Optically pumped semiconductor laser and method of manufacturing the same

Abstract

This invention provides an optically pumped semiconductor laser and its fabrication method. The optically pumped semiconductor laser includes a semiconductor gain chip, a first heat sink, and a second heat sink. The semiconductor gain chip includes an active layer, a first light-transmitting heat dissipation structure, a second light-transmitting heat dissipation structure, a first film system, and a second film system. The first and second light-transmitting heat dissipation structures are located on opposite sides of the active layer along a first direction. The first film system is located on the surface of a portion of the first light-transmitting heat dissipation structure facing away from the active layer. The second film system is located on the surface of a portion of the second light-transmitting heat dissipation structure facing away from the active layer. The first heat sink is located on the side of the first film system facing away from the active layer and is also located on the side of the first film system along a second direction. The second heat sink is located on the side of the second film system facing away from the active layer and is also located on the side of the second film system along a second direction.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and specifically to an optically pumped semiconductor laser and its fabrication method. Background Technology

[0002] Optically pumped semiconductor light-emitting devices are devices that generate stimulated emission by using a certain semiconductor material as the working substance. The working principle is as follows: through a certain optical pumping excitation method, population inversion of non-equilibrium charge carriers is achieved between the energy bands (conduction band and valence band) of the semiconductor material, or between the energy bands of the semiconductor material and the impurity (acceptor or donor) energy levels. When a large number of electrons and holes in the population inversion state recombine, stimulated emission is generated. Semiconductor light-emitting devices are widely used because of their small size and high light-to-light conversion efficiency.

[0003] Optically pumped external cavity surface-emitting semiconductor lasers (ECLS) are an important type of optically pumped semiconductor laser. By combining a semiconductor gain medium with an optical resonator, they overcome the limitations of the mode area of ​​traditional electrically pumped semiconductor lasers, enabling single-mode output with high output power and high beam quality. This represents a novel solution for achieving high-brightness lasers. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to enhance the power of optically pumped semiconductor lasers and increase the spectral tuning range, thereby providing an optically pumped semiconductor laser and its fabrication method.

[0005] This application provides an optically pumped semiconductor laser, including a semiconductor gain chip, a first heat sink, and a second heat sink; wherein, the semiconductor gain chip includes: an active layer, a first light-transmitting heat dissipation structure, a second light-transmitting heat dissipation structure, a first film system, and a second film system; the first light-transmitting heat dissipation structure is located on one side of the active layer along a first direction; the second light-transmitting heat dissipation structure is located on the other side of the active layer along the first direction; the first film system is located on a portion of the surface of the first light-transmitting heat dissipation structure facing away from the active layer; the second film system is located on a portion of the surface of the second light-transmitting heat dissipation structure facing away from the active layer; wherein, the first heat sink is located on the side of the first light-transmitting heat dissipation structure facing away from the active layer, and the first heat sink is located on the side of the first film system along a second direction; the second heat sink is located on the side of the second light-transmitting heat dissipation structure facing away from the active layer, and the second heat sink is located on the side of the second film system along the second direction; wherein, the first direction and the second direction are perpendicular.

[0006] Optionally, the thickness of the first light-transmitting heat dissipation structure in the first direction is greater than the thickness of the first film system in the first direction, and the thickness of the second light-transmitting heat dissipation structure in the first direction is greater than the thickness of the second film system in the first direction.

[0007] Optionally, the thickness of the first light-transmitting heat dissipation structure in the first direction is 500nm~10mm; the thickness of the second light-transmitting heat dissipation structure in the first direction is 500nm~10mm.

[0008] Optionally, the material of the first light-transmitting heat dissipation structure includes any one of diamond, silicon carbide, sapphire, and graphene; the material of the second light-transmitting heat dissipation structure includes any one of diamond, silicon carbide, sapphire, and graphene.

[0009] Optionally, the thermal conductivity of the first light-transmitting heat dissipation structure is greater than that of the first film system, and the thermal conductivity of the second light-transmitting heat dissipation structure is greater than that of the second film system.

[0010] Optionally, the first light-transmitting heat dissipation structure has an absorption rate of less than or equal to 20% in the gain wavelength range of the active layer; the second light-transmitting heat dissipation structure has an absorption rate of less than or equal to 20% in the gain wavelength range of the active layer.

[0011] Optionally, the semiconductor gain chip further includes: a first bonding layer located between the first heat sink and the first light-transmitting heat dissipation structure; and a second bonding layer located between the second heat sink and the second light-transmitting heat dissipation structure.

[0012] Optionally, the semiconductor gain chip further includes: a first semiconductor blocking layer located between the active layer and the second light-transmitting heat dissipation structure; and a second semiconductor blocking layer located between the active layer and the first light-transmitting heat dissipation structure.

[0013] Optionally, the thickness of the first semiconductor barrier layer in the first direction is 10 nm to 20 μm; the thickness of the second semiconductor barrier layer in the first direction is 10 nm to 20 μm.

[0014] Optionally, the first film system is a first antireflection film system, and the second film system is a second antireflection film system. The optically pumped semiconductor laser further includes a reflector and an output mirror. The reflector is located on the side of the second film system and the second heat sink away from the active layer and is spaced apart from the semiconductor gain chip and the second heat sink. The output mirror is located on the side of the first film system and the first heat sink away from the active layer and is spaced apart from the semiconductor gain chip and the first heat sink. A resonant cavity is formed between the reflector and the output mirror.

[0015] Optionally, the first film system is a first Bragg reflector, the second film system is a second Bragg reflector, the reflectivity of the second Bragg reflector is greater than that of the first Bragg reflector, and the second film system and the first film system form a resonant cavity.

[0016] Optionally, the first film system is an antireflective film system, and the second film system is a reflective film system; wherein, the optically pumped semiconductor laser further includes: an output mirror, located on the side of the first film system and the first heat sink away from the active layer and spaced apart from the semiconductor gain chip and the first heat sink; the second film system and the output mirror form a resonant cavity.

[0017] This application also provides a method for fabricating an optically pumped semiconductor laser, including forming a semiconductor gain chip; forming the semiconductor gain chip includes: forming an active layer on one side of a substrate along a first direction; disposing a first light-transmitting heat dissipation structure on the side of the active layer away from the substrate, and then removing the substrate; after removing the substrate, disposing a second light-transmitting heat dissipation structure on the side of the active layer away from the first light-transmitting heat dissipation structure; forming a first film system on a portion of the surface of the first light-transmitting heat dissipation structure away from the active layer; forming a second film system on a portion of the surface of the second light-transmitting heat dissipation structure away from the active layer; the method for fabricating the optically pumped semiconductor laser further includes: bonding a first heat sink to the side of the first light-transmitting heat dissipation structure away from the active layer, the first heat sink being located on the side of the first film system along a second direction; bonding a second heat sink to the side of the second light-transmitting heat dissipation structure away from the active layer, the second heat sink being located on the side of the second film system along the second direction; wherein, the first direction is perpendicular to the second direction.

[0018] Optionally, forming a semiconductor gain chip further includes: forming a first semiconductor barrier layer on one side of the substrate along the first direction; wherein forming an active layer includes: forming the active layer on the side of the first semiconductor barrier layer away from the substrate; wherein removing the substrate includes: removing the substrate using the first semiconductor barrier layer as an etch stop layer; wherein disposing the second light-transmitting heat dissipation structure on the side of the active layer away from the first light-transmitting heat dissipation structure includes: disposing the second light-transmitting heat dissipation structure on the surface of the first semiconductor barrier layer away from the active layer.

[0019] Optionally, forming a semiconductor gain chip further includes: forming a second semiconductor barrier layer on the side of the active layer away from the first semiconductor barrier layer; wherein, disposing the first light-transmitting heat dissipation structure on the side of the active layer away from the substrate includes: disposing the first light-transmitting heat dissipation structure on the surface of the second semiconductor barrier layer away from the active layer.

[0020] Optionally, forming a semiconductor gain chip further includes: forming a first bonding layer on a portion of the first light-transmitting heat dissipation structure on the side facing away from the active layer; forming a second bonding layer on a portion of the second light-transmitting heat dissipation structure on the side facing away from the active layer; wherein, after forming the first film system, the first bonding layer surrounds the sidewall of the first film system; after forming the second film system, the second bonding layer surrounds the sidewall of the second film system; wherein, bonding the first heat sink to the side of the portion of the first light-transmitting heat dissipation structure facing away from the active layer includes: bonding the first heat sink to the side of the first bonding layer facing away from the first light-transmitting heat dissipation structure; wherein, bonding the second heat sink to the side of the portion of the second light-transmitting heat dissipation structure facing away from the active layer includes: bonding the second heat sink to the side of the second bonding layer facing away from the second light-transmitting heat dissipation structure.

[0021] Optionally, the first film system is a first antireflection film system, and the second film system is a second antireflection film system; wherein, the fabrication method of the optically pumped semiconductor laser further includes: disposing a reflector on the side of the second film system and the second heat sink away from the active layer and spaced apart from the semiconductor gain chip and the second heat sink; disposing an output mirror on the side of the first film system and the first heat sink away from the active layer and spaced apart from the semiconductor gain chip and the first heat sink; a resonant cavity is formed between the reflector and the output mirror.

[0022] Optionally, the first film system is a first Bragg reflector, the second film system is a second Bragg reflector, the reflectivity of the second Bragg reflector is greater than that of the first Bragg reflector, and the second film system and the first film system form a resonant cavity.

[0023] Optionally, the first film system is an antireflective film system, and the second film system is a reflective film system; wherein, the fabrication method of the optically pumped semiconductor laser further includes: disposing an output mirror on the side of the first film system and the first heat sink away from the active layer and spaced apart from the semiconductor gain chip and the first heat sink; a resonant cavity is formed between the second film system and the output mirror.

[0024] The technical solution of this invention has the following beneficial effects:

[0025] The optically pumped semiconductor laser provided by this invention has a first and a second transparent heat dissipation structure respectively disposed on both sides of the active layer along a first direction. The increased spacing between the first and second film systems in the first direction reduces the longitudinal mode spacing, i.e., the wavelength difference between adjacent longitudinal modes decreases. This suppresses the Fabry-Perot interference filtering effect between the first and second film systems, reducing the spectral modulation and filtering effect of this effect on the gain of the active layer. More longitudinal modes are allowed to be output within the gain wavelength range of the active layer, thereby increasing the gain spectral tuning range and facilitating wide-range wavelength tuning. Secondly, since the waste heat of the active layer is directly transferred to the first heat sink through the first transparent heat dissipation structure and directly transferred to the second heat sink through the second transparent heat dissipation structure, and the first and second transparent heat dissipation structures have high thermal conductivity and employ a double-sided heat dissipation method with a larger heat dissipation area, the heat dissipation capability of the active layer is enhanced, which is beneficial for heat extraction from the active layer and improves the output power of the optically pumped semiconductor laser.

[0026] In addition, the waste heat of the active layer can be transferred without relying on the first and second membrane systems. Therefore, the restrictions on the size of the first and second membrane systems in the first direction are reduced. The size of the first and second membrane systems in the first direction can be selected according to the design requirements. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of an optically pumped semiconductor laser according to an embodiment of this application;

[0029] Figure 2 This is a schematic diagram of an optically pumped semiconductor laser according to another embodiment of this application;

[0030] Figure 3 for Figure 2 A schematic diagram showing the change in reflectivity versus wavelength for the first film system in the diagram;

[0031] Figure 4 This is a schematic diagram of an optically pumped semiconductor laser according to another embodiment of this application;

[0032] Figure 5 for Figure 4 and Figure 6 A schematic diagram showing the change in reflectivity and wavelength of the second film system in the diagram;

[0033] Figure 6 This is a schematic diagram of an optically pumped semiconductor laser according to another embodiment of this application;

[0034] Figure 7 This is a schematic diagram showing the formation of a first semiconductor barrier layer, an active layer, and a second semiconductor barrier layer on one side of the substrate along a first direction.

[0035] Figure 8 This is a schematic diagram showing the first light-transmitting heat dissipation structure positioned on the side of the active layer away from the substrate.

[0036] Figure 9 In order to be in Figure 8 A schematic diagram after removing the substrate;

[0037] Figure 10 This is a schematic diagram showing the second light-transmitting heat dissipation structure positioned on the side of the active layer away from the first light-transmitting heat dissipation structure.

[0038] Figure 11 In order to be in Figure 10 A schematic diagram showing the formation of the first and second bonding layers on the foundation.

[0039] Figure 12 for Figure 11 A bottom view;

[0040] Figure 13 for Figure 11 Top view;

[0041] Figure 14 In order to be in Figure 11 A schematic diagram showing the formation of the first and second membrane systems based on this.

[0042] Figure 15 This is a schematic diagram showing the bonding of a first heat sink to the side of a portion of the first light-transmitting heat dissipation structure facing away from the active layer, and the bonding of a second heat sink to the side of a portion of the second light-transmitting heat dissipation structure facing away from the active layer. Detailed Implementation

[0043] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0045] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0046] Figure 1 This is a schematic diagram of an optically pumped semiconductor laser according to an embodiment of this application. Figure 2 This is a schematic diagram of an optically pumped semiconductor laser according to another embodiment of this application. Figure 4 This is a schematic diagram of an optically pumped semiconductor laser according to another embodiment of this application. Figure 6 This is a schematic diagram of an optically pumped semiconductor laser according to another embodiment of this application. (See reference) Figure 1 , Figure 2 , Figure 4 and Figure 6 The optically pumped semiconductor laser includes a semiconductor gain chip W, a first heat sink 100, and a second heat sink 190. The semiconductor gain chip includes an active layer 150, a first light-transmitting heat dissipation structure 130, a second light-transmitting heat dissipation structure 170, a first film system 120, and a second film system 200.

[0047] The first light-transmitting heat dissipation structure 130 is located on one side of the active layer 150 along the first direction Z; the second light-transmitting heat dissipation structure 170 is located on the other side of the active layer 150 along the first direction Z. The first film system 120 is located on the surface of a portion of the first light-transmitting heat dissipation structure 130 facing away from the active layer 150; the second film system 200 is located on the surface of a portion of the second light-transmitting heat dissipation structure 170 facing away from the active layer 150.

[0048] The first heat sink 100 is located on the side of a portion of the first light-transmitting heat dissipation structure 130 away from the active layer 150, and the first heat sink 100 is located on the side of the first membrane system 120 along the second direction X; the second heat sink 190 is located on the side of a portion of the second light-transmitting heat dissipation structure 170 away from the active layer 150, and the second heat sink 190 is located on the side of the second membrane system 200 along the second direction X.

[0049] Among them, the first direction Z and the second direction X are perpendicular.

[0050] In this embodiment of the optically pumped semiconductor laser, a first light-transmitting heat dissipation structure 130 and a second light-transmitting heat dissipation structure 170 are respectively provided on both sides of the active layer 150 along the first direction Z. The distance between the first film system 120 and the second film system 200 in the first direction Z is increased, and the longitudinal mode distance is decreased, that is, the wavelength difference between adjacent longitudinal modes is reduced. The Fabry-Perot interference filtering effect between the first film system 120 and the second film system 200 is suppressed, thereby suppressing the spectral modulation and filtering effect of this effect on the gain of the active layer 150. This allows for more longitudinal mode output within the gain wavelength range of the active layer 150, thus increasing the gain spectral tuning range and facilitating wide-range wavelength tuning. Secondly, since the waste heat of the active layer 150 is directly transferred to the first heat sink 100 through the first transparent heat dissipation structure 130 and directly transferred to the second heat sink 190 through the second transparent heat dissipation structure 170, the first transparent heat dissipation structure 130 and the second transparent heat dissipation structure 170 have high thermal conductivity and adopt a double-sided heat dissipation method with a larger heat dissipation area. Therefore, the heat dissipation capability of the active layer 150 is enhanced, which is beneficial for heat extraction from the active layer 150 and improves the output power of the optically pumped semiconductor laser.

[0051] In addition, the waste heat of the active layer 150 can be transferred independently of the first membrane system 120 and the second membrane system 200. Therefore, the restrictions on the size of the first membrane system 120 and the second membrane system 200 in the first direction Z are reduced. The size of the first membrane system 120 in the first direction Z can be selected according to the design requirements, and the size of the second membrane system 200 in the first direction Z can be selected according to the design requirements.

[0052] In one embodiment, reference Figure 2The first antireflection film system 120 is specifically designed for the output wavelength of the optically pumped semiconductor laser. The second antireflection film system 200 is also specifically designed for the output wavelength of the optically pumped semiconductor laser. The optically pumped semiconductor laser further includes a reflector 301 and an output mirror 400. The reflector 301 is located on the side of the second film system 200 and the second heat sink 190 away from the active layer 150 and is spaced apart from the semiconductor gain chip W and the second heat sink 190. The output mirror 400 is located on the side of the first film system 120 and the first heat sink 100 away from the active layer 150 and is spaced apart from the semiconductor gain chip W and the first heat sink 100. A resonant cavity is formed between the reflector 301 and the output mirror 400. The reflector 301 and the output mirror 400 are located on opposite sides of the semiconductor gain chip W in the first direction Z. The reflectivity of mirror 301 is greater than that of output mirror 400, and the laser is emitted from output mirror 400. In this case, the optically pumped semiconductor laser is an optically pumped external cavity surface-emitting semiconductor laser.

[0053] When the first film system 120 is the first antireflection film system and the second film system 200 is the second antireflection film system, the reflectivity of the first film system 120 to the gain wavelength of the active layer 150 and the reflectivity of the second film system 200 to the gain wavelength of the active layer 150 are both relatively small. This further suppresses the Fabry-Perot interference filtering effect and parasitic oscillations of the composite microcavity between the first film system 120 and the second film system 200, thereby further increasing the gain spectrum tuning range and achieving a wider range of wavelength tuning.

[0054] In one embodiment, when the first film system 120 is a first antireflection film system and the second film system 200 is a second antireflection film system, the reflectivity of the first film system 120 at the center wavelength of the light emitted from the optically pumped semiconductor laser is less than or equal to 0.2%, and the reflectivity of the second film system 200 at the center wavelength of the light emitted from the optically pumped semiconductor laser is less than or equal to 0.2%.

[0055] refer to Figure 3 , Figure 3 for Figure 2 The diagram shows the change in reflectance of the first film system 120 with wavelength, which also represents the change in reflectance of the second film system 200 with wavelength. The reflectance of the first film system 120 to light with a wavelength of 980nm is less than or equal to 0.2%, and the reflectance of the second film system 200 to light with a wavelength of 980nm is less than or equal to 0.2%.

[0056] When the first film system 120 is a first antireflection film system and the second film system 200 is a second antireflection film system, the thickness of the first film system 120 in the first direction Z can be made smaller, and the thickness of the second film system 200 in the first direction Z can be made smaller. For example, the thickness of the first film system 120 in the first direction Z is 150nm~600nm, such as 150nm, 200nm, 300nm, 400nm, 500nm or 600nm; the thickness of the second film system 200 in the first direction Z is 150nm~600nm, such as 150nm, 200nm, 300nm, 400nm, 500nm or 600nm.

[0057] Figure 2 The semiconductor gain chip W is provided with external optical excitation by pump light 500 in an oblique incidence manner. The reflector 301 has high reflectivity (e.g., reflectivity > 90%) for the laser emitted by the semiconductor gain chip W, and the output mirror 400 has partial transmission characteristics (e.g., transmittance 0.5%~10%) for the laser emitted by the semiconductor gain chip W. A resonant cavity is formed between the output mirror 400 and the reflector 301. The laser is amplified by stimulated emission in the resonant cavity and then output through the output mirror 400.

[0058] It should be noted that in existing technologies, during the fabrication of optically pumped external cavity surface-emitting semiconductor lasers (ECSLS), a bottom Bragg mirror and an active layer are sequentially grown on a substrate, with the bottom Bragg mirror being made of semiconductor material. During the growth of the active layer, lattice matching between the active layer material and the semiconductor Bragg mirror material is required; otherwise, the active layer will not emit light or will exhibit poor performance, thus presenting complex process requirements. Secondly, in existing technologies, the semiconductor-air interface at the top of the epitaxial wafer and the bottom Bragg mirror of the ECSLS form a Fabry-Perot microcavity, introducing a Fabry-Perot interference filtering effect. This effect modulates and filters the intrinsic material gain of the active layer, leading to a narrowing of the gain spectrum and making it difficult to achieve wide-range wavelength tuning. Furthermore, during operation, the active layer generates a significant amount of waste heat. Since the active layer is located above the bottom Bragg mirror, and the thicker bottom Bragg mirror increases the length of the heat dissipation channel, it is detrimental to heat extraction and power enhancement of the active layer. In contrast, the optically pumped external cavity surface-emitting semiconductor laser of this application can improve the above-mentioned problems.

[0059] The optically pumped external cavity surface-emitting semiconductor laser of this application can be applied to fields such as laser display, laser medicine, and laser detection.

[0060] The optically pumped external cavity surface-emitting semiconductor laser of this application has wavelength tuning freedom in the tens or even hundreds of nanometer range. For example, the wavelength tuning range of the output wavelength of the optically pumped external cavity surface-emitting semiconductor laser is 20 nm to 40 nm.

[0061] In another embodiment, reference Figure 6 The first film system 120 is a first Bragg reflector, and the second film system 200 is a second Bragg reflector. The reflectivity of the second Bragg reflector is greater than that of the first Bragg reflector. The second film system 200 and the first film system 120 form a resonant cavity. Due to the provision of the first light-transmitting heat dissipation structure 130 and the second light-transmitting heat dissipation structure 170, the spacing between the first film system 120 and the second film system 200 in the first direction Z is increased, suppressing the Fabry-Perot interference filtering effect between the first film system 120 and the second film system 200. This suppresses the spectral modulation and filtering effect of this effect on the gain of the active layer 150, thereby increasing the gain spectral tuning range and achieving wide-range wavelength tuning. The laser is emitted from the first film system 120.

[0062] In another embodiment, reference Figure 4 The first film system 120 is an antireflective film system, and the second film system 200 is a reflective film system. The optically pumped semiconductor laser also includes an output mirror 400, which is located on the side of the first film system 120 and the first heat sink 100 opposite to the active layer 150 and is spaced apart from the semiconductor gain chip W and the first heat sink 100. A resonant cavity is formed between the second film system 200 and the output mirror 400. The reflectivity of the second film system 200 is greater than that of the output mirror 400. The laser beam exits from the output mirror 400.

[0063] In one embodiment, when the first film system 120 is a first antireflection film system, the reflectivity of the first film system 120 at the center wavelength of the light emitted from the optically pumped semiconductor laser is less than or equal to 0.2%.

[0064] When the first film system 120 is the first antireflection film system, the thickness of the first film system 120 in the first direction Z can be made smaller. For example, the thickness of the first film system 120 in the first direction Z is 150nm~600nm, such as 150nm, 200nm, 300nm, 400nm, 500nm or 600nm.

[0065] refer to Figure 5 , Figure 5 for Figure 4 and Figure 6The diagram shows the change in reflectivity and wavelength of the second film system 200. The second film system 200 has a high reflectivity (e.g., reflectivity > 90%) for the laser light (980nm wavelength) emitted by the semiconductor gain chip W, for example, a reflectivity of 99%.

[0066] refer to Figure 4 The first film system 120 has a reflectivity of less than or equal to 0.2% for the laser emitted by the semiconductor gain chip W (light with a wavelength of 980nm). The output mirror 400 has partial transmittance characteristics for the laser emitted by the semiconductor gain chip W (e.g., transmittance of 0.5%~10%). External optical excitation for the semiconductor gain chip W is provided by a pump light 500. A resonant cavity is formed between the first film system 120 and the output mirror 400. The laser light is amplified by stimulated emission within the resonant cavity and then output through the output mirror 400.

[0067] refer to Figure 6 The first film system 120 has partial transmittance characteristics (e.g., transmittance of 0.5%~10%) for the laser light (980nm wavelength) emitted by the semiconductor gain chip W. A resonant cavity is formed between the first film system 120 and the second film system 200. The laser light is amplified by stimulated emission within the resonant cavity and then output through the first film system 120.

[0068] In one embodiment, reference Figure 1 , Figure 2 , Figure 4 and Figure 6 The thickness of the first light-transmitting heat dissipation structure 130 in the first direction Z is greater than the thickness of the first film system 120 in the first direction Z, and the thickness of the second light-transmitting heat dissipation structure 170 in the first direction Z is greater than the thickness of the second film system 200 in the first direction Z. That is, the larger thickness of the first light-transmitting heat dissipation structure 130 and the second light-transmitting heat dissipation structure 170 in the first direction Z further enhances the spacing between the first film system 120 and the second film system 200, further reduces the spectral modulation and filtering effect of this effect on the gain of the active layer 150, further increases the gain spectral tuning range, and further achieves wide-range wavelength tuning.

[0069] In one embodiment, the thickness of the first light-transmitting heat dissipation structure 130 in the first direction Z is 500nm~10mm, for example 0.8mm~1mm; the thickness of the second light-transmitting heat dissipation structure 170 in the first direction Z is 500nm~10mm, for example 0.8mm~1mm.

[0070] In one embodiment, the thermal conductivity of the first light-transmitting heat dissipation structure 130 is greater than that of the first film system 120, and the thermal conductivity of the second light-transmitting heat dissipation structure 170 is greater than that of the second film system 200. The higher thermal conductivity of the first light-transmitting heat dissipation structure 130 and the second light-transmitting heat dissipation structure 170 facilitates heat dissipation of the active layer 150. Heat dissipation can be achieved independently of the first film system 120 and the second film system 200, reducing the dimensional limitations of the first film system 120 and the second film system 200 in the first direction Z.

[0071] In one embodiment, the absorptivity of the first light-transmitting heat dissipation structure 130 in the gain wavelength range of the active layer 150 is less than or equal to 20%, for example, the absorptivity of the first light-transmitting heat dissipation structure 130 in the gain wavelength range of the active layer 150 is 20%, 15%, 10%, or 5%; the absorptivity of the second light-transmitting heat dissipation structure 170 in the gain wavelength range of the active layer 150 is less than or equal to 20%, for example, the absorptivity of the second light-transmitting heat dissipation structure 170 in the gain wavelength range of the active layer 150 is 20%, 15%, 10%, or 5%. The lower absorptivity of both the first and second light-transmitting heat dissipation structures reduces optical loss.

[0072] In one embodiment, the material of the first light-transmitting heat dissipation structure 130 includes any one of diamond, silicon carbide, sapphire, and graphene; the material of the second light-transmitting heat dissipation structure 170 includes any one of diamond, silicon carbide, sapphire, and graphene. The selection of these materials for both the first and second light-transmitting heat dissipation structures 130 and 170 facilitates heat dissipation from the active layer 150. Furthermore, the selection of these materials also results in lower absorptivity for both structures, reducing optical losses.

[0073] In one embodiment, the semiconductor gain chip W further includes a first bonding layer 110 and a second bonding layer 180, wherein the first bonding layer 110 is located between the first heat sink 100 and the first light-transmitting heat dissipation structure 130, and the second bonding layer 180 is located between the second heat sink 190 and the second light-transmitting heat dissipation structure 170.

[0074] In one embodiment, the material of the first bonding layer 110 may be titanium, platinum, gold, indium, gold-tin, or their compounds. The material of the second bonding layer 180 may be titanium, platinum, gold, indium, gold-tin, or their compounds.

[0075] In one embodiment, the semiconductor gain chip W further includes a first semiconductor blocking layer 160 and a second semiconductor blocking layer 140, wherein the first semiconductor blocking layer 160 is located between the active layer 150 and the second light-transmitting heat dissipation structure 170, and the second semiconductor blocking layer 140 is located between the active layer 150 and the first light-transmitting heat dissipation structure 130.

[0076] The materials of the first semiconductor barrier layer 160 and the active layer 150 are different, and the materials of the first semiconductor barrier layer 160 and the active layer 150 have different etching selectivity ratios. Furthermore, the materials of the first semiconductor barrier layer 160 and the second light-transmitting heat dissipation structure 170 are different. The first semiconductor barrier layer 160 is used to protect the active layer 150.

[0077] The material of the second semiconductor barrier layer 140 is different from that of the active layer 150, and the materials of the second semiconductor barrier layer 140 and the active layer 150 have different etching selectivity ratios. Furthermore, the material of the second semiconductor barrier layer 140 is different from that of the first light-transmitting heat dissipation structure 130. The second semiconductor barrier layer 140 is used to protect the active layer 150.

[0078] In one embodiment, the material of the first semiconductor barrier layer 160 includes InGaP, AlGaAs, or Si. The material of the second semiconductor barrier layer 140 includes InGaP, AlGaAs, or Si.

[0079] In one embodiment, the thickness of the first semiconductor barrier layer 160 in the first direction Z is 10nm~20μm, for example 40nm~60nm; the thickness of the second semiconductor barrier layer 140 in the first direction Z is 10nm~20μm, for example 40nm~60nm. The significance of choosing this range is that when the first semiconductor barrier layer 160 and the second semiconductor barrier layer 140 are both thicker, it is not conducive to further improving the heat conduction of the active layer 150, thereby limiting the further improvement of the output power; when the first semiconductor barrier layer 160 and the second semiconductor barrier layer 140 are both thinner, the protection effect on the active layer 150 is weaker.

[0080] In one embodiment, the active layer 150 includes one or more active units, which include a plurality of quantum well layers and barrier layers alternately stacked in the first direction Z.

[0081] In one embodiment, the quantum well layer is made of InGaAs, and the barrier layer is made of GaAs.

[0082] In one embodiment, the material of the first heat sink 100 can be a metal heat sink, such as copper; the first heat sink can also be a thermoelectric cooler.

[0083] In one embodiment, the material of the second heat sink 190 can be a metal heat sink, such as copper; the first heat sink can also be a thermoelectric cooler.

[0084] In one embodiment, the first film system 120 includes a first film and a second film stacked alternately in a first direction (Z-alternating), wherein the refractive index of the first film is greater than that of the second film. The second film system 200 includes a third film and a fourth film stacked alternately in the first direction (Z-alternating), wherein the refractive index of the third film is greater than that of the fourth film.

[0085] In one embodiment, the first membrane system 120 is a first dielectric membrane system, for example, the material of the first membrane is Ta2O5 and the material of the second membrane is SiO2. The second membrane system 200 is a second dielectric membrane system, for example, the material of the third membrane is Ta2O5 and the material of the fourth membrane is SiO2.

[0086] Since the first membrane system 120 and the second membrane system 200 are made of dielectric materials, they are easy to manufacture and the cost is reduced.

[0087] In another embodiment, the materials of the first film, the second film, the third film, and the fourth film can be semiconductor materials.

[0088] In one embodiment, the output center wavelength of the optically pumped semiconductor laser is 980 nm or 1030 nm. In other embodiments, the output center wavelength of the optically pumped semiconductor laser is not limited.

[0089] Another embodiment of this application provides a method for fabricating an optically pumped semiconductor laser, including forming a semiconductor gain chip: wherein forming the semiconductor gain chip includes: forming an active layer on one side of a substrate along a first direction; disposing a first light-transmitting heat dissipation structure on the side of the active layer away from the substrate, and then removing the substrate; after removing the substrate, disposing a second light-transmitting heat dissipation structure on the side of the active layer away from the first light-transmitting heat dissipation structure; forming a first film system on a portion of the first light-transmitting heat dissipation structure away from the active layer; forming a second film system on a portion of the surface of the second light-transmitting heat dissipation structure away from the active layer; the method for fabricating the optically pumped semiconductor laser further includes: bonding a first heat sink to the side of the first light-transmitting heat dissipation structure away from the active layer, the first heat sink being located on the side of the first film system along a second direction; bonding a second heat sink to the side of the second light-transmitting heat dissipation structure away from the active layer, the second heat sink being located on the side of the second film system along the second direction; wherein the first direction is perpendicular to the second direction.

[0090] The fabrication method of the optically pumped semiconductor laser in this embodiment involves placing a first light-transmitting heat dissipation structure on the side of the active layer away from the substrate. After removing the substrate, a second light-transmitting heat dissipation structure is placed on the side of the active layer away from the first light-transmitting heat dissipation structure. That is, the first and second light-transmitting heat dissipation structures are respectively placed on both sides of the active layer along a first direction. This increases the spacing between the first and second film systems in the first direction and decreases the longitudinal mode spacing, i.e., reduces the wavelength difference between adjacent longitudinal modes. This suppresses the Fabry-Perot interference filtering effect between the first and second film systems and inhibits the effect of this effect on the active layer. The spectral modulation and filtering effects generated by the gain of the active layer allow for more longitudinal mode outputs within the gain wavelength range of the active layer, thereby increasing the gain spectral tuning range and facilitating wide-range wavelength tuning. Secondly, since the waste heat of the active layer is directly transferred to the first heat sink through the first transparent heat dissipation structure and directly transferred to the second heat sink through the second transparent heat dissipation structure, the first and second transparent heat dissipation structures have high thermal conductivity and adopt a double-sided heat dissipation method with a larger heat dissipation area. Therefore, the heat dissipation capability of the active layer is enhanced, which is conducive to heat extraction from the active layer and improves the output power of the optically pumped semiconductor laser.

[0091] In existing technologies, the fabrication of optically pumped external cavity surface-emitting semiconductor lasers involves sequentially growing a bottom Bragg mirror and an active layer on a substrate. During the growth of the active layer, lattice matching between the active layer material and the semiconductor Bragg mirror material is crucial; otherwise, the active layer will fail to emit light or exhibit poor performance, thus requiring complex processing techniques. In contrast, in this application, the formation of the first film system does not affect the lattice of the active layer, and the formation of the second film system does not affect the lattice of the active layer. This allows for greater freedom in the selection of materials for both the first and second film systems, reducing the material limitations imposed by the active layer on the first and second film systems.

[0092] In addition, in this application, the waste heat of the active layer can be transferred without relying on the first membrane system and the second membrane system. Therefore, the restrictions on the size of the first membrane system in the first direction and the size of the second membrane system in the first direction are reduced. The size of the first membrane system in the first direction can be selected according to the design requirements, and the size of the second membrane system in the first direction can be selected according to the design requirements.

[0093] Figure 7 This is a schematic diagram showing the formation of a first semiconductor barrier layer, an active layer, and a second semiconductor barrier layer on one side of the substrate along a first direction. Figure 8 This is a schematic diagram showing the first light-transmitting heat dissipation structure positioned on the side of the active layer away from the substrate. Figure 9 In order to be in Figure 8 A schematic diagram after removing the substrate; Figure 10This is a schematic diagram showing the second light-transmitting heat dissipation structure positioned on the side of the active layer away from the first light-transmitting heat dissipation structure. Figure 11 In order to be in Figure 10 A schematic diagram showing the formation of the first and second bonding layers on the foundation. Figure 12 for Figure 11 A bottom view; Figure 13 for Figure 11 Top view; Figure 14 In order to be in Figure 11 A schematic diagram showing the formation of the first and second membrane systems based on this. Figure 15 This is a schematic diagram showing the bonding of a first heat sink to the side of a portion of the first light-transmitting heat dissipation structure facing away from the active layer, and the bonding of a second heat sink to the side of a portion of the second light-transmitting heat dissipation structure facing away from the active layer.

[0094] refer to Figure 7 An active layer 150 is formed on one side of the substrate 300 along the first direction.

[0095] In one embodiment, the material of the substrate 300 is a semiconductor material, such as a GaAs substrate.

[0096] In one embodiment, the method for fabricating a semiconductor gain chip further includes forming a first semiconductor barrier layer 160 on one side of the substrate 300 along a first direction.

[0097] In one embodiment, the process of forming the first semiconductor barrier layer 160 includes an epitaxial growth process, such as a metal-organic chemical vapor deposition process or a molecular beam epitaxy process.

[0098] The material and thickness of the first semiconductor barrier layer 160 are as described in the foregoing embodiments.

[0099] In one embodiment, forming the active layer 150 includes forming the active layer 150 on the side of the first semiconductor barrier layer 160 away from the substrate 300.

[0100] In one embodiment, the method for fabricating a semiconductor gain chip further includes forming a second semiconductor barrier layer 140 on the side of the active layer 150 opposite to the first semiconductor barrier layer 160.

[0101] The material and thickness of the second semiconductor barrier layer 140 are as described in the foregoing embodiments.

[0102] The description of the active layer 150 is the same as that in the foregoing embodiments.

[0103] In one embodiment, one side surface of the active layer 150 along the first direction is in contact with the first semiconductor barrier layer 160, and the other side surface of the active layer 150 along the first direction is in contact with the second semiconductor barrier layer 140.

[0104] refer to Figure 8 The first light-transmitting heat dissipation structure 130 is disposed on the side of the active layer 150 away from the substrate 300.

[0105] The first light-transmitting heat dissipation structure 130 is disposed on the side of the active layer 150 away from the substrate 300, including: disposing the first light-transmitting heat dissipation structure 130 on the surface of the second semiconductor barrier layer 140 away from the active layer 150. For example, intermolecular van der Waals bonding, mechanical fixation, fused eutectic bonding, or organic adhesion processes are used to dispose of the first light-transmitting heat dissipation structure 130 on the surface of the second semiconductor barrier layer 140 away from the active layer 150.

[0106] The description of the first light-transmitting heat dissipation structure 130 is as described in the foregoing embodiment.

[0107] The first light-transmitting heat dissipation structure 130 is disposed on the side surface of the second semiconductor barrier layer 140 away from the active layer 150, so as to prevent the first light-transmitting heat dissipation structure 130 from directly contacting the active layer 150, and the second semiconductor barrier layer 140 can protect the active layer 150.

[0108] The material of the second semiconductor barrier layer 140 is different from that of the active layer 150, and the material of the second semiconductor barrier layer 140 is different from that of the first light-transmitting heat dissipation structure 130.

[0109] refer to Figure 9 The first light-transmitting heat dissipation structure 130 is disposed on the surface of the active layer 150 facing away from the substrate 300, and then the substrate 300 is removed.

[0110] In one embodiment, the process of removing the substrate 300 includes an etching process, which includes one or a combination of wet etching and dry etching processes.

[0111] In one embodiment, the process for removing the substrate 300 is a wet etching process, and the etching solution used in the wet etching process is a mixed solution of ammonia and hydrogen peroxide.

[0112] In one embodiment, removing the substrate 300 includes removing the substrate 300 with the first semiconductor barrier layer 160 as an etch stop layer.

[0113] The material of the first semiconductor barrier layer 160 is different from the material of the active layer 150 and the material of the substrate 300. During the removal of the substrate 300, the materials of the first semiconductor barrier layer 160 and the active layer 150 have a certain etching ratio. The first semiconductor barrier layer 160 acts as an etching barrier layer to protect the active layer 150 and reduce etching damage to the active layer 150.

[0114] During the removal of the substrate 300, the first light-transmitting heat dissipation structure 130 can serve as a support carrier.

[0115] In one embodiment, the material of the first light-transmitting heat dissipation structure 130 is different from that of the substrate 300, so that the etching damage to the first light-transmitting heat dissipation structure 130 is less during the removal of the substrate 300.

[0116] refer to Figure 10 After removing the substrate 300, the second light-transmitting heat dissipation structure 170 is placed on the side of the active layer 150 away from the first light-transmitting heat dissipation structure 130.

[0117] The second light-transmitting heat dissipation structure 170 is disposed on the side of the active layer 150 opposite to the first light-transmitting heat dissipation structure 130, including: disposing the second light-transmitting heat dissipation structure 170 on the surface of the first semiconductor barrier layer 160 opposite to the active layer 150. For example, intermolecular van der Waals bonding, mechanical fixation, fused eutectic bonding, or organic adhesion processes are used to dispose of the second light-transmitting heat dissipation structure 170 on the surface of the first semiconductor barrier layer 160 opposite to the active layer 150.

[0118] The second light-transmitting heat dissipation structure 170 is disposed on the side surface of the first semiconductor barrier layer 160 away from the active layer 150, so as to prevent the second light-transmitting heat dissipation structure 170 from directly contacting the active layer 150. The first semiconductor barrier layer 160 can protect the active layer 150.

[0119] The second light-transmitting heat dissipation structure 170 is described in the foregoing embodiment.

[0120] refer to Figure 11 , Figure 12 and Figure 13 A first bonding layer 110 is formed on the surface of a portion of the first light-transmitting heat dissipation structure 130 that is away from the active layer 150; a second bonding layer 180 is formed on the surface of a portion of the second light-transmitting heat dissipation structure 170 that is away from the active layer 150.

[0121] Figure 12 for Figure 11 The bottom view, Figure 13 for Figure 11 Top view.

[0122] For example, a first bonding layer 110 is formed on the side surface of the edge region of the first light-transmitting heat dissipation structure 130 facing away from the active layer 150. A second bonding layer 180 is formed on the side surface of the edge region of the second light-transmitting heat dissipation structure 170 facing away from the active layer 150.

[0123] In one embodiment, forming a first bonding layer 110 on the side surface of a portion of the first light-transmitting heat dissipation structure 130 away from the active layer 150 includes: forming a first bonding material layer on the side surface of the first light-transmitting heat dissipation structure 130 away from the active layer 150; and etching the first bonding material layer to form the first bonding layer 110.

[0124] In one embodiment, forming a second bonding layer 180 on the side surface of a portion of the second light-transmitting heat dissipation structure 170 opposite to the active layer 150 includes: forming a second bonding material layer on the side surface of the second light-transmitting heat dissipation structure 170 opposite to the active layer 150; and etching the second bonding material layer to form the second bonding layer 180.

[0125] The first bonding layer 110 exposes the central region of the first light-transmitting heat dissipation structure 130. The second bonding layer 180 exposes the central region of the second light-transmitting heat dissipation structure 170.

[0126] The materials of the first bonding layer 110 and the second bonding layer 180 are the same as those in the aforementioned embodiments.

[0127] refer to Figure 14 A first film system 120 is formed on the surface of a portion of the first light-transmitting heat dissipation structure 130 that is away from the active layer 150; a second film system 200 is formed on the surface of a portion of the second light-transmitting heat dissipation structure 170 that is away from the active layer 150.

[0128] For example, a first film system 120 is formed on the side surface of the central region of the first light-transmitting heat dissipation structure 130 away from the active layer 150; and a second film system 200 is formed on the side surface of the central region of the second light-transmitting heat dissipation structure 170 away from the active layer 150.

[0129] In one embodiment, the process for forming the first film system 120 includes a thermal evaporation deposition process, an electron beam evaporation deposition process, and an ion beam assisted deposition process. The process for forming the second film system 200 includes a thermal evaporation deposition process, an electron beam evaporation deposition process, and an ion beam assisted deposition process.

[0130] Wherein, after the first film system 120 is formed, the first bonding layer 110 surrounds the sidewall of the first film system 120; after the second film system 200 is formed, the second bonding layer 180 surrounds the sidewall of the second film system 200.

[0131] In one embodiment, a first film system 120 is formed on the surface of a portion of the first light-transmitting heat dissipation structure 130 away from the active layer 150 using a thermal evaporation coating process, an electron beam evaporation coating process, and an ion beam assisted deposition process; and a second film system 200 is formed on the surface of a portion of the second light-transmitting heat dissipation structure 170 away from the active layer 150 using a thermal evaporation coating process, an electron beam evaporation coating process, and an ion beam assisted deposition process.

[0132] In one embodiment, the process may involve: forming a first film system 120 on one side surface of a first temporary substrate using a thermal evaporation deposition process, an electron beam evaporation deposition process, or an ion beam assisted deposition process; then, bonding the first film system 120 to the side surface of the central region of the first light-transmitting heat dissipation structure 130 away from the active layer 150, for example, by bonding the first film system 120 to the side surface of the central region of the first light-transmitting heat dissipation structure 130 away from the active layer 150 via intermolecular van der Waals forces; and then removing the first temporary substrate.

[0133] In one embodiment, a second film system 200 may be formed on one side surface of the second temporary substrate using a thermal evaporation deposition process, an electron beam evaporation deposition process, or an ion beam assisted deposition process. Then, the second film system 200 is bonded to the side surface of the central region of the second light-transmitting heat dissipation structure 170 away from the active layer 150, for example, by bonding the second film system 200 to the side surface of the central region of the second light-transmitting heat dissipation structure 170 away from the active layer 150 through intermolecular van der Waals forces. After that, the second temporary substrate is removed.

[0134] In this application, after the active layer 150 is formed, the first film system 120 and the second film system 200 are formed. Therefore, the process of forming the first film system 120 does not affect the crystal lattice of the active layer 150, and the process of forming the second film system 200 does not affect the crystal lattice of the active layer 150. This allows for greater freedom in the selection of materials for the first film system 120 and the second film system 200, reducing the material limitations imposed by the active layer 150 on the materials of the first film system 120 and the second film system 200.

[0135] The first membrane system 120 and the second membrane system 200 are described in the foregoing embodiments.

[0136] refer to Figure 15 The first heat sink 100 is bonded to a portion of the first light-transmitting heat dissipation structure 130 on the side away from the active layer 150, and the first heat sink 100 is located on the side of the first film system 120 along the second direction; the second heat sink 190 is bonded to a portion of the second light-transmitting heat dissipation structure 170 on the side away from the active layer 150, and the second heat sink 190 is located on the side of the second film system 200 along the second direction.

[0137] The bonding of the first heat sink 100 to the side of the first light-transmitting heat dissipation structure 130 away from the active layer 150 includes bonding the first heat sink 100 to the surface of the first bonding layer 110 away from the first light-transmitting heat dissipation structure 130.

[0138] The second heat sink 190 is bonded to the side of the second light-transmitting heat dissipation structure 170 away from the active layer 150, which includes: bonding the second heat sink 190 and the surface of the second bonding layer 180 away from the second light-transmitting heat dissipation structure 170 together.

[0139] The first heat sink 100 and the second heat sink 190 refer to the description in the foregoing embodiments.

[0140] In one embodiment, the first film system 120 is a first antireflective film system, and the second film system 200 is a second antireflective film system. The preparation method further includes: [reference needed] Figure 2 A reflector 301 is disposed on the side of the second diaphragm system 200 and the second heat sink 190 away from the active layer 150 and spaced apart from the semiconductor gain chip W and the second heat sink 190; an output mirror 400 is disposed on the side of the first diaphragm system 120 and the first heat sink 100 away from the active layer 150 and spaced apart from the semiconductor gain chip W and the first heat sink 100. A resonant cavity is formed between the reflector 301 and the output mirror 400.

[0141] In one embodiment, when the first film system 120 is a first antireflection film system and the second film system 200 is a second antireflection film system, the reflectivity of the first film system 120 at the center wavelength of the light emitted from the optically pumped semiconductor laser is less than or equal to 0.2%, and the reflectivity of the second film system 200 at the center wavelength of the light emitted from the optically pumped semiconductor laser is less than or equal to 0.2%.

[0142] When the first film system 120 is the first antireflection film system and the second film system 200 is the second antireflection film system, the reflectivity of the first film system 120 to the gain wavelength of the active layer 150 and the reflectivity of the second film system 200 to the gain wavelength of the active layer 150 are both relatively small. This suppresses the Fabry-Perot interference filtering effect between the first film system 120 and the second film system 200, and suppresses the filtering effect between the reflector 301 and the output mirror 400. This further increases the gain spectrum tuning range and further realizes a wide range of wavelength tuning.

[0143] In another embodiment, reference Figure 6 The first membrane system 120 is a first Bragg reflector, the second membrane system 200 is a second Bragg reflector, the reflectivity of the second Bragg reflector is greater than that of the first Bragg reflector, and the second membrane system 200 and the first membrane system 120 form a resonant cavity.

[0144] In another embodiment, reference Figure 4The first film system 120 is an antireflective film system, and the second film system 200 is a reflective film system. The fabrication method of the optically pumped semiconductor laser further includes: placing an output mirror 400 on the side of the first film system 120 and the first heat sink 100 away from the active layer 150 and spaced apart from the semiconductor gain chip W and the first heat sink 100; a resonant cavity is formed between the second film system 200 and the output mirror 400. When the first film system 120 is an antireflective film system, the reflectivity of the first film system 120 to the gain wavelength of the active layer 150 is relatively small, thus suppressing the Fabry-Perot interference filtering effect between the first film system 120 and the second film system 200, and suppressing the filtering effect between the second film system 200 and the output mirror 400. This further increases the gain spectral tuning range and further achieves wide-range wavelength tuning.

[0145] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An optically pumped semiconductor laser, characterized in that, Includes a semiconductor gain chip, a first heat sink, and a second heat sink; The semiconductor gain chip includes: Active layer; The first light-transmitting heat dissipation structure is located on one side of the active layer along the first direction; The second light-transmitting heat dissipation structure is located on the other side of the active layer along the first direction; A first film system is located on the surface of a portion of the first light-transmitting and heat-dissipating structure opposite to the active layer; and The second film system is located on the surface of a portion of the second light-transmitting heat dissipation structure on the side opposite to the active layer; Wherein, the first heat sink is located on the side of the first light-transmitting heat dissipation structure away from the active layer, and the first heat sink is located on the side of the first film system along the second direction; the second heat sink is located on the side of the second light-transmitting heat dissipation structure away from the active layer, and the second heat sink is located on the side of the second film system along the second direction. Wherein, the first light-transmitting heat dissipation structure has an absorptivity of less than or equal to 20% within the gain wavelength range of the active layer, and the thermal conductivity of the first light-transmitting heat dissipation structure is greater than the thermal conductivity of the first film system; the thickness of the first light-transmitting heat dissipation structure in the first direction is greater than the thickness of the first film system in the first direction; the second light-transmitting heat dissipation structure has an absorptivity of less than or equal to 20% within the gain wavelength range of the active layer, and the thermal conductivity of the second light-transmitting heat dissipation structure is greater than the thermal conductivity of the second film system; the thickness of the second light-transmitting heat dissipation structure in the first direction is greater than the thickness of the second film system in the first direction; Wherein, the first direction and the second direction are perpendicular.

2. The optically pumped semiconductor laser according to claim 1, characterized in that, The thickness of the first light-transmitting heat dissipation structure in the first direction is 500nm~10mm; the thickness of the second light-transmitting heat dissipation structure in the first direction is 500nm~10mm.

3. The optically pumped semiconductor laser according to claim 1, characterized in that, The material of the first light-transmitting heat dissipation structure includes any one of diamond, silicon carbide, sapphire, and graphene; the material of the second light-transmitting heat dissipation structure includes any one of diamond, silicon carbide, sapphire, and graphene.

4. The optically pumped semiconductor laser according to claim 1, characterized in that, The semiconductor gain chip further includes: a first bonding layer located between the first heat sink and the first light-transmitting heat dissipation structure; and a second bonding layer located between the second heat sink and the second light-transmitting heat dissipation structure.

5. The optically pumped semiconductor laser according to claim 1, characterized in that, The semiconductor gain chip further includes: a first semiconductor blocking layer located between the active layer and the second light-transmitting heat dissipation structure; and a second semiconductor blocking layer located between the active layer and the first light-transmitting heat dissipation structure.

6. The optically pumped semiconductor laser according to claim 5, characterized in that, The thickness of the first semiconductor barrier layer in the first direction is 10 nm to 20 μm; The thickness of the second semiconductor barrier layer in the first direction is 10 nm to 20 μm.

7. The optically pumped semiconductor laser according to claim 1, characterized in that, The first film system is a first antireflective film system, and the second film system is a second antireflective film system; The optically pumped semiconductor laser further includes a reflector and an output mirror; the reflector is located on the side of the second film system and the second heat sink away from the active layer and is spaced apart from the semiconductor gain chip and the second heat sink; the output mirror is located on the side of the first film system and the first heat sink away from the active layer and is spaced apart from the semiconductor gain chip and the first heat sink; a resonant cavity is formed between the reflector and the output mirror.

8. The optically pumped semiconductor laser according to claim 1, characterized in that, The first film system is a first Bragg reflector, the second film system is a second Bragg reflector, the reflectivity of the second Bragg reflector is greater than that of the first Bragg reflector, and the second film system and the first film system form a resonant cavity.

9. The optically pumped semiconductor laser according to claim 1, characterized in that, The first film system is an antireflective film system, and the second film system is a reflective film system; The optically pumped semiconductor laser further includes: an output mirror located on the side of the first film system and the first heat sink away from the active layer and spaced apart from the semiconductor gain chip and the first heat sink; and a resonant cavity is formed between the second film system and the output mirror.

10. A method for fabricating an optically pumped semiconductor laser, characterized in that, include: Forming a semiconductor gain chip includes: forming an active layer on one side of a substrate along a first direction; disposing a first light-transmitting heat dissipation structure on the side of the active layer opposite to the substrate; then removing the substrate; after removing the substrate, disposing a second light-transmitting heat dissipation structure on the side of the active layer opposite to the first light-transmitting heat dissipation structure; forming a first film system on a portion of the surface of the first light-transmitting heat dissipation structure opposite to the active layer; forming a second film system on a portion of the surface of the second light-transmitting heat dissipation structure opposite to the active layer; and... The first heat sink is bonded to a portion of the first light-transmitting heat dissipation structure on the side opposite to the active layer, and the first heat sink is located on the side of the first film system along the second direction. The second heat sink is bonded to a portion of the second light-transmitting heat dissipation structure on the side opposite to the active layer, and the second heat sink is located on the side of the second film system along the second direction. Wherein, the first light-transmitting heat dissipation structure has an absorptivity of less than or equal to 20% within the gain wavelength range of the active layer, and the thermal conductivity of the first light-transmitting heat dissipation structure is greater than the thermal conductivity of the first film system; the thickness of the first light-transmitting heat dissipation structure in the first direction is greater than the thickness of the first film system in the first direction; the second light-transmitting heat dissipation structure has an absorptivity of less than or equal to 20% within the gain wavelength range of the active layer, and the thermal conductivity of the second light-transmitting heat dissipation structure is greater than the thermal conductivity of the second film system; the thickness of the second light-transmitting heat dissipation structure in the first direction is greater than the thickness of the second film system in the first direction; Wherein, the first direction is perpendicular to the second direction.

11. The method for fabricating an optically pumped semiconductor laser according to claim 10, characterized in that, The formation of a semiconductor gain chip also includes: A first semiconductor barrier layer is formed on one side of the substrate along the first direction; The formation of the active layer includes: forming the active layer on the side of the first semiconductor barrier layer away from the substrate; The removal of the substrate includes: removing the substrate using the first semiconductor barrier layer as an etch stop layer; The provision of the second light-transmitting heat dissipation structure on the side of the active layer away from the first light-transmitting heat dissipation structure includes: the second light-transmitting heat dissipation structure being disposed on the surface of the first semiconductor barrier layer away from the active layer.

12. The method for fabricating an optically pumped semiconductor laser according to claim 11, characterized in that, The semiconductor gain chip is further formed by: forming a second semiconductor barrier layer on the side of the active layer opposite to the first semiconductor barrier layer; The provision of the first light-transmitting heat dissipation structure on the side of the active layer away from the substrate includes: the first light-transmitting heat dissipation structure being disposed on the surface of the second semiconductor barrier layer away from the active layer.

13. The method for fabricating an optically pumped semiconductor laser according to claim 10, characterized in that, The semiconductor gain chip formation further includes: forming a first bonding layer on a portion of the first light-transmitting heat dissipation structure on the side surface opposite to the active layer; forming a second bonding layer on a portion of the second light-transmitting heat dissipation structure on the side surface opposite to the active layer; wherein, after the first film system is formed, the first bonding layer surrounds the sidewall of the first film system; after the second film system is formed, the second bonding layer surrounds the sidewall of the second film system. The first heat sink is bonded to the side of the first light-transmitting heat dissipation structure opposite to the active layer, which includes: bonding the first heat sink to the surface of the first bonding layer opposite to the first light-transmitting heat dissipation structure. The step of bonding the second heat sink to a portion of the second light-transmitting heat dissipation structure on the side away from the active layer includes: bonding the second heat sink to the surface of the second bonding layer on the side away from the second light-transmitting heat dissipation structure.

14. The method for fabricating an optically pumped semiconductor laser according to claim 10, characterized in that, The first film system is a first antireflective film system, and the second film system is a second antireflective film system; The fabrication method of the optically pumped semiconductor laser further includes: placing a reflector on the side of the second film system and the second heat sink away from the active layer and spaced apart from the semiconductor gain chip and the second heat sink; placing an output mirror on the side of the first film system and the first heat sink away from the active layer and spaced apart from the semiconductor gain chip and the first heat sink; and forming a resonant cavity between the reflector and the output mirror.

15. The method for fabricating an optically pumped semiconductor laser according to claim 10, characterized in that, The first film system is a first Bragg reflector, the second film system is a second Bragg reflector, the reflectivity of the second Bragg reflector is greater than that of the first Bragg reflector, and the second film system and the first film system form a resonant cavity.

16. The method for fabricating an optically pumped semiconductor laser according to claim 10, characterized in that, The first film system is an antireflective film system, and the second film system is a reflective film system; The method for fabricating the optically pumped semiconductor laser further includes: placing an output mirror on the side of the first film system and the first heat sink away from the active layer and spaced apart from the semiconductor gain chip and the first heat sink; and forming a resonant cavity between the second film system and the output mirror.

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