Vertical-cavity surface-emitting laser

Abstract

A vertical-cavity surface-emitting laser comprises: a first multilayer film reflection mirror (13) which is formed on a substrate (11); a first semiconductor layer (14) of a first conductivity type, which is formed on the first multilayer film reflection mirror (13) and has, in a top view, a first region (14C) that is a central protrusion and a second region (14P) that is an outer peripheral recess around the first region; an active layer (15) which is formed on the first region of the first semiconductor layer; a second semiconductor layer (16) of a second conductivity type, which is formed on the active layer (15) and has, in a top view, a central region (16C) that is a protrusion having an n-sided polygonal shape (in particular, an equilateral triangular shape) and an outer peripheral region (16P) that is an outer peripheral recess around the central region; a light‑transmissive conductive layer (18) which is formed on the central region (16C) of the second semiconductor layer; and a second multilayer film reflection mirror (21) which is formed on the light‑transmissive conductive layer (18). The second multilayer film reflection mirror (21) has, in a top view: a central reflection region (21C) that is a central protrusion formed by a step (21S) of an equilateral triangular which has a shape coaxial and similar to the central region of the second semiconductor layer and which has sides parallel to the respective sides of the central region; and an outer peripheral reflection region (21P) that is an outer peripheral recess. A high-resistance layer (16H) having a resistance higher than that of the second semiconductor layer (16) is provided on the surface of the outer peripheral region (16P) of the second semiconductor layer (16).

Description

Vertical-cavity surface-emitting laser

[0001] The present invention relates to a vertical-cavity surface-emitting laser, particularly a vertical-cavity surface-emitting laser made of a nitride semiconductor.

[0002] Conventionally, a vertical-cavity light-emitting element such as a vertical-cavity surface-emitting laser (VCSEL: vertical cavity surface emitting laser) having a structure that resonates light perpendicular to the substrate surface and emits light in a direction perpendicular to the substrate surface is known.

[0003] For example, Patent Document 1 discloses a vertical-cavity light-emitting element having a first multilayer mirror, a first semiconductor layer formed on the first multilayer mirror, a light-emitting layer formed on the first semiconductor layer, a second semiconductor layer having a low-resistance region and a high-resistance region, and a second multilayer mirror formed on the second semiconductor layer.

[0004] Further, Patent Document 2 discloses a vertical-cavity light-emitting element having a semiconductor structure layer including a light-emitting layer, first and second multilayer mirrors constituting a resonator, and a current constriction layer that constricts a current path in the semiconductor structure layer, the current constriction layer having a current constriction portion with an aperture diameter of 5.5 μm or less.

[0005] Further, Patent Document 3 discloses a vertical-cavity light-emitting element having a light-emitting structure layer including a light-emitting layer and first and second multilayer mirrors constituting a resonator, the light-emitting structure layer including an annular low-resistance region.

[0006] Japanese Unexamined Patent Application Publication No. 2020-64994, Japanese Unexamined Patent Application Publication No .2019-208004, Japanese Unexamined Patent Application Publication No. 2020-64993

[0007] In the vertical-cavity light-emitting element as described above, when the current injection aperture (current injection region) is expanded, it operates in a transverse multimode, and the beam is split into two or more or becomes donut-shaped. Therefore, for example, in a VCSEL element, in order to obtain a transverse single mode, it was necessary to reduce the diameter of the oxidation constriction aperture (for example, 4-5 μm or less).

[0008] However, in vertical resonator type light-emitting elements operating in transverse single mode, the aperture area is smaller compared to the current injection aperture of multimode operating elements, which leads to a problem of significantly reduced optical output.

[0009] The present invention aims to provide a vertical-cavity surface-emitting laser made of a nitride semiconductor that achieves multimode operation in the longitudinal mode (oscillation wavelength), maintains transverse single-mode operation from low to high injection currents, and provides high optical output.

[0010] A vertical-cavity surface-emitting laser according to one embodiment of the present invention is a vertical-cavity surface-emitting laser made of a nitride semiconductor, comprising: a substrate; a first multilayer mirror formed on the substrate; a first semiconductor layer of a first conductivity type formed on the first multilayer mirror and having a first region which is a central convex portion and a second region which is an outer recess of the first region when viewed from above; an active layer formed on the first region of the first semiconductor layer; a second semiconductor layer of a second conductivity type formed on the active layer and having a central region which is an n-sided convex portion (where n is an integer of 3 or more) and an outer recess of the central region when viewed from above; a translucent conductive layer formed on the central region of the second semiconductor layer; and a second multilayer mirror formed on the translucent conductive layer, wherein a high-resistance layer with higher resistance than the second semiconductor layer is provided on the surface of the outer region of the second semiconductor layer.

[0011] This is a schematic cross-sectional view of the vertical-cavity surface-emitting laser (VCSEL) of Example 1. This is a schematic plan view of the top surface of the surface-emitting laser. This is a diagram showing a part of the cross-sectional view of Figure 1, and is a cross-sectional view showing the configuration of the p-type semiconductor layer. This is a schematic cross-sectional view of the resonator of the surface-emitting laser. This is a plan view showing the current injection region (current injection aperture), i.e., the light-emitting regions E1, E2, and E3 within the central region of the p-type semiconductor layer. This is a graph showing the optical output-current characteristics in CW operation of the surface-emitting laser. This is a diagram showing the near-field image FFP and far-field image FFP when the injection current I is 4 mA and 5 mA. This is a diagram showing the optical spectrum when the injection current I is 4 mA and 5 mA.

[0012] Preferred embodiments of the present invention will be described below, but these may be modified and combined as appropriate. In the following description and accompanying drawings, substantially identical or equivalent parts will be denoted by the same reference numerals.

[0013] (1) Structure of a vertical cavity surface-emitting laser Figure 1 is a schematic cross-sectional view showing the structure of a vertical cavity surface-emitting laser (VCSEL: vertical cavity surface-emitting laser, hereinafter referred to as a surface-emitting laser) 10, which is Embodiment 1 of the present invention. Figure 2 is a schematic plan view showing the top surface of the surface-emitting laser 10. Note that Figure 1 shows a cross-section along line A-A in Figure 2.

[0014] The surface-emitting laser 10 of Example 1 is a vertical-cavity surface-emitting laser (VCSEL) made of a gallium nitride (GaN) semiconductor, which is a group III nitride. The surface-emitting laser 10 includes a substrate 11, a first mirror 13 which is a multilayer mirror (DBR: Distributed Bragg Reflector) formed on the substrate 11, and an n-type semiconductor layer 14 (first semiconductor layer of first conductivity type) formed on the first mirror 13.

[0015] On the n-type semiconductor layer 14, an active layer 15, a p-type semiconductor layer 16 (a second semiconductor layer with a second conductivity type opposite to that of the first semiconductor layer), and a translucent conductive layer 18 are formed in this order.

[0016] Furthermore, a translucent spacer layer 19 and a second reflecting mirror 21, which is a multilayer reflecting mirror (DBR), are formed on the translucent conductive layer 18 in this order.

[0017] In the surface-emitting laser 10 of Example 1, the substrate 11 is a gallium nitride (GaN) substrate, and the above-mentioned semiconductor layer is formed by epitaxial growth on the substrate 11, for example, by the MOCVD method (metal-organic vapor deposition).

[0018] Furthermore, an anti-reflective coating layer 12 (AR coating layer) is formed on the back surface of the substrate 11, and the synchrotron radiation from the active layer 15 is emitted from the back surface of the substrate 11.

[0019] The first reflector 13 is an n-type semiconductor reflector (n-DBR) with an optical film thickness of 1 / 4 wavelength, formed by alternately stacking layers with different refractive indices. The first reflector 13 has a structure in which 50 to 60 pairs of low refractive index layers 13A, which are AlInN layers, and high refractive index layers 13B, which are GaN layers, are stacked.

[0020] The n-type semiconductor layer 14 has an n-GaN composition and is doped with, for example, silicon (Si) as an n-type impurity.

[0021] The active layer 15 has a multiple quantum well (MQW) structure and is composed of, for example, multiple GaInN quantum well layers and a GaN barrier layer. The active layer 15 emits, for example, blue light with a wavelength of 445 nm. The active layer 15 may also have a strained multiple quantum well structure.

[0022] The p-type semiconductor layer 16 has a p-GaN composition and is doped with, for example, magnesium (Mg) as a p-type impurity.

[0023] In other words, the n-type semiconductor layer 14, the p-type semiconductor layer 16, and the active layer 15 provided between the n-type semiconductor layer 14 and the p-type semiconductor layer 16 constitute a light-emitting structure layer. The configuration of the light-emitting structure layer is not limited to this.

[0024] For example, the n-type semiconductor layer 14 (first semiconductor layer) may have multiple semiconductor layers with different compositions. The n-type semiconductor layer 14 may also have an undoped layer (or i-layer). Similarly, the p-type semiconductor layer 16 (second semiconductor layer) may have multiple semiconductor layers with different compositions, and may also have an undoped layer (or i-layer). For example, the n-type semiconductor layer 14 and the p-type semiconductor layer 16 may include a carrier block layer or the like. For example, the n-type semiconductor layer 14 may include an electron barrier layer made of AlGaN or the like.

[0025] As shown in Figure 2, the n-type semiconductor layer 14 has a circular step 14S when viewed from above. That is, the n-type semiconductor layer 14 has a first region 14C (central region), which is a circular central convex portion, and a second region 14P (outer region), which is an outer recess of the first region 14C. The first region 14C is the region corresponding to the step 14S. The surface of the first region 14C is flat, and the first region 14C has a circular shape. Note that the first region 14C of the n-type semiconductor layer 14 may be triangular or rectangular when viewed from above.

[0026] Furthermore, an n-electrode 23 (first electrode) electrically connected to the n-type semiconductor layer 14 is provided on the second region 14P of the n-type semiconductor layer 14. The n-electrode 23 is preferably annular in shape.

[0027] Figure 3 is a diagram showing a part of the cross-sectional view of Figure 1, and is a cross-sectional view showing the structure of the p-type semiconductor layer 16.

[0028] The p-type semiconductor layer 16 has a triangular step 16S when viewed from above. That is, the p-type semiconductor layer 16 is coaxial (center axis CZ) and similar in shape to the first region 14C of the n-type semiconductor layer 14, and has a central region 16C which is a convex portion of a triangular prism shape with each side parallel to each side of the first region 14C, and an outer region 16P which is a concave portion on the outer periphery of the central region 16C. The surface of the central region 16C is flat, and the central region 16C has a triangular prism shape with a step 16S height.

[0029] Therefore, the light-emitting structure layer EM, that is, the first region 14C of the n-type semiconductor layer 14, the active layer 15 formed on the first region 14C, and the p-type semiconductor layer 16, as a whole, constitute a triangular prism-shaped light confinement structure.

[0030] Regarding the central region 16C of the equilateral triangle shape, for example, an equilateral triangle with a side length of 12.5 μm can be exemplified, but it is not limited to this. It is preferable that the side length is between 3.5 μm and 20 μm.

[0031] The outer peripheral region 16P of the p-type semiconductor layer 16 has a high-resistance layer 16H on its surface that has higher electrical resistance than the central region 16C. That is, the central region 16C is a low-resistance region, and the surface layer of the outer peripheral region 16P is a high-resistance region. Therefore, the p-type semiconductor layer 16 functions as a current-constricting layer, and current is injected into the active layer 15 through the central region 16C. In other words, the surface-emitting laser 10 has a current-constricting structure in the shape of an equilateral triangle.

[0032] The high-resistance layer 16H is formed by dry etching the growth surface region of the p-type semiconductor layer 16 corresponding to the outer peripheral region 16P after the growth of the p-type semiconductor layer 16, thereby inactivating the p-type impurities in that region. Furthermore, a step 16S is formed by this dry etching.

[0033] The method for forming the high-resistance layer 16H is not limited to this. For example, after forming a step 16S on the growth surface of the p-type semiconductor layer 16, the surface layer of the outer peripheral region 16P may be made highly resistive by ion implantation or the like. Alternatively, after forming a step 16S on the growth surface of the p-type semiconductor layer 16, a high-resistance layer such as an insulating layer may be formed on the outer peripheral region 16P.

[0034] Furthermore, the surface layer of the central region 16C of the p-type semiconductor layer 16 may be formed as a highly doped p-contact layer with more p-type impurities than the lower layer.

[0035] A translucent conductive layer 18 is formed on the p-type semiconductor layer 16. The translucent conductive layer 18 has an uneven shape corresponding to the central region 16C and the outer peripheral region 16P of the p-type semiconductor layer 16, that is, an uneven shape that reflects the unevenness of the p-type semiconductor layer 16.

[0036] In other words, when viewed from above, the translucent conductive layer 18 has a central part that is coaxial with and similar in shape to the central region 16C of the p-type semiconductor layer 16, with each side being parallel to each side of the central region 16C, forming an equilateral triangle, and an outer recess of the central part.

[0037] Furthermore, it is preferable that the translucent conductive layer 18 has a certain thickness. The thickness of the translucent conductive layer 18 is preferably 100 nm or less, and more preferably 50 nm or less. This is because a large amount of current flows at the apex of the current-constricting structure (current injection region CA, described later). For example, a metal oxide such as indium tin oxide (ITO) can be used as the translucent conductive layer 18, but it is not limited to this.

[0038] A p-electrode 25 (second electrode) electrically connected to the translucent conductive layer 18 is provided on the outer periphery (recess) of the translucent conductive layer 18. As shown in Figure 2, in this embodiment, the p-electrode 25 has an annular shape, and a translucent spacer layer 19 is provided inside the p-electrode 25. The p-electrode 25 may also have a triangular or rectangular annular shape.

[0039] The spacer layer 19 has a circular shape when viewed from above. The spacer layer 19 has an uneven shape that reflects the unevenness of the central region 16C and the outer peripheral region 16P of the p-type semiconductor layer 16. It is preferable that the spacer layer 19 has a constant layer thickness. The spacer layer 19 functions as a phase adjustment layer. As the spacer layer 19, for example, niobium pentoxide (Nb ２ O ５ Examples of dielectric materials include, but are not limited to, those such as ).

[0040] A second reflector 21, which is a dielectric DBR, is formed on the spacer layer 19. The second reflector 21 is formed by alternately stacking two dielectric layers, each having an optical thickness of 1 / 4 wavelength and having different refractive indices. For example, the second reflector 21 is made of SiO ２ (11 layers) and Nb ２ O ５ It consists of 10.5 pairs of (10 layers). The second reflector 21 also has an uneven surface that reflects the uneven surface of the p-type semiconductor layer 16.

[0041] More specifically, as shown in FIGS. 1 and 2, the second mirror 21 has a step 21S in the shape of an equilateral triangle in a top view, and is coaxial (central axis CZ) with the central region 16C of the p-type semiconductor layer 16 and has a similar shape, and is a convex portion in the shape of an equilateral triangle with each side parallel to each side of the central region 16C, a central region 21C (central reflection region), and an outer peripheral region 21P (outer peripheral reflection region) which is the outer peripheral portion (recessed portion) of the central region 21C. Further, the second mirror 21 has a regular triangular prism shape in which each side surface is parallel to each side of the central region 16C of the p-type semiconductor layer 16. It is preferable that the central region 21C of the second mirror 21 is larger than the central region 16C of the p-type semiconductor layer 16 in a top view.

[0042] As described above, the light-emitting structure layer EM and the second mirror 21 are each configured as a columnar mesa having the central axis CZ as an axis. The light-emitting structure layer EM can be formed, for example, by laminating an n-type semiconductor layer 14, an active layer 15, and a p-type semiconductor layer 16 on the first mirror 13 and then etching these layers until reaching the p-type semiconductor layer 16. In addition, in a top view, the outer shapes of the light-emitting structure layer EM, the spacer layer 19, and the second mirror 21 may be an equilateral triangle or a rectangle.

[0043] Therefore, the surface-emitting laser 10 has an equilateral triangle-shaped current confinement structure and a lateral light confinement structure in the shape of a regular triangular prism that is coaxial and similar to the current confinement structure and has each side surface parallel to each side of the current confinement structure.

[0044] Further, the first mirror 13 and the second mirror 21 are arranged to face each other, and constitute a resonator in the shape of a regular triangular prism with the direction perpendicular to the light-emitting structure layer EM (the direction perpendicular to the substrate 11) as the resonator length direction.

[0045] By applying a voltage between the n electrode 23 and the p electrode 25, current is injected into the active layer 15, and light is emitted from the active layer 15. The light emitted from the active layer 15 is repeatedly reflected between the first mirror 13 and the second mirror 21, and laser oscillation occurs.

[0046] Figure 4 is a schematic cross-sectional view showing the resonator OC of the surface-emitting laser 10. Figure 4 is a cross-sectional view similar to that of Figure 1, but the hatching has been omitted. The resonator OC has a central region R1 corresponding to the central region 16C (low-resistance region) of the p-type semiconductor layer 16, and an outer region R2 corresponding to the outer region 16P (high-resistance region) of the p-type semiconductor layer 16.

[0047] In this embodiment, as described above (see Figure 3), the thickness of the central region 16C of the p-type semiconductor layer 16 is greater than the thickness of the outer region 16P of the p-type semiconductor layer 16. Also, the thickness of the other layers between the first reflector 13 and the second reflector 21 is constant.

[0048] Therefore, the effective refractive index n1 of the central region R1 of the resonator OC is greater than the effective refractive index n2 of the outer region R2. Also, the optical distance OL1 between the first reflector 13 and the second reflector 21 in the central region R1 is greater than the optical distance OL2 in the outer region R2. In other words, the effective resonator length in the central region R1 is longer than the effective resonator length in the outer region R2.

[0049] Furthermore, since the thickness of the p-type semiconductor layer 16 in the outer region R2 is smaller than the thickness in the central region R1, the effective resonance wavelength is shortened and the effective refractive index is reduced. Therefore, by making the thickness of the outer region 16P of the p-type semiconductor layer 16 smaller than the thickness of the central region 16C, light is effectively confined in the lateral direction.

[0050] Figure 5 is a plan view showing the current injection region CA (current injection aperture), i.e., the light-emitting regions E1, E2, and E3 within the central region 16C of the p-type semiconductor layer 16. When the surface-emitting laser 10 is driven, the light-emitting pattern has an equilateral triangular shape corresponding to the current injection region CA.

[0051] More specifically, the vertex region of the equilateral triangular current injection region CA (central region 16C) is the light-emitting region E1, the band-shaped rectangular region along the side between the two light-emitting regions E1 is the light-emitting region E2, and the central region of the current injection region CA inside the three light-emitting regions E2 is the light-emitting region E3.

[0052] (1) Light-emitting region of the current injection area

[0053] (a) Emitting region E1 The luminescent region E1, which is the top region of the current injection region CA, has one light-emitting point and the highest light intensity.

[0054] As described above, the effective refractive index in the outer region R2 of the resonator OC is smaller than the effective refractive index in the central region R1. Therefore, the optical emission loss is lowest in the apex region (emission region E1), where lateral optical confinement occurs from both directions of the two edges of the equilateral triangular current injection region CA. Consequently, oscillation occurs first in the apex region upon current injection, and even after oscillation, the light intensity of the emission point in the apex region is the greatest.

[0055] (b) Light-emitting region E2 In the light-emitting region E2, light confinement from the direction of one side of the current injection region CA is dominant. Therefore, as the injected current increases, oscillation occurs in the light-emitting region E2 following that in the light-emitting region E1. Depending on the size of the current injection region CA, oscillation occurs at multiple light-emitting points within the rectangular light-emitting region E2 along the side of the current injection region CA.

[0056] (c) Light-emitting region E3 Following the light emission in light-emitting region E2, oscillation occurs in light-emitting region E3.

[0057] In other words, the number of light-emitting points and the intensity of light emission within the current injection region CA change according to the injection current density, and at high injection currents, oscillation occurs at a large number of light-emitting points. Furthermore, oscillation occurs in phase at each light-emitting point located in the light-emitting regions E1 to E3. The light emission at these points is a longitudinal single mode with slightly different wavelengths, but it is emitted in phase. Therefore, the longitudinal mode of the surface-emitting laser 10 is multimode and oscillates at multiple wavelengths, but the transverse mode of the surface-emitting laser 10 maintains a unimodal single-mode operation from low to high injection currents.

[0058] Conventionally, for example, in blue and green VCSEL elements, obtaining transverse single-mode operation required, for instance, limiting the diameter of the circular current injection aperture to approximately 5.5 μm or less. Furthermore, conventional longitudinal single-mode VCSEL elements are prone to speckle problems due to the high coherence of the emitted beam.

[0059] The surface-emitting laser 10 has a current injection aperture with a larger area than conventional lasers, but transverse single-mode operation is maintained even with high injection currents. Therefore, a VCSEL element with low speckle noise and a high-power single-peak beam can be obtained.

[0060] For example, in the case of a current injection region CA with a triangular shape and sides of 12.5 μm, the area of ​​the current injection region CA is equal to the area of ​​a circular current injection region with a diameter of 9.2 μm. In this circular current injection region VCSEL element, transverse multimode (multi-peaked) operation is performed.

[0061] Furthermore, even in the case of a current injection region CA with an equilateral triangular shape and an inscribed circle of 5.5 μm or less, a high-power single-peaked beam laser light source can be obtained. In this case, higher-order modes that generate many optical fields outside the inscribed circle are less likely to exist, and a larger emission area than the area of ​​the inscribed circle is obtained, so a VCSEL element with a single peaked beam and higher power can be obtained than a VCSEL element that uses the inscribed circle as the current injection aperture.

[0062] (2) In the electrode-arranged surface-emitting laser 10, the n electrode 23 is provided on the second region 14P of the n-type semiconductor layer 14. In VCSEL elements made of nitride semiconductors such as blue light emission elements, the electrical resistance of the semiconductor layer is lower compared to VCSEL elements such as red light emission elements where the electrodes are provided on the back surface of the substrate, and the n electrode 23 is positioned on the outer side of the light-emitting structure layer EM.

[0063] Therefore, the proportion of current directed towards the outer periphery of the light-emitting structural layer EM is large, and the electric field strength is thought to be stronger in the outer periphery (aperture top and edges) compared to the central part of the current injection aperture (current injection region CA). Furthermore, the p electrode 25 and n electrode 23 are preferably annular in shape, so that the light-emitting region E1 is the region closest to the electrodes, oscillation is more likely to occur, and the current threshold is lowered. As a result, a VCSEL element with a low threshold current density, high output, and a single-peak beam can be obtained.

[0064] (3) Characterization Results The characteristics of the surface-emitting laser 10 were evaluated. Figure 6 is a graph showing the optical output-current characteristics (L-I characteristics) of the surface-emitting laser 10 in CW operation (@25°C). Figure 7 shows the near-field image FFP and far-field image FFP when the injection current I is 5 mA and 4 mA. Figure 8 shows the optical spectra when the injection current I is 5 mA and 4 mA.

[0065] As shown in the near-field FFP in Figure 7, oscillation was confirmed at three light-emitting points corresponding to the vertices of the equilateral triangle in the current injection region CA. In other words, it was confirmed that oscillation was occurring in longitudinal multimode (wavelength multimode oscillation). Furthermore, as shown in the far-field FFP in Figure 7 and the optical spectrum in Figure 8, it was confirmed that oscillation was occurring in transverse single mode.

[0066] As shown in Figure 8, a redshift was observed at I = 5 mA compared to the optical spectrum at I = 4 mA. This redshift is due to the heating and temperature rise of the resonator (the entire VCSEL), and is caused by the increase in current.

[0067] In the above-described embodiment, the light-emitting structure layer and the second reflector are configured as a cylindrical mesa waveguide structure, and the current injection region CA has an equilateral triangular shape. However, the shape of the waveguide structure and the current injection region are not limited to these. For example, the current injection region CA may have a triangular shape, or it may have an n-sided polygon shape (where n is an integer of 3 or more).

[0068] As described in detail above, the present disclosure provides a vertical-cavity surface-emitting laser made of a nitride semiconductor that maintains transverse single-mode operation from low to high injection currents and can obtain high optical output.

[0069] 10: Surface-emitting laser 11: Substrate 14: n-type semiconductor layer (first semiconductor layer) 14C: First region 14P: Second region 14S: Step 15: Active layer 16: p-type semiconductor layer 16C: Central region 16H: High-resistance layer 16P: Outer region 16S: Step 18: Translucent conductive layer 19: Spacer layer 21C: Central region 21P: Outer region 21S: Step 23: n-electrode 25: p-electrode CA: Current injection region CZ: Central axis

Claims

1. A vertical-cavity surface-emitting laser made of a nitride semiconductor, comprising: a substrate; a first multilayer mirror formed on the substrate; a first semiconductor layer of a first conductivity type formed on the first multilayer mirror and having a first region which is a central convex portion and a second region which is an outer recess of the first region when viewed from above; an active layer formed on the first region of the first semiconductor layer; a second semiconductor layer of a second conductivity type formed on the active layer and having a central region which is an n-sided convex portion (where n is an integer of 3 or more) and an outer recess of the central region when viewed from above; a translucent conductive layer formed on the central region of the second semiconductor layer; and a second multilayer mirror formed on the translucent conductive layer, wherein a high-resistance layer with higher resistance than the second semiconductor layer is provided on the surface of the outer region of the second semiconductor layer.

2. The vertical-cavity surface-emitting laser according to claim 1, wherein the second multilayer reflecting mirror is coaxial and similar in shape to the central region of the second semiconductor layer when viewed from above, has a step in the shape of an equilateral triangle with each side parallel to each side of the central region, and has a central reflecting region which is a central convex portion and an outer peripheral reflecting region which is an outer peripheral concave portion.

3. The vertical-cavity surface-emitting laser according to claim 1, wherein the first multilayer mirror is a semiconductor DBR and the second multilayer mirror is a dielectric DBR.

4. The vertical cavity type surface-emitting laser according to claim 1, wherein the thickness of the translucent conductive layer is 100 nm or less.

5. The vertical resonator type surface-emitting laser according to claim 1, having an annular first electrode provided on the second region of the first semiconductor layer and electrically connected to the first semiconductor layer.

6. The vertical resonator type surface-emitting laser according to claim 1, wherein the n-gon shape is triangular.

7. The vertical resonator type surface-emitting laser according to claim 1, wherein the first region of the first semiconductor layer has an equilateral triangular shape when viewed from above, with one side measuring 3.5 μm or more and 20 μm or less.

8. The vertical resonator type surface-emitting laser according to any one of claims 1 to 7, wherein the nitride semiconductor is a GaN-based semiconductor.

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