A photonic crystal semiconductor laser

Abstract

The present invention relates to the technical field of lasers, and particularly to a photonic crystal semiconductor laser, comprising: a pump cavity surrounded by a top sidewall, a bottom sidewall, and an annular sidewall, the top sidewall having a light output window, and the bottom sidewall being curved; a gain chip disposed at the light output window, the gain chip including a substrate, an active layer, a window layer, and a photonic crystal structure arranged in sequence in a direction away from the bottom sidewall, the photonic crystal structure having a plurality of holes; a mirror disposed on the surface of the bottom sidewall facing the pump cavity and facing the gain chip, the mirror being used to form a resonant cavity with the photonic crystal structure; and a plurality of pump units disposed on the surface of the bottom sidewall facing the pump cavity, and the plurality of pump units being arranged in an annular pattern around the mirror. The present invention is at least beneficial to reducing the manufacturing difficulty of the photonic crystal semiconductor laser and achieving a compact layout on the premise of realizing large-area and uniform carrier injection.

Description

Technical Field

[0001] The present invention belongs to the technical field of lasers, and in particular relates to a photonic crystal semiconductor laser. Background Art

[0002] Semiconductor lasers have the advantages of small volume, wide wavelength coverage range, easy integration, etc. Their gain chip structure can cover a relatively wide emission spectrum through semiconductor energy band design, and are widely used in fields such as laser medicine and industrial processing.

[0003] The photonic crystal surface-emitting semiconductor laser can perform mode selection on the output beam through the photonic crystal layer, and can achieve high beam quality and high-power laser output with a large emission area. However, due to the large emission area of the photonic crystal surface-emitting semiconductor laser, it is necessary to integrate a large-area electrode structure on the surface of the photonic crystal laser to improve the uniformity of current injection as much as possible. When integrating the electrode structure on the surface of the photonic crystal laser, it is necessary to grow a cladding layer to bury the photonic crystal layer, resulting in a relatively complex preparation process for the photonic crystal laser. Summary of the Invention

[0004] In view of this, the present invention aims to provide a photonic crystal semiconductor laser, which is at least beneficial to reducing the preparation difficulty of the photonic crystal semiconductor laser on the premise of achieving large-area and uniform carrier injection.

[0005] To achieve the above object, the technical solution of the present invention is realized as follows:

[0006] The present invention provides a photonic crystal semiconductor laser, comprising: a pump cavity surrounded by a top sidewall, a bottom sidewall, and an annular sidewall, the top sidewall and the bottom sidewall being oppositely arranged, the annular sidewall being located between the top sidewall and the bottom sidewall, the top sidewall having a light output window, and the bottom sidewall being curved; a gain chip disposed at the light output window, the gain chip including a substrate, an active layer, a window layer, and a photonic crystal structure arranged in sequence along a direction away from the bottom sidewall, the photonic crystal structure having a plurality of periodically arranged holes; a mirror disposed on the surface of the bottom sidewall facing the pump cavity and being directly opposite to the gain chip, the mirror being used to form a resonant cavity with the photonic crystal structure; and a plurality of pump units disposed on the surface of the bottom sidewall facing the pump cavity, and the plurality of pump units being annularly arranged on the outer periphery of the mirror, the plurality of pump units being used to emit pump light towards one end of the substrate of the gain chip.

[0007] Further, the photonic crystal semiconductor laser further comprises: a light-transmitting first heat dissipation structure at least located on the surface of the substrate away from the active layer, and the material of the first heat dissipation structure includes diamond or sapphire.

[0008] Further, an antireflection film is provided on the surface of the first heat dissipation structure away from the substrate.

[0009] Further, the photonic crystal semiconductor laser further includes: a light-transmissive second heat dissipation structure, the second heat dissipation structure is at least located on the surface of the photonic crystal structure away from the window layer, and the material of the second heat dissipation structure includes diamond or sapphire.

[0010] Further, an antireflection film is provided on the surface of the second heat dissipation structure away from the photonic crystal structure.

[0011] Further, the second heat dissipation structure is connected to the top sidewall, and the gain chip is disposed at the light-emitting window through the second heat dissipation structure.

[0012] Further, the top sidewall, the bottom sidewall, and the annular sidewall are an integrally formed structure, and the materials of the top sidewall, the bottom sidewall, and the annular sidewall are the same. The materials of the top sidewall, the bottom sidewall, and the annular sidewall all include high-purity copper.

[0013] Further, the plurality of holes include at least one of a circular hole, a rectangular hole, a triangular hole, or an irregular hole.

[0014] Further, the pumping unit is a surface-emitting semiconductor laser.

[0015] Compared with the prior art, the present invention can achieve the following beneficial effects: The pumping cavity of the photonic crystal semiconductor laser provided by the present invention integrates a plurality of pumping units, which is beneficial to improving the miniaturization and integration of the photonic crystal semiconductor laser, and optically pumps the side of the gain chip away from the photonic crystal structure, avoiding the problem that the photonic crystal structure blocks the pumping light and causes uneven carrier injection of the pumping light. Moreover, the gain chip does not include a distributed Bragg reflector structure, which also avoids the blocking of the pumping light by the distributed Bragg reflector structure. A resonant cavity is formed by using a mirror and the photonic crystal structure. The pumping cavity and the mirror can reflect the pumping light, so that the unabsorbed pumping light can be reflected multiple times to continuously pump the gain chip. Thus, by integrating the pumping units, not only can large-area, uniform, and high-energy carrier injection be achieved by optical pumping, but also integrating electrodes on the photonic crystal structure is avoided, which is beneficial to reducing the manufacturing process difficulty of the photonic crystal semiconductor laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 is a schematic structural diagram of the photonic crystal semiconductor laser according to the embodiment of the present invention;

[0018] Figure 2 This is a top view of some structures in the photonic crystal semiconductor laser according to the embodiments of the present invention. Detailed implementation manners

[0019] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention.

[0020] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0021] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0023] The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0024] Refer to Figure 1 and Figure 2, the present invention provides a photonic crystal semiconductor laser, comprising: a pump cavity 105, which is surrounded by a top sidewall, a bottom sidewall and an annular sidewall, the top sidewall and the bottom sidewall are oppositely arranged, the annular sidewall is located between the top sidewall and the bottom sidewall, the top sidewall has a light-emitting window, and the bottom sidewall is curved; a gain chip 102 disposed at the light-emitting window, the gain chip 102 includes a substrate, an active layer, a window layer and a photonic crystal structure 101 arranged in sequence along the direction away from the bottom sidewall, and the photonic crystal structure has a plurality of holes 104 arranged periodically; a mirror 107, which is disposed on the surface of the bottom sidewall facing the pump cavity 105 and is opposite to the gain chip 102, and the mirror 107 is used to form a resonant cavity with the photonic crystal structure 101; a plurality of pump units 106, which are disposed on the surface of the bottom sidewall facing the pump cavity 105, and the plurality of pump units 106 are arranged in an annular pattern around the periphery of the mirror 107, and the plurality of pump units 106 are arranged in a multi-layer annular staggered pattern to achieve uniform pumping, and the plurality of pump units 106 are used to emit pump light towards one end of the substrate of the gain chip 102.

[0025] The window layer can be used as a buffer layer. During the preparation process of the photonic crystal structure, when etching the holes 104, the window layer can prevent the process of etching the holes 104 from damaging the active layer.

[0026] It should be noted that the epitaxial structure of the gain chip 102 does not need to be doped, and the gain chip 102 can select a semiconductor gain material with corresponding components or other types of gain medium materials according to the usage scenario to achieve a wide wavelength coverage range.

[0027] In some embodiments, the pump unit 106 is a laser chip, and the laser chip can select a material system according to the required wavelength band of the pump light. For example, if the required pump light wavelength is in the range of 600nm to 1200nm, the laser chip can use a gallium arsenide material system; if the required pump light wavelength is in the range of 1300nm to 1700nm, the laser chip can select an indium phosphide material system.

[0028] The mirror 107 needs to be coated with a high-reflectivity reflective film covering the wide spectrum of the wavelength output range. The type and parameters of the mirror 107 can be adjusted according to the required output spot size, the output power of the beam and other performance requirements of the photonic crystal semiconductor laser. In some embodiments, the mirror 107 includes but is not limited to a plane mirror, a plano-concave mirror, a plano-convex mirror or an aspherical mirror, etc.

[0029] In some embodiments, the inner surface of the bottom sidewall facing the pump cavity 105 has a groove, and the mirror 107 is disposed in the groove.

[0030] Further, it further includes: a light-transmitting first heat dissipation structure 103, the first heat dissipation structure 103 is at least located on the surface of the substrate away from the active layer, and the material of the first heat dissipation structure 103 includes diamond or sapphire. In other embodiments, the first heat dissipation structure 103 may also adopt other light-transmitting high thermal conductivity materials. Bonding one side of the gain chip 102 to the first heat dissipation structure 103 can efficiently export the heat of the gain chip 102.

[0031] Further, the surface of the first heat dissipation structure 103 away from the substrate has an antireflection film. The antireflection film here is an antireflection film with a high transmittance to the pump light, which is beneficial to improving the efficiency of optical pumping of the gain chip 102 by multiple pump units 106.

[0032] Further, the photonic crystal semiconductor laser further includes: a light-transmitting second heat dissipation structure 108, the second heat dissipation structure 108 is at least located on the surface of the photonic crystal structure away from the window layer, and the material of the second heat dissipation structure 108 includes diamond or sapphire. In other embodiments, the second heat dissipation structure 108 may also adopt other light-transmitting high thermal conductivity materials. Bonding the other side of the gain chip 102 to the second heat dissipation structure 108 can efficiently export the heat of the gain chip 102. And bonding the photonic crystal structure 101 to the second heat dissipation structure 108 can achieve efficient heat export at the top of the laser, and at the same time achieve coverage of the photonic crystal structure 101, avoiding contamination of the holes 104 of the photonic crystal structure 101.

[0033] Further, the surface of the second heat dissipation structure 108 away from the photonic crystal structure has an antireflection film, and the antireflection film here is an antireflection film with a high transmittance to the emitted laser.

[0034] Further, the second heat dissipation structure 108 is connected to the top side wall, and the gain chip 102 is arranged at the light output window through the second heat dissipation structure 108. In this way, the top side wall can cool the second heat dissipation structure 108, which is beneficial to efficiently exporting the heat generated when the gain chip works.

[0035] In some embodiments, the first heat dissipation structure 103, the gain chip, and the second heat dissipation structure 108 are all arranged at the light output window. The side surface of the first heat dissipation structure 103 is connected to the side wall of the light output window and in surface-to-surface contact. The side surface of the second heat dissipation structure 108 is connected to the side wall of the light output window and in surface-to-surface contact. In this way, the top side wall can cool the second heat dissipation structure 108 and the first heat dissipation structure 103, which is beneficial to efficiently exporting the heat generated when the gain chip works.

[0036] In some examples, the thickness of the top side wall is not less than the sum of the thicknesses of the first heat dissipation structure, the second heat dissipation structure, and the gain chip.

[0037] Furthermore, the top sidewall, the bottom sidewall, and the annular sidewall are of an integrally formed structure, and the materials of the top sidewall, the bottom sidewall, and the annular sidewall are the same. The materials of the top sidewall, the bottom sidewall, and the annular sidewall all include high-purity copper. It can be understood that in other embodiments, the materials of the top sidewall, the bottom sidewall, and the annular sidewall can also be other highly thermally conductive metal materials.

[0038] In some embodiments, highly reflective films for the wavelength band of the pump light are vapor-deposited on the surfaces of the top sidewall facing the pump cavity 105, the bottom sidewall facing the pump cavity 105, and the annular sidewall facing the pump cavity 105. In this way, it is beneficial to ensure that the pump light not fully absorbed by the gain chip 102 can continue to pump the gain chip 102 after multiple reflections in the pump cavity 105, which is conducive to improving the pump efficiency.

[0039] Furthermore, the multiple holes 104 in the photonic crystal structure 101 include at least one of circular holes, rectangular holes, triangular holes, or irregular holes. In some examples, among the multiple holes 104 in the photonic crystal structure 101, holes of two shapes are arranged in a two-period pattern.

[0040] Specifically, the shape, size, and arrangement of the holes 104 of the photonic crystal structure 101 can be designed according to the parameter requirements of the photonic crystal semiconductor laser. The arrangement of the holes 104 in the photonic crystal structure 101 can be a single-period arrangement or a double-period arrangement.

[0041] In some embodiments, the thicknesses of the top sidewall, the bottom sidewall, and the annular sidewall are all in the range of 3 mm to 30 mm. The outer diameter of the annular sidewall can be in the range of 30 mm to 500 mm, the inner diameter of the annular sidewall can be in the range of 25 mm to 450 mm. The light-emitting window on the top sidewall is a square hole, and the side length of the square hole can be in the range of 0.5 mm to 50 mm. The groove for setting the mirror 107 on the surface of the bottom sidewall facing the pump cavity 105 can be a circular groove, and the diameter of the circular groove can be in the range of 1 mm to 100 mm.

[0042] In some embodiments, the mirror 107 can be a circular flat mirror. The diameter of the circular flat mirror can be in the range of 1 mm to 100 mm, the thickness of the circular flat mirror can be in the range of 0.5 mm to 50 mm, and the wavelength band corresponding to the highly reflective film coated on the circular flat mirror can be 800 nm to 1500 nm.

[0043] In some embodiments, the orthographic projection of the first heat dissipation structure 103 on the substrate surface is a square, the side length of the square can be in the range of 0.5 mm to 50 mm, the thickness of the first heat dissipation structure 103 can be in the range of 0.3 mm to 30 mm, and the wavelength range of the light beam corresponding to the antireflection film on the surface of the first heat dissipation structure 103 is 800 nm to 1500 nm.

[0044] In some embodiments, the orthographic projection of the second heat dissipation structure 108 on the substrate surface is a square, the side length of the square can be in the range of 0.5 mm to 50 mm, the thickness of the second heat dissipation structure 108 can be in the range of 0.3 mm to 30 mm, and the wavelength range of the light beam corresponding to the antireflection film on the surface of the second heat dissipation structure 108 is 800 nm to 1500 nm.

[0045] In some embodiments, the photonic crystal structure 101 includes a plurality of circular holes arranged in an array, the diameter of the circular holes can be in the range of 1 nm to 500 nm, the depth of the circular holes can be in the range of 10 nm to 1000 nm, and the duty cycle of the plurality of circular holes can be in the range of 5% to 50%.

[0046] In some embodiments, the gain chip 102 is a gain chip 102 of a gallium arsenide material system, the material of the substrate is GaAs, the gain chip 102 has no DBR (distributed Bragg reflector) structure, and the active layer includes a periodically arranged barrier layer / quantum well layer / barrier layer structure. The material of the barrier layer can be Al 0.06 GaAs, the material of the quantum well layer can be In 0.32 GaAs. In some other examples, the component of In in the quantum well layer can be in the range of 0 to 0.5, the component of Al can be in the range of 0 to 0.2, the thickness of the barrier layer can be in the range of 20 nm to 200 nm, the thickness of the quantum well layer can be in the range of 1 nm to 20 nm, and the emission wavelength band corresponding to the gain chip 102 is 800 nm to 1300 nm.

[0047] In some embodiments, the window layer is made of Al z GaAs material, where 0 < z < 1, and the thickness of the window layer can be in the range of 10 nm to 800 nm.

[0048] Furthermore, the pumping unit 106 is a surface-emitting semiconductor laser.

[0049] In some embodiments, the pumping unit 106 is a surface-emitting semiconductor laser based on a gallium arsenide material system. The surface-emitting semiconductor laser includes: a substrate, the material of the substrate is N-type GaAs; an N-type DBR layer, and the N-type DBR layer includes alternately arranged Al 0.25Ga 0.75 As layer and Al 0.95 Ga 0.05 As layer, the thickness of a single-layer material in the N-type DBR layer can be 1 / 4 of the output wavelength, the dopant of the N-type DBR layer can be Si, and the doping concentration of Si can be in the range of 1E16 / cm 3 ~8E18 / cm 3 ; the active region is a barrier layer / quantum well layer / barrier layer structure, the material of the barrier layer can be Al 0.42 Ga 0.58 As, the material of the quantum well layer can be Al 0.08 Ga 0.92 As, the thickness of the barrier layer can be in the range of 20nm - 200nm, the thickness of the quantum well layer can be in the range of 1nm - 20nm, and the emission wavelength band of the surface-emitting semiconductor laser can be 600nm - 800nm; P-type DBR layer, the P-type DBR layer includes Al 0.25 Ga 0.75 As and Al 0.95 Ga 0.05 As, the dopant of the P-type DBR layer can be C, and the doping concentration of C can be in the range of 1E18 / cm 3 ~1E20 / cm 3 ; oxidation confinement layer, the material of the oxidation confinement layer is Al 0.98 Ga 0.02 As, the thickness of the oxidation confinement layer can be in the range of 20nm - 1000nm.

[0050] It should be noted that multiple pump units 106 form a curved surface annular pump array, and the curved surface annular pump array is inclined inward to ensure that the light emitted by each pump unit 106 converges to the bottom of the gain chip 102. The curved surface annular pump array includes multiple layers of pump units arranged in a staggered manner. By coupling and superimposing the light beams emitted by the pump units through the multi-layer staggered arrangement, a large-area and uniform pump spot is achieved. The scaling of the pump power can be realized by increasing or decreasing the number of pump units 106 and the arrangement layers in the curved surface annular pump array. Also, according to the emission area and pump light power required by the photonic crystal semiconductor laser, the curvature radius and size of the bottom sidewall can be adjusted, and the pump area adjustment and pump power adjustment can be achieved by increasing or decreasing the number of pump units 106, the arrangement layers and the inclination angle in the curved surface annular pump array.

[0051] For the curved surface annular pump array formed by multiple pump units, in some examples, the pump unit is a surface-emitting semiconductor laser, and the light emitted by the surface-emitting semiconductor laser is a circular symmetric spot. Through the multi-layer staggered and annular arrangement of the pump units, it is ensured that the pump spots generated by multiple pump units are staggered and superimposed to form a uniform circular pump spot.

[0052] In some embodiments, the surface of the bottom sidewall facing the pumping cavity can be an ellipsoidal inner wall or a hemispherical inner wall. In some examples, the radius of curvature R of the hemispherical inner wall satisfies: 10 mm ≤ R ≤ 100 mm. In some examples, the radius of curvature R is preferably in the range of 20 mm to 50 mm. In this range, the compactness of the arrangement of the pumping units and the uniformity of the superposed light spots can be taken into account. In some examples, the opening diameter D of the hemispherical inner wall and the radius of curvature R satisfy: D = 2R×sin(α), where α is the half-angle of the opening of the hemispherical inner wall, and α is preferably in the range of 60° to 120°. In some examples, the hemispherical inner wall is coated with a high-reflection film with a reflectivity > 99% for the laser wavelength.

[0053] For the curved surface annular pumping array formed by multiple pumping units, in some embodiments, the multiple pumping units are arranged in a layered and staggered manner along the latitude direction from bottom to top; the number of layers N of the pumping units arranged in a ring in the curved surface annular pumping array is determined by the radius of curvature R of the hemispherical inner wall and the target spot size. In some examples, the number of layers N of the pumping units satisfies: N = [R / k], where k is the layer spacing adjustment coefficient, and k is in the range of 3 mm to 8 mm. In some examples, the number M of pumping units in each layer satisfies: M ≥ 2π×r n ×sin(θ / 2), r n is the radius of the nth layer ring, and θ is the divergence angle. For example, R = 30 mm, θ = 20°, the radius r2 of the second layer is 10 mm, and the second layer needs to include at least 12 pumping units; the staggered angle Δφ between adjacent pumping units in adjacent layers is 180° / M. In this way, it is beneficial to eliminate interference fringes.

[0054] In some examples, the basic parameters of the pumping unit are as follows: the wavelength is in the range of 750 nm to 1500 nm, preferably 808 nm or 940 nm, which can ensure coverage of the pumping requirements of mainstream semiconductor lasers and solid-state lasers; the single-point output power is in the range of 0.01 W to 100 W, and it can be in continuous or pulse mode. Preferably, the single-point output power is in the range of 0.1 W to 1 W. In this way, the thermal effect and the light intensity requirements can be balanced; the divergence angle (full angle) is in the range of 1° to 40°, preferably 5° to 30°. In this way, it matches the concave surface focusing characteristics; the pumping spot size D satisfies: θ ≥ 2×arcsin(D / 2R); the diameter of the pumping unit is in the range of 2 mm to 8 mm, preferably 3 mm to 5 mm. In this way, it is beneficial to ensure a relatively high uniformity of light field superposition while arranging closely; the beam mode is a near-Gaussian beam (beam quality evaluation factor M² ≤ 1.5).

[0055] In some examples, in order to improve the uniformity of the pump spot, the powers of the pump units located in different layers are designed as follows: the power of the outermost pump unit is 100%, and it decreases towards the inner layer, and the power difference between adjacent layers is in the range of 3% to 8%; and the distance between the pump units is greater than 1.2 times the diameter of the pump unit. In this way, it is beneficial to reduce thermal crosstalk; the installation angle error of the pump unit ≤ ±0.5°, and the axial position deviation ≤ ±0.2 mm.

[0056] The photonic crystal semiconductor laser provided by the above embodiment solves the problem that it is difficult to achieve large-area uniform carrier injection in a photonic crystal laser, and can achieve stable high-power laser output. Specifically, a gain chip 102 including a photonic crystal structure 101 without a DBR structure is used, combined with a curved annular pump array and a mirror 107 to achieve laser output. The gain chip 102 without a DBR structure realizes carrier injection by bottom optical pumping, avoiding the blockage of the pump light by the photonic crystal structure 101 and the DBR structure, and using the mirror 107 to reflect the laser generated by the gain chip 102 to the light output surface. The gain chip 102 is bonded between the first heat dissipation structure 103 and the second heat dissipation structure 108, and a pump cavity 105 is formed by using a high thermal conductivity metal material, which can effectively improve the heat dissipation of the photonic crystal semiconductor laser.

[0057] It should be understood that the various forms of the processes shown above can be used, steps can be reordered, added or deleted. For example, the steps recorded in the disclosure of the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in the present invention can be achieved, and no limitations are imposed herein.

[0058] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A photonic crystal semiconductor laser, characterized in that, Comprising: A pump cavity, which is surrounded by a top side wall, a bottom side wall and an annular side wall. The top side wall and the bottom side wall are oppositely arranged, the annular side wall is located between the top side wall and the bottom side wall, the top side wall has a light output window, and the bottom side wall is curved; A gain chip disposed at the light output window. The gain chip includes a substrate, an active layer, a window layer and a photonic crystal structure arranged in sequence in a direction away from the bottom side wall. The photonic crystal structure has a plurality of holes arranged periodically; A mirror, which is disposed on the surface of the bottom side wall facing the pump cavity and is opposite to the gain chip. The mirror is used to form a resonant cavity with the photonic crystal structure; A plurality of pump units, which are disposed on the surface of the bottom side wall facing the pump cavity, and the plurality of pump units are arranged annularly around the periphery of the mirror. The plurality of pump units are used to emit pump light towards one end of the substrate of the gain chip.

2. The photonic crystal semiconductor laser according to claim 1, characterized in that, The photonic crystal semiconductor laser further includes: a light-transmitting first heat dissipation structure, which is at least located on the surface of the substrate away from the active layer, and the material of the first heat dissipation structure includes diamond or sapphire.

3. The photonic crystal semiconductor laser according to claim 2, characterized in that, The surface of the first heat dissipation structure away from the substrate has an antireflection film.

4. The photonic crystal semiconductor laser according to claim 1, characterized in that, The photonic crystal semiconductor laser further includes: a light-transmitting second heat dissipation structure, which is at least located on the surface of the photonic crystal structure away from the window layer, and the material of the second heat dissipation structure includes diamond or sapphire.

5. The photonic crystal semiconductor laser according to claim 4, characterized in that, The surface of the second heat dissipation structure away from the photonic crystal structure has an antireflection film.

6. The photonic crystal semiconductor laser according to claim 4, characterized in that, The second heat dissipation structure is connected to the top side wall, and the gain chip is disposed at the light output window through the second heat dissipation structure.

7. The photonic crystal semiconductor laser according to claim 1, wherein The top side wall, the bottom side wall and the annular side wall are an integrally formed structure, and the materials of the top side wall, the bottom side wall and the annular side wall are the same. The materials of the top side wall, the bottom side wall and the annular side wall all include high-purity copper.

8. The photonic crystal semiconductor laser according to claim 1, characterized in that, The plurality of holes include at least one of circular holes, rectangular holes, triangular holes or irregular holes.

9. The photonic crystal semiconductor laser according to claim 1, characterized in that, The pump unit is a surface-emitting semiconductor laser.

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