustment region TMAA, mode control becomes possible while maintaining element characteristics such as the beam diameter, IV characteristics, and reliability.

(Optical Simulation)
When the metal film 110 has the transverse mode adjustment region TMAA, D _S /ω is 2.2, D _L /ω is 2.2, the current confinement diameter is 4 μm, the resonator length is 24 μm, and the curvature radius of the concave mirror 102 is 80 μm. As a result, it is possible to impart a desired loss to the transverse mode, and to properly adjust the transverse mode (to a desired single mode).

<15. Surface-emitting laser according to Example 15 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to a fifteenth example of an embodiment of the present technology will be described with reference to the drawings.

FIG. 36 is a cross-sectional view of a surface-emitting laser 25 according to Example 15 of an embodiment of the present technology.

The surface-emitting laser 25 has a configuration generally similar to that of the surface-emitting laser 11 of Example 1, except that the metal film 110 provided in a ring shape in a plan view on the periphery and inner wall surface of the reflector 103 has a transverse mode adjustment area TMAA, as shown in Figure 36. The metal film 110 preferably has a single-layer or multi-layer configuration including at least one type of metal selected from the group consisting of Au, Ag, Cu, Al, W, Ni, Ti, Pt, Pd, Co, Rh, and Cr.

In the surface-emitting laser 25, the metal film 110 satisfies at least one of the transverse mode adjustment conditions described above and functions as a mode loss effect region.

The surface-emitting laser 25 can be manufactured by a method generally similar to the method for manufacturing the surface-emitting laser 24 of Example 14.

<Effects of surface-emitting lasers>
The surface-emitting laser 25 exhibits the same effects as the surface-emitting laser 11 of Example 1, and the metal film 110 provided on the peripheral portion and the inner wall surface of the reflector 103 has a transverse mode adjustment region TMAA, making it possible to control the mode while maintaining element characteristics such as the beam diameter, IV characteristics, and reliability.

(Optical Simulation)
When the metal film 110 has the transverse mode adjustment region TMAA, D _S /ω is 2.2, D _L /ω is 2.2, the current confinement diameter is 4 μm, the resonator length is 24 μm, and the curvature radius of the concave mirror 102 is 80 μm. As a result, it is possible to impart a desired loss to the transverse mode, and to properly adjust the transverse mode (to a desired single mode).
<16. Surface-emitting laser according to Example 16 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 16 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 37 is a cross-sectional view of a surface-emitting laser 26 according to Example 16 of an embodiment of the present technology.

In each of the above embodiments, the transverse mode adjustment region TMAA is provided to surround the light emitting region LA in a plan view (so as not to overlap the light emitting region LA) in order to adjust the transverse mode mainly to a single mode, but in the surface emitting laser 26 shown in FIG. 37, a second region A2, which is a part of the transverse mode adjustment region TMAA, is provided to overlap the light emitting region LA in order to adjust the transverse mode mainly to a multimode. Here, the annular first region A1 and the circular second region A2 are arranged concentrically, but they do not have to be arranged concentrically. The size, shape, etc. of the first and second regions A1 and A2 can be changed as appropriate.

(Optical Simulation)
In Example 16, D _S /ω was 2.1, D _L /ω was 2.4, the current confinement diameter was 4 μm, the resonator length was 24 μm, and the curvature radius of the concave mirror 102 was 80 μm. As a result, it was possible to impart a desired loss to the transverse mode, and to properly adjust the transverse mode (to a desired multimode).
<17. Surface-emitting laser according to Example 17 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 17 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 38 is a cross-sectional view of a surface-emitting laser 27 according to Example 17 of an embodiment of the present technology.

In the surface-emitting laser 27, the anode electrode 108 and the ion implantation region IIA have a transverse mode adjustment region TMAA. Here, it is assumed that the transverse mode adjustability of the ion implantation region IIA is high enough to be disregarded compared to the transverse mode adjustability of the anode electrode 108 (for example, the light blocking property of the anode electrode 108 is not very high).

The surface-emitting laser 27 can combine multiple transverse mode adjustment areas TMAA to appropriately adjust the transverse mode.

<18. Surface-emitting laser according to Example 18 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to an eighteenth example of an embodiment of the present technology will be described with reference to the drawings.

FIG. 39A is a plan view of a transverse mode adjustment region of a surface-emitting laser 28 according to Example 18 of an embodiment of the present technology.

The surface-emitting laser 28 has a configuration similar to that of the surface-emitting laser 11 of Example 1, except that the inner edge shape of the first area A1 of the transverse mode adjustment area TMAA is triangular.

The surface-emitting laser 28 provides substantially the same effects as the surface-emitting laser 11 of Example 1.

<19. Surface-emitting laser according to Example 19 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 19 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 39B is a plan view of a transverse mode adjustment region of a surface-emitting laser 29 according to Example 19 of an embodiment of the present technology.

The surface-emitting laser 29 has a configuration similar to that of the surface-emitting laser 11 of Example 1, except that the inner edge shape of the first area A1 of the transverse mode adjustment area TMAA is square.

The surface-emitting laser 29 provides substantially the same effects as the surface-emitting laser 11 of Example 1.

<20. Surface-emitting laser according to Example 20 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 20 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 40A is a plan view of a transverse mode adjustment region of a surface-emitting laser 30 according to Example 20 of an embodiment of the present technology.

The surface-emitting laser 30 has a configuration similar to that of the surface-emitting laser 11 of Example 1, except that the inner edge shape of the first area A1 of the transverse mode adjustment area TMAA is a regular hexagon.

The surface-emitting laser 30 provides substantially the same effects as the surface-emitting laser 11 of Example 1.

<21. Surface-emitting laser according to Example 21 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 21 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 40B is a plan view of the transverse mode adjustment region of a surface-emitting laser 31 according to Example 21 of an embodiment of the present technology.

The surface-emitting laser 31 has a configuration similar to that of the surface-emitting laser 11 of Example 1, except that the inner edge shape of the first area A1 of the transverse mode adjustment area TMAA is a regular octagon.

The surface-emitting laser 31 provides substantially the same effects as the surface-emitting laser 11 of Example 1.

The inner edge shape of the first area A1 of the transverse mode adjustment area TMAA may be a regular polygon having more sides than a regular octagon.

<22. Surface-emitting laser according to Example 22 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 22 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 41A is a plan view of a transverse mode adjustment region of a surface-emitting laser 32 according to Example 22 of an embodiment of the present technology.

The surface-emitting laser 32 has a configuration similar to that of the surface-emitting laser 15 of Example 5, except that the inner edge shape of the first area A1 of the transverse mode adjustment area TMAA is a regular pentagon that has been distorted horizontally.

The surface-emitting laser 32 provides substantially the same effects as the surface-emitting laser 15 of Example 5.

<23. Surface-emitting laser according to Example 23 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 23 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 41B is a plan view of the transverse mode adjustment region of a surface-emitting laser 33 according to Example 23 of an embodiment of the present technology.

The surface-emitting laser 33 has a configuration similar to that of the surface-emitting laser 15 of Example 5, except that the inner edge shape of the first area A1 of the transverse mode adjustment area TMAA is a regular pentagon that has been distorted vertically.

The surface-emitting laser 32 provides substantially the same effects as the surface-emitting laser 15 of Example 5.

The inner edge shape of the first area A1 of the transverse mode adjustment area TMAA may be a distorted regular polygon having more sides than a regular octagon.

<24. Surface-emitting laser according to Example 24 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 24 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 42A is a plan view of a transverse mode adjustment region of a surface-emitting laser 34 according to Example 24 of an embodiment of the present technology.

The surface-emitting laser 34 has a similar configuration to the surface-emitting laser 13 of Example 3, except that the inner edge of the first area A1 of the transverse mode adjustment area TMAA has four convex portions that protrude radially.

The surface-emitting laser 34 provides substantially the same effects as the surface-emitting laser 13 of Example 3.

<25. Surface-emitting laser according to Example 25 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 25 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 42B is a plan view of the transverse mode adjustment region of a surface-emitting laser 35 according to Example 25 of an embodiment of the present technology.

The surface-emitting laser 35 has a similar configuration to the surface-emitting laser 13 of Example 3, except that the inner edge of the first area A1 of the transverse mode adjustment area TMAA has six protrusions that protrude radially.

The surface-emitting laser 35 provides substantially the same effects as the surface-emitting laser 13 of Example 3.

The inner edge of the first area A1 of the transverse mode adjustment area TMAA may have seven or more protrusions that protrude radially.

<26. Surface-emitting laser according to Example 26 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 26 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 43A is a plan view of the transverse mode adjustment region of a surface-emitting laser 36 according to Example 26 of an embodiment of the present technology.

The surface-emitting laser 36 has a similar configuration to the surface-emitting laser 16 of Example 6, except that the second region A2 of the transverse mode adjustment area TMAA has four parts (e.g., circular parts) that are separated from one another. As an example, the four parts that make up the second region A2 are located on the four vertices of a square that surrounds the light-emitting area LA. Here, the center of the square coincides with the center of the annular first region A1, but this does not have to be the case.

The surface-emitting laser 36 provides substantially the same effects as the surface-emitting laser 16 of Example 6.

<27. Surface-emitting laser according to Example 27 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 27 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 43A is a plan view of a transverse mode adjustment region of a surface-emitting laser 37 according to Example 27 of an embodiment of the present technology.

The surface-emitting laser 37 has a similar configuration to the surface-emitting laser 16 of Example 6, except that the second area A2 of the transverse mode adjustment area TMAA has two parts (e.g., circular parts) that are separated from each other. As an example, the two parts constituting the second area A2 are arranged at positions sandwiching the light-emitting area LA in a planar view. Here, the midpoint of the two parts coincides with the center of the annular first area A1, but this does not have to be the case.

The surface-emitting laser 37 provides substantially the same effects as the surface-emitting laser 16 of Example 6.

The second area A2 of the transverse mode adjustment area TMAA may have five or more parts that are separated from each other and arranged two-dimensionally.

<28. Surface-emitting laser according to Example 28 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 28 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 44A is a plan view of a transverse mode adjustment region of a surface-emitting laser 38 according to Example 28 of an embodiment of the present technology.

The surface-emitting laser 38 has a similar configuration to the surface-emitting laser 17 of Example 7, except that the second region A2 of the transverse mode adjustment area TMAA is an equilateral triangular frame surrounding the light-emitting area LA in a plan view. Here, the center of the second region A2 coincides with the center of the annular first region A1, but they do not have to coincide.

The surface-emitting laser 38 provides substantially the same effects as the surface-emitting laser 17 of Example 7.

<29. Surface-emitting laser according to Example 29 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 29 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 44B is a plan view of the transverse mode adjustment region of a surface-emitting laser 39 according to Example 29 of an embodiment of the present technology.

The surface-emitting laser 39 has a similar configuration to the surface-emitting laser 17 of Example 7, except that the second region A2 of the transverse mode adjustment area TMAA is a square frame surrounding the light-emitting area LA in a plan view. Here, the center of the second region A2 coincides with the center of the annular first region A1, but they do not have to coincide.

The surface-emitting laser 39 provides substantially the same effects as the surface-emitting laser 17 of Example 7.

<30. Surface-emitting laser according to Example 30 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 30 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 45A is a plan view of a transverse mode adjustment region of a surface-emitting laser 40 according to Example 30 of an embodiment of the present technology.

The surface-emitting laser 40 has a similar configuration to the surface-emitting laser 17 of Example 7, except that the second region A2 of the transverse mode adjustment area TMAA is a pentagonal frame surrounding the light-emitting area LA in a planar view. Here, the center of the second region A2 coincides with the center of the annular first region A1, but they do not have to coincide.

The surface-emitting laser 40 provides substantially the same effects as the surface-emitting laser 17 of Example 7.

<31. Surface-emitting laser according to Example 31 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 31 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 45B is a plan view of a transverse mode adjustment region of a surface-emitting laser 41 according to Example 31 of an embodiment of the present technology.

The surface-emitting laser 41 has a similar configuration to the surface-emitting laser 17 of Example 7, except that the second region A2 of the transverse mode adjustment area TMAA is a hexagonal frame surrounding the light-emitting area LA in a planar view. Here, the center of the second region A2 coincides with the center of the annular first region A1, but they do not have to coincide.

The surface-emitting laser 41 provides substantially the same effects as the surface-emitting laser 17 of Example 7.

The second area A2 of the transverse mode adjustment area TMAA may be in the shape of a regular polygonal frame having more sides than a regular hexagon.

<32. Surface-emitting laser according to Example 32 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 32 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 46A is a plan view of a transverse mode adjustment region of a surface-emitting laser 42 according to Example 32 of an embodiment of the present technology.

The surface-emitting laser 42 has a similar configuration to the surface-emitting laser 17 of Example 7, except that the inner edge shape of the first region A1 of the transverse mode adjustment area TMAA is elliptical, and the second region A2 is an elliptical frame surrounding the light-emitting area LA in a planar view. Here, the center of the second region A2 and the center of the first region A1 coincide with each other, but they do not have to coincide with each other.

The surface-emitting laser 42 provides substantially the same effects as the surface-emitting laser 17 of Example 7.

<33. Surface-emitting laser according to Example 33 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 33 of an embodiment of the present technology will be described with reference to the drawings.

FIG. 46B is a plan view of the transverse mode adjustment region of a surface-emitting laser 43 according to Example 33 of an embodiment of the present technology.

The surface-emitting laser 43 has a similar configuration to the surface-emitting laser 17 of Example 7, except that the inner edge shape of the second region A2 of the transverse mode adjustment area TMAA is circular, and the second region A2 is an elliptical frame surrounding the light-emitting area LA in a plan view. Here, the center of the second region A2 coincides with the center of the annular first region A1, but they do not have to coincide.

The surface-emitting laser 43 provides substantially the same effects as the surface-emitting laser 17 of Example 7.

The second region A2 of the transverse mode adjustment region TMAA may have multiple concentric and/or substantially similar portions.

<34. Surface-emitting laser according to Example 34 of an embodiment of the present technology>
Hereinafter, a surface emitting laser according to Example 34 of an embodiment of the present technology will be described with reference to the drawings.

<Configuration of surface-emitting laser>
FIG. 47 is a cross-sectional view of a surface-emitting laser 44 according to Example 34 of an embodiment of the present technology.

As shown in FIG. 47, the surface-emitting laser 34 has a configuration generally similar to that of the surface-emitting laser 23 of Example 13, except that a metal film having a transverse mode adjustment region TMAA is provided across the back surface (lower surface) of the concave mirror 102 and the back surface (lower surface) of the substrate 104. In the surface-emitting laser 34, the metal film having the transverse mode adjustment region TMAA also serves as the cathode electrode 109. In other words, the metal film serving as the cathode electrode 109 has a transverse mode adjustment region.

In the surface-emitting laser 23, the metal film serving as the cathode electrode 109 satisfies at least one of the transverse mode adjustment conditions described above and functions as a mode loss effect region.

<Manufacturing method of surface-emitting laser>
The surface emitting laser 34 can be manufactured by a method substantially similar to the method for manufacturing the surface emitting laser 23 according to the thirteenth embodiment.

<Effects of surface-emitting lasers>
The surface-emitting laser 34 exhibits the same effects as the surface-emitting laser 11 of Example 1, and the metal film serving as the cathode electrode 109 provided across the rear surface of the concave mirror 102 and the rear surface of the substrate 104 has a transverse mode adjustment area TMAA, making it possible to control the mode while maintaining element characteristics such as the beam diameter, IV characteristics, and reliability.

(Optical Simulation)
When the metal film had the transverse mode adjustment region TMAA, D _S /ω was 2.2, D _L /ω was 2.2, the current confinement diameter was 4 μm, the resonator length was 24 μm, and the curvature radius of the concave mirror 102 was 80 μm. As a result, it was possible to impart a desired loss to the transverse mode, and to properly adjust the transverse mode (to a desired single mode).

<35. Modifications of the present technology>
The present technology is not limited to the above-described embodiments, and various modifications are possible. For example, the surface-emitting laser according to the above-described embodiments is a GaN-based VCSEL, but the present technology is not limited thereto, and is applicable to all VCSELs made of III-V group compound semiconductors. For example, the present technology is also applicable to GaAs-based VCSELs and InP-based VCSELs.

The inner edge shape of the first region and the inner edge shape and outer edge shape of the second region of the transverse mode adjustment region are not limited to the above examples and can be changed as appropriate.

The transverse mode tuning region may be made of, for example, a semiconductor material or an organic material.

The surface-emitting laser according to this technology does not need to have the insulating film 107.

The current confinement region may be made of an insulating material such as polyimide.

Parts of the configurations of the surface-emitting lasers in each of the above embodiments may be combined within the limits of not mutually contradicting each other.

In the surface-emitting lasers according to each embodiment, the conductivity types (p-type and n-type) may be interchanged.

It is also possible to configure a surface-emitting laser array in which the surface-emitting lasers according to each embodiment are arranged in an array.

In each of the embodiments and modifications described above, the material, thickness, width, length, shape, size, arrangement, etc. of each component that makes up the surface-emitting laser can be changed as appropriate within the range that allows the surface-emitting laser to function.

<36. Application examples to electronic devices>
The technology according to the present disclosure (the present technology) can be applied to various products (electronic devices). For example, the technology according to the present disclosure may be realized as a device (e.g., a distance measuring device, a shape recognition device, etc.) mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility, an airplane, a drone, a ship, a robot, etc.

The surface-emitting laser according to this technology can also be used as a light source or the display itself for devices that form or display images using laser light (e.g. laser printers, laser copiers, projectors, head-mounted displays, head-up displays, etc.).

<37. Example of application of surface emitting laser to distance measuring device>
Application examples of the surface emitting lasers according to the above embodiments and modifications will be described below.

FIG. 48 shows an example of the schematic configuration of a distance measuring device 1000 (distance measuring device) equipped with a surface emitting laser 11, as an example of electronic equipment related to the present technology. The distance measuring device 1000 measures the distance to a subject S using a TOF (Time Of Flight) method. The distance measuring device 1000 is equipped with a surface emitting laser 11 as a light source. The distance measuring device 1000 is equipped with, for example, the surface emitting laser 11, a light receiving device 125, lenses 117, 130, a signal processing unit 140, a control unit 150, a display unit 160, and a memory unit 170.

The surface-emitting laser 11 is driven by a laser driver (driver). The laser driver has an anode terminal and a cathode terminal that are connected to the anode electrode and cathode electrode of the surface-emitting laser 11 via wiring, respectively. The laser driver is configured to include circuit elements such as capacitors and transistors.

The light receiving device 125 detects the light reflected by the subject S. The lens 117 is a collimating lens that converts the light emitted from the surface-emitting laser 11 into parallel light. The lens 130 is a focusing lens that collects the light reflected by the subject S and guides it to the light receiving device 125.

The signal processing unit 140 is a circuit for generating a signal corresponding to the difference between the signal input from the light receiving device 125 and the reference signal input from the control unit 150. The control unit 150 is configured to include, for example, a Time to Digital Converter (TDC). The reference signal may be a signal input from the control unit 150, or may be an output signal of a detection unit that directly detects the output of the surface emitting laser 11. The control unit 150 is, for example, a processor that controls the surface emitting laser 11, the light receiving device 125, the signal processing unit 140, the display unit 160, and the storage unit 170. The control unit 150 is a circuit that measures the distance to the specimen S based on the signal generated by the signal processing unit 140. The control unit 150 generates a video signal for displaying information about the distance to the specimen S and outputs it to the display unit 160. The display unit 160 displays information about the distance to the specimen S based on the video signal input from the control unit 150. The control unit 150 stores the information about the distance to the specimen S in the storage unit 170.

In this application example, instead of the surface-emitting laser 11, any one of the surface-emitting lasers 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, and 44 can be applied to the distance measurement device 1000. When a surface-emitting laser having a plurality of element portions is applied to the distance measurement device 1000, a driver capable of driving the plurality of element portions individually can also be used.
<38. Example of distance measuring device installed on a moving object>

FIG. 49 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile object control system to which the technology disclosed herein can be applied.

The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in FIG. 49, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside vehicle information detection unit 12030, an inside vehicle information detection unit 12040, and an integrated control unit 12050. Also shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio/video output unit 12052, and an in-vehicle network I/F (interface) 12053.

The drive system control unit 12010 controls the operation of devices related to the drive system of the vehicle according to various programs. For example, the drive system control unit 12010 functions as a control device for a drive force generating device for generating the drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force for the vehicle.

The body system control unit 12020 controls the operation of various devices installed in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, tail lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves or signals from various switches transmitted from a portable device that replaces a key can be input to the body system control unit 12020. The body system control unit 12020 accepts the input of these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, a distance measurement device 12031 is connected to the outside-vehicle information detection unit 12030. The distance measurement device 12031 includes the distance measurement device 1000 described above. The outside-vehicle information detection unit 12030 causes the distance measurement device 12031 to measure the distance to an object outside the vehicle (subject S), and acquires the distance data obtained thereby. The outside-vehicle information detection unit 12030 may perform object detection processing of people, cars, obstacles, signs, etc. based on the acquired distance data.

The in-vehicle information detection unit 12040 detects information inside the vehicle. To the in-vehicle information detection unit 12040, for example, a driver state detection unit 12041 that detects the state of the driver is connected. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the driver's degree of fatigue or concentration based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

The microcomputer 12051 can calculate control target values for the driving force generating device, steering mechanism, or braking device based on information inside and outside the vehicle acquired by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the distance between vehicles, maintaining vehicle speed, vehicle collision warning, or vehicle lane departure warning.

The microcomputer 12051 can also control the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle acquired by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040, thereby performing cooperative control aimed at automatic driving, which allows the vehicle to travel autonomously without relying on the driver's operation.

The microcomputer 12051 can also output control commands to the body system control unit 12020 based on information outside the vehicle acquired by the outside-vehicle information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside-vehicle information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching high beams to low beams.

The audio/image output unit 12052 transmits at least one output signal of audio and image to an output device capable of visually or audibly notifying the occupants of the vehicle or the outside of the vehicle of information. In the example of FIG. 49, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are exemplified as output devices. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

Figure 50 shows an example of the installation location of the distance measuring device 12031.

In FIG. 50, the vehicle 12100 has distance measurement devices 12101, 12102, 12103, 12104, and 12105 as the distance measurement device 12031.

The distance measuring devices 12101, 12102, 12103, 12104, and 12105 are provided, for example, on the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of the vehicle 12100. The distance measuring device 12101 provided on the front nose and the distance measuring device 12105 provided on the top of the windshield inside the vehicle cabin mainly obtain data in front of the vehicle 12100. The distance measuring devices 12102 and 12103 provided on the side mirrors mainly obtain data on the sides of the vehicle 12100. The distance measuring device 12104 provided on the rear bumper or back door mainly obtains data on the rear of the vehicle 12100. The forward data obtained by the distance measuring devices 12101 and 12105 is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, etc.

Note that FIG. 50 shows an example of the detection ranges of distance measuring devices 12101 to 12104. Detection range 12111 indicates the detection range of distance measuring device 12101 provided on the front nose, detection ranges 12112 and 12113 indicate the detection ranges of distance measuring devices 12102 and 12103 provided on the side mirrors, respectively, and detection range 12114 indicates the detection range of distance measuring device 12104 provided on the rear bumper or back door.

For example, the microcomputer 12051 can determine the distance to each three-dimensional object within the detection ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100) based on the distance data obtained from the distance measuring devices 12101 to 12104, and can extract as a preceding vehicle, in particular, the closest three-dimensional object on the path of the vehicle 12100 that is traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km/h or faster). Furthermore, the microcomputer 12051 can set the inter-vehicle distance that should be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control) and automatic acceleration control (including follow-up start control). In this way, cooperative control can be performed for the purpose of automatic driving, which runs autonomously without relying on the driver's operation.

For example, the microcomputer 12051 classifies and extracts three-dimensional object data on three-dimensional objects, such as two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects, based on the distance data obtained from the distance measuring devices 12101 to 12104, and can use the data to automatically avoid obstacles. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines the collision risk, which indicates the degree of risk of collision with each obstacle, and when the collision risk is equal to or exceeds a set value and there is a possibility of a collision, it can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by forcibly decelerating or steering to avoid a collision via the drive system control unit 12010.

The above describes an example of a mobile object control system to which the technology disclosed herein can be applied. The technology disclosed herein can be applied to the distance measuring device 12031 of the configuration described above.

The present technology can also be configured as follows.
(1) an active layer;
a first structure having a concave mirror disposed on one side of the active layer;
a second structure having a reflector disposed on the other side of the active layer;
Equipped with
a transverse mode adjustment region is provided in the first structure and/or the second structure;
the transverse mode adjustment region has at least the first region of the first and second regions, when a region surrounding a light emitting region of the active layer in a plan view is defined as a first region and a region surrounded by the first region is defined as a second region,
When the transverse mode adjustment region has only the first region of the first and second regions, the shortest distance from the center of gravity of the transverse mode adjustment region to the inner edge of the first region is defined as D _S and the longest distance is defined as D _L ;
When the transverse mode adjustment region has the first and second regions, the shortest distance from the areal center of gravity of the transverse mode adjustment region to the inner edge of the first region and the outer edge of the second region is denoted by D _S and the longest distance is denoted by D _L .
A surface emitting laser in which 1≦D _L /D _S ≦10 is satisfied.
(2) The surface-emitting laser according to (1), wherein the first structure and/or the second structure is provided with a current confinement region that sets the light-emitting region.
(3) The surface emitting laser according to (1) or (2), in which 1≦D _L /D _S ≦6 is satisfied.
(4) The surface-emitting laser according to any one of (1) to (3), wherein 1≦D _L /D _S ≦3 is satisfied.
(5) The surface-emitting laser according to any one of (1) to (4), wherein 0.5≦D _S /ω≦6 and 0.5≦D _L /ω≦12 are satisfied.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius L _m : Vertical distance from the beam waist to the transverse mode adjustment region n: Refractive index of the medium λ ₀ : Oscillation wavelength of the surface-emitting laser (6) The surface-emitting laser according to any one of (1) to (5), in which 1≦D _S /ω≦3 and 1≦D _L /ω≦12 are satisfied.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius L _m : Vertical distance from the beam waist to the transverse mode adjustment region n: Refractive index of the medium λ ₀ : Oscillation wavelength of the surface-emitting laser (7) The surface-emitting laser according to any one of (1) to (6), in which 0.5≦D _S /ω≦6 and 1≦D _L /ω≦6 are satisfied.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius L _m : Vertical distance from the beam waist to the transverse mode adjustment region n : Refractive index of the medium λ ₀ : Oscillation wavelength of the surface-emitting laser (8) The surface-emitting laser according to any one of (1) to (7), wherein the second structure has an electrode arranged on the other side of the active layer, and the electrode has the transverse mode adjustment region.
(9) The surface-emitting laser according to any one of (1) to (8), wherein the first structure has an electrode disposed on the one side of the active layer, the electrode having the transverse mode adjustment region.
(10) The surface-emitting laser according to any one of (1) to (9), wherein the concave mirror has the transverse mode adjustment region.
(11) The surface-emitting laser according to any one of (1) to (10), wherein the reflecting mirror has the transverse mode adjustment region.
(12) The surface-emitting laser according to any one of (1) to (11), wherein the second structure has the transverse mode adjustment region on the opposite side of the reflector to the active layer.
(13) The surface-emitting laser according to any one of (1) to (12), wherein the first structure has the transverse mode adjustment region on a side of the concave mirror opposite to the active layer side.
(14) The surface-emitting laser according to any one of (1) to (13), wherein the first structure has the transverse mode adjustment region between the concave mirror and the active layer.
(15) The surface-emitting laser according to any one of (1) to (14), wherein the second structure has the transverse mode adjustment region between the reflector and the active layer.
(16) The surface-emitting laser according to any one of (2) to (15), wherein the current confinement region has the transverse mode adjustment region.
(17) The surface-emitting laser according to any one of (1) to (16), wherein the second structure has an insulating film arranged on the other side of the active layer, the insulating film having the transverse mode adjustment region.
(18) A surface-emitting laser according to any one of (1) to (17), wherein the first structure has a substrate disposed between the concave mirror and the active layer, and an intermediate layer disposed between the concave mirror and the substrate, the intermediate layer having the transverse mode adjustment region.
(19) The surface-emitting laser according to any one of (1) to (18), wherein the first region and/or the second region includes a plurality of microstructures.
(20) The surface-emitting laser according to any one of (1) to (19), wherein the transverse mode adjustment region is made of any one of a metal material, an alloy material, a dielectric material, a semiconductor material, and an organic material.
(21) The surface-emitting laser according to any one of (1) to (20), wherein the shape of the inner edge of the first region is substantially circular or substantially regular polygonal.
(22) The surface-emitting laser according to any one of (1) to (20), wherein the shape of the inner edge of the first region is a distorted circle or a distorted regular polygon.
(23) The surface-emitting laser according to any one of (1) to (22), wherein an inner edge of the first region has a plurality of protrusions protruding radially toward an outer edge side of the first region.
(24) The surface-emitting laser according to any one of (1) to (23), wherein the transverse mode adjustment region has the first and second regions, and the second region has a plurality of portions separated from each other.
(25) The surface-emitting laser according to (24), wherein the plurality of portions are at least three portions, and the at least three portions are two-dimensionally arranged at a predetermined pitch in a plan view.
(26) A surface-emitting laser described in any one of (1) to (25), wherein the lateral mode adjustment region has the first and second regions, and the second region has at least one region that is approximately similar to the first region in a planar view.
(27) A surface-emitting laser described in any one of (1) to (26), wherein the lateral mode adjustment region has the first and second regions, and the second region has at least one region arranged approximately concentrically with the first region in a planar view.
(28) The surface-emitting laser according to any one of (1) to (27), wherein the cavity length is 50 μm or less.
(29) The surface-emitting laser according to any one of (1) to (28), wherein the transverse mode adjustment region is made of any one of a metal material, an alloy material, a dielectric material, a semiconductor material, and an organic material.
(30) The surface-emitting laser according to any one of (1) to (29), wherein the transverse mode adjustment region is made of a metal material or an alloy material.
(31) The surface-emitting laser according to any one of (1) to (30), wherein the transverse mode adjustment regions are provided in a plurality of regions.
(32) The surface-emitting laser according to any one of (1) to (31), wherein 1≦D _S /ω≦3 and 1≦D _L /ω≦6 are satisfied.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius L _m : Vertical distance from the beam waist to the transverse mode adjustment region n: Refractive index of the medium λ ₀ : Oscillation wavelength of the surface-emitting laser (33) The surface-emitting laser according to any one of (1) to (32), wherein 1≦D _S /ω≦2.5 and 1≦D _L /ω≦6 are satisfied.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius L _m : Vertical distance from the beam waist to the transverse mode adjustment region n: Refractive index of the medium λ ₀ : Oscillation wavelength of the surface-emitting laser (34) The surface-emitting laser according to any one of (1) to (33), wherein 1≦D _S /ω≦3 and 1≦D _L /ω≦4 are satisfied.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius L _m : Vertical distance from the beam waist to the transverse mode adjustment region n: Refractive index of the medium λ ₀ : Oscillation wavelength of the surface-emitting laser (35) The surface-emitting laser according to any one of (1) to (34), wherein 1≦D _S /ω≦2.5 and 1≦D _L /ω≦4 are satisfied.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius L _m : Vertical distance from the beam waist to the transverse mode adjustment region n: Refractive index of the medium λ ₀ : Oscillation wavelength of the surface-emitting laser (36) The surface-emitting laser according to any one of (1) to (35), wherein 1≦D _S /ω≦2.5 and 1≦D _L /ω≦3 are satisfied.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius L _m : Vertical distance from the beam waist to the transverse mode adjustment region n: Refractive index of the medium λ ₀ : Oscillation wavelength of the surface-emitting laser (37) An electronic device comprising the surface-emitting laser according to any one of (1) to (36).

11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44... Surface-emitting laser 101: active layer 102: concave mirror 103: reflecting mirror 104: substrate 108: anode electrode (electrode)
109: Cathode electrode (electrode)
110: Metal film TMAA: Transverse mode adjustment region A1: First region A2: Second region LA: Light emitting region ST1: First structure ST2: Second structure IIA: Ion implantation region (current confinement region)
C: Area center of gravity

Claims (20)

An active layer;
a first structure having a concave mirror disposed on one side of the active layer;
a second structure having a reflector disposed on the other side of the active layer;
Equipped with
a transverse mode adjustment region is provided in the first structure and/or the second structure;
the transverse mode adjustment region has at least the first region of the first and second regions, when a region surrounding a light emitting region of the active layer in a plan view is defined as a first region and a region surrounded by the first region is defined as a second region,
When the transverse mode adjustment region has only the first region of the first and second regions, the shortest distance from the center of gravity of the transverse mode adjustment region to the inner edge of the first region is defined as D _S and the longest distance is defined as D _L ;
When the transverse mode adjustment region has the first and second regions, the shortest distance from the areal center of gravity of the transverse mode adjustment region to the inner edge of the first region and the outer edge of the second region is denoted by D _S and the longest distance is denoted by D _L .
A surface emitting laser in which 1≦D _L /D _S ≦10 is satisfied. The surface-emitting laser according to claim 1, wherein the first structure and/or the second structure is provided with a current confinement region that sets the light-emitting region. 2. The surface emitting laser according to claim 1, wherein 1≦D _L /D _S ≦6 is satisfied. 2. The surface emitting laser according to claim 1, wherein 1≦D _L /D _S ≦3 is satisfied. 2. The surface emitting laser according to claim 1, wherein 0.5≦D _S /ω≦6 and 0.5≦D _L /ω≦12 are satisfied.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius L _m : Vertical distance from the beam waist to the transverse mode adjustment region n : Refractive index of the medium λ ₀ : Oscillation wavelength of the surface emitting laser 2. The surface emitting laser according to claim 1, wherein 1≦D _S /ω≦3 and 1≦D _L /ω≦12 are satisfied.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius L _m : Vertical distance from the beam waist to the transverse mode adjustment region n : Refractive index of the medium λ ₀ : Oscillation wavelength of the surface emitting laser 2. The surface emitting laser according to claim 1, wherein 0.5≦D _S /ω≦6 and 1≦D _L /ω≦6 are satisfied.
where ω=ω ₀ [(1+(L _m /z) ² ] ^1/2 , z=πnω ₀ ² /λ ₀
ω ₀ : Beam waist radius L _m : Vertical distance from the beam waist to the transverse mode adjustment region n : Refractive index of the medium λ ₀ : Oscillation wavelength of the surface emitting laser the second structure has an electrode disposed on the other side of the active layer;
2. The surface emitting laser of claim 1, wherein the electrode comprises the transverse mode tuning region. the first structure having an electrode disposed on the one side of the active layer;
2. The surface emitting laser of claim 1, wherein the electrode comprises the transverse mode tuning region. The surface-emitting laser of claim 1, wherein the concave mirror has the transverse mode adjustment region. The surface-emitting laser of claim 1, wherein the reflector has the transverse mode adjustment region. The surface-emitting laser according to claim 1, wherein the second structure has the transverse mode adjustment region on the side of the reflector opposite to the active layer. The surface-emitting laser according to claim 1, wherein the first structure has the transverse mode adjustment region on the side of the concave mirror opposite the active layer. The surface-emitting laser according to claim 1, wherein the first structure has the transverse mode adjustment region between the concave mirror and the active layer. The surface-emitting laser of claim 1, wherein the second structure has the transverse mode adjustment region between the reflector and the active layer. The surface-emitting laser according to claim 2, wherein the current confinement region includes the transverse mode adjustment region. the second structure has an insulating film disposed on the other side of the active layer;
2. The surface emitting laser according to claim 1, wherein the insulating film has the transverse mode adjustment region. The first structure is
a substrate disposed between the concave mirror and the active layer;
an intermediate layer disposed between the concave mirror and the substrate;
having
2. The surface emitting laser of claim 1, wherein the intermediate layer comprises the transverse mode tuning region. The surface-emitting laser of claim 1, wherein the first region and/or the second region includes a plurality of microstructures. The surface-emitting laser according to claim 1, wherein the transverse mode adjustment region is made of any one of a metal material, an alloy material, a dielectric material, a semiconductor material, and an organic material.