External cavity semiconductor laser array structure

Abstract

The invention provides an external cavity semiconductor laser array structure, relates to the technical field of semiconductor lasers, and is used for solving the problem that a conventional heat dissipation mode is difficult to meet the heat dissipation requirements and thermal crosstalk of an external cavity semiconductor laser and an array thereof. And the output power and the power application of the external cavity semiconductor laser and the array thereof are limited. The structure comprises a laser chip used for providing optical gain; the outer cavity reflector and the laser chip jointly form an outer resonant cavity and are used for providing optical feedback; the outer cavity cooling liquid is filled between the laser chip and the outer cavity reflecting mirror and is used for absorbing heat generated in the working process of the laser chip; wherein the refractive index of the external cavity cooling liquid under the emission wavelength of the laser is matched with the cavity length of the external resonant cavity, so that the external resonant cavity can meet the resonance condition, and laser output is realized.

Description

Technical Field

[0001] The present disclosure relates to the technical field of semiconductor lasers, and more specifically, to an external cavity semiconductor laser array structure. Background Art

[0002] Semiconductor lasers have the advantages of small size, direct electrical injection, high efficiency and low cost, and have been widely used in optical communications and sensing, industrial processing and solid-state laser pumping. However, semiconductor lasers also have disadvantages such as poor output beam quality, low spectral purity and difficulty in achieving intracavity regulation, which limits the further expansion of their application areas. External cavity semiconductor lasers combine the advantages of semiconductor lasers and solid-state lasers, use semiconductor materials as gain chips, and combine external optical elements such as reflectors to expand the resonant cavity. External cavity semiconductor lasers can provide a wider wavelength tuning range, achieve narrow linewidth lasers, improve beam quality and achieve higher output power, meeting a wider range of application needs.

[0003] In order to improve the output power of external cavity semiconductor lasers, they are often integrated into array structures, including one-dimensional linear arrays and two-dimensional stacked arrays and planar arrays. However, the thermal effect of external cavity semiconductor laser arrays seriously restricts their performance.

[0004] In the process of realizing the concept of the present disclosure, the inventors found that there are at least the following problems in the related art: the conventional heat dissipation methods in the prior art are difficult to meet the heat dissipation requirements and thermal crosstalk problems of external cavity semiconductor lasers and their arrays, thereby limiting the output power and power application of external cavity semiconductor lasers and their arrays. Summary of the invention

[0005] In view of this, the present disclosure provides an external cavity semiconductor laser array structure to solve the technical problem that conventional heat dissipation methods are difficult to meet the heat dissipation requirements and thermal crosstalk of external cavity semiconductor lasers and their arrays, thereby limiting the output power and power application of external cavity semiconductor lasers and their arrays.

[0006] One aspect of the present disclosure provides an external cavity semiconductor laser array structure, comprising: a laser chip, which is used to provide optical gain; an external cavity reflector, which forms an external resonant cavity together with the laser chip, and is used to provide optical feedback; an external cavity coolant, which is filled between the laser chip and the external cavity reflector, and is used to absorb the heat generated by the laser chip during operation; wherein the refractive index of the external cavity coolant at the laser emission wavelength matches the cavity length of the external resonant cavity, so that the external resonant cavity can meet the resonance condition, thereby realizing laser output.

[0007] According to an embodiment of the present disclosure, the laser chip is configured as a vertical cavity surface emitting laser chip, wherein the vertical cavity surface emitting laser chip includes: a first substrate; a first distributed Bragg reflection layer, disposed on the first substrate, for providing optical feedback, wherein the reflectivity of the first distributed Bragg reflection layer at the laser emission wavelength is greater than a first reflectivity threshold; an active region, disposed on the first distributed Bragg reflection layer, for converting light energy into photons under light injection, amplifying the light intensity by stimulated radiation, and forming optical gain.

[0008] According to an embodiment of the present disclosure, a vertical cavity surface emitting laser chip includes: a second distributed Bragg reflection layer, which is arranged on the active area, and the reflectivity of the second distributed Bragg reflection layer at the laser emission wavelength is less than a first reflectivity threshold; wherein the second distributed Bragg reflection layer, the active area, and the first distributed Bragg reflection layer together form an internal resonant cavity, which is used to convert electrical energy into photons under electrical injection, amplify the light intensity by stimulated radiation, and form optical gain.

[0009] According to an embodiment of the present disclosure, the laser chip is configured as an edge-emitting laser chip, wherein the edge-emitting laser chip comprises: a second substrate; a gain region, disposed on the second substrate, for providing optical gain, wherein the gain region comprises: a first cavity facet, disposed at an end away from the external cavity reflector, wherein the reflectivity of the first cavity facet at the laser emission wavelength is greater than a second reflectivity threshold; a second cavity facet, disposed at an end close to the external cavity reflector, wherein the reflectivity of the second cavity facet at the laser emission wavelength is less than the second reflectivity threshold.

[0010] According to an embodiment of the present disclosure, the laser chip further includes: a bottom electrode disposed at the bottom end of the first substrate or the bottom end of the second substrate; and a top electrode disposed at the top end of the laser chip.

[0011] According to an embodiment of the present disclosure, the external cavity cooling liquid is configured as an electrically insulating liquid that is transparent at the laser emission wavelength and below a laser absorptivity threshold.

[0012] According to an embodiment of the present disclosure, the external cavity cooling liquid is configured to be in a first filling state, wherein in the first filling state, there is no gas space or no vacuum space in the external resonant cavity.

[0013] According to an embodiment of the present disclosure, the external cavity cooling liquid is configured to be in a second filling state, wherein in the second filling state, there is a gas space or a vacuum space in the external resonant cavity.

[0014] According to an embodiment of the present disclosure, the external cavity mirror is configured to be able to control the phase, mode and polarization of the laser.

[0015] According to an embodiment of the present disclosure, the external resonant cavity is configured to be able to improve device performance by inserting an optical element.

[0016] Compared with the prior art, the external cavity semiconductor laser array structure provided by the present disclosure has at least the following beneficial effects:

[0017] The external cavity semiconductor laser array structure provided by the present invention uses a coolant as an external cavity medium to fill between a laser chip and an external cavity reflector, utilizes the coolant to cool a side of the laser chip close to the external cavity, and combines conventional semiconductor heat dissipation methods at the same time, so that the laser can achieve all-round and multi-angle heat dissipation, thereby improving the working performance of the laser and increasing the reliability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0019] Figure 1 A schematic diagram of a structure of an external cavity semiconductor laser array structure according to a first embodiment of the present disclosure is shown;

[0020] Figure 2 Schematically shows a side view of an external cavity semiconductor laser array structure according to a second embodiment of the present disclosure;

[0021] Figure 3 A top view of an external cavity semiconductor laser array structure according to a second embodiment of the present disclosure is schematically shown.

[0022] [Reference Signs]

[0023] 1-External cavity reflector;

[0024] 2-External cavity cooling liquid;

[0025] 3-vertical cavity surface emitting laser chip; 31-first substrate; 32-first distributed Bragg reflection layer; 33-active area; 34-second distributed Bragg reflection layer;

[0026] 4-edge emitting laser chip; 41-second substrate; 42-gain region; 421-first cavity surface; 422-second cavity surface;

[0027] 5- bottom electrode;

[0028] 6- Top electrode. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0030] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0031] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0032] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0033] Semiconductor lasers have the advantages of small size, direct electrical injection, high efficiency and low cost, and have been widely used in optical communications and sensing, industrial processing and solid-state laser pumping. However, semiconductor lasers also have disadvantages such as poor output beam quality, low spectral purity and difficulty in achieving intracavity regulation, which limits the further expansion of their application areas. External cavity semiconductor lasers combine the advantages of semiconductor lasers and solid-state lasers, use semiconductor materials as gain chips, and combine external optical elements such as reflectors to expand the resonant cavity. External cavity semiconductor lasers can provide a wider wavelength tuning range, achieve narrow linewidth lasers, improve beam quality and achieve higher output power, meeting a wider range of application needs.

[0034] In order to improve the output power of external cavity semiconductor lasers, external cavity semiconductor lasers are often integrated into array structures, including one-dimensional linear arrays and two-dimensional stacked arrays and planar arrays. However, the thermal effect of the external cavity semiconductor laser array seriously restricts its performance. On the one hand, the external cavity semiconductor laser array has a large thermal power density when working; on the other hand, due to the low thermal conductivity of semiconductor materials, the thermal resistance of the device is large, and the waste heat generated during operation is difficult to dissipate from the active area of ​​​​light and heat; further, external cavity semiconductor lasers usually use air or solid media as the external cavity. The thermal conductivity of these materials is also low, and the heat cannot be extracted in time on the light-emitting side. For external cavity semiconductor lasers and their arrays, the conventional heat dissipation method is to transfer heat to the substrate and then dissipate heat through a heat sink. On the one hand, this heat dissipation method cannot meet the requirements of high-power external cavity semiconductor lasers and their arrays for heat dissipation efficiency; on the other hand, this heat dissipation method can only dissipate heat downward along the substrate direction, and cannot extract heat in other directions, so that the temperature difference between the center unit and the edge unit in the array area is large, which leads to the problem of spectrum broadening and performance degradation, that is, the problem of thermal crosstalk.

[0035] In the process of realizing the concept of the present disclosure, the inventors found that there are at least the following problems in the related art: the conventional heat dissipation methods in the prior art are difficult to meet the heat dissipation requirements and thermal crosstalk problems of external cavity semiconductor lasers and their arrays, thereby limiting the output power and power application of external cavity semiconductor lasers and their arrays.

[0036] Based on this, an embodiment of the present disclosure provides an external cavity semiconductor laser array structure to solve the technical problem that conventional heat dissipation methods are difficult to meet the heat dissipation requirements and thermal crosstalk of external cavity semiconductor lasers and their arrays, thereby limiting the output power and power application of external cavity semiconductor lasers and their arrays.

[0037] The structure includes: a laser chip for providing optical gain; an external cavity reflector, which forms an external resonant cavity together with the laser chip for providing optical feedback; an external cavity coolant, which is filled between the laser chip and the external cavity reflector and is used to absorb the heat generated by the laser chip during operation; wherein the refractive index of the external cavity coolant at the laser emission wavelength matches the cavity length of the external resonant cavity, so that the external resonant cavity can meet the resonance condition, thereby realizing laser output.

[0038] The external cavity semiconductor laser array structure provided by the embodiment of the present disclosure fills the cooling liquid as the external cavity medium between the laser chip and the external cavity reflector, uses the cooling liquid to cool the side of the laser chip close to the external cavity, and combines with the conventional semiconductor heat dissipation method, so that the laser can achieve all-round and multi-angle heat dissipation, improves the working performance of the laser, and increases the reliability of the device.

[0039] According to an embodiment of the present disclosure, the laser chip may include: a vertical cavity surface emitting laser chip or an edge emitting laser chip.

[0040] When the laser chip is a vertical cavity surface emitting laser chip, the structure adopts a surface emission method, that is, the light emitting direction of the laser is perpendicular to the substrate.

[0041] When the laser chip is an edge-emitting laser chip, the structure adopts an edge-emitting mode, that is, the light emitting direction of the laser is parallel to the substrate.

[0042] It should be understood that no matter surface emission or edge emission is adopted, the external cavity reflector is always arranged perpendicular to the light emitting direction.

[0043] In order to make the purpose, technical solutions and advantages of the present disclosure more clearly understood, two embodiments (a first embodiment and a second embodiment) are provided for a vertical cavity surface emitting laser chip and an edge emitting laser chip respectively, and the present disclosure is further described in detail with reference to the accompanying drawings.

[0044] First embodiment

[0045] Figure 1 The structure diagram of the external cavity semiconductor laser array structure according to the first embodiment of the present disclosure is schematically shown.

[0046] like Figure 1 As shown, the external cavity semiconductor laser array structure of this embodiment includes: a vertical cavity surface emitting laser chip 3, an external cavity reflector 1 and an external cavity coolant 2.

[0047] The vertical cavity surface emitting laser chip 3 is used to provide optical gain.

[0048] The external cavity reflector 1 and the vertical cavity surface emitting laser chip 3 together form an external resonant cavity for providing optical feedback. The external cavity reflector 1 is a medium with a certain reflectivity at the emission wavelength of the laser.

[0049] The external cavity coolant 2 is filled between the vertical cavity surface emitting laser chip 3 and the external cavity reflector 1, and is used to absorb the heat generated by the vertical cavity surface emitting laser chip 3 during operation, wherein the refractive index of the external cavity coolant 2 at the laser emission wavelength matches the cavity length of the external resonant cavity, so that the external resonant cavity can meet the resonance condition, thereby realizing laser output.

[0050] In this embodiment, the vertical cavity surface emitting laser chip 3 may specifically include: a first substrate 31 , a first distributed Bragg reflection layer 32 and an active region 33 .

[0051] from Figure 1Seen in the direction shown, the first distributed Bragg reflection layer 32 is disposed on the first substrate 31 for providing optical feedback. The reflectivity of the first distributed Bragg reflection layer 32 at the laser emission wavelength is greater than a first reflectivity threshold (the first reflectivity threshold can be set to 99.5%, for example) to provide sufficient optical feedback.

[0052] The active region 33 is disposed on the first distributed Bragg reflector layer 32 and is used to convert light energy into photons under light injection, amplify light intensity through stimulated radiation, and form optical gain.

[0053] In this embodiment, the vertical cavity surface emitting laser chip 3 may further include: a second distributed Bragg reflection layer 34 , a bottom electrode 5 and a top electrode 6 .

[0054] The second distributed Bragg reflection layer 34 is disposed on the active region 33 , and the reflectivity of the second distributed Bragg reflection layer 34 at the laser emission wavelength is less than the first reflectivity threshold, that is, less than 99.5%, and preferably, can be less than 50%.

[0055] The bottom electrode 5 is disposed at the bottom end of the first substrate 31 .

[0056] The top electrode 6 is disposed on the top of the second distributed Bragg reflector layer 34 .

[0057] In this embodiment, the active region 33 , the second distributed Bragg reflective layer 34 and the top electrode 6 are arranged two-dimensionally and periodically on the first distributed Bragg reflective layer 32 .

[0058] The second distributed Bragg reflector 34 can form an internal resonant cavity together with the active area 33 and the first distributed Bragg reflector 32. Combined with the bottom electrode 5 and the top electrode 6, it can convert electrical energy into photons under electrical injection, amplify the light intensity through stimulated radiation, and form optical gain.

[0059] In this embodiment, the external cavity coolant 2 is filled in the external resonant cavity between the second distributed Bragg reflector 34 and the external cavity reflector 1. The external cavity coolant 2 is a non-toxic, low-viscosity, transparent and low-absorption electrical insulating liquid at the laser emission wavelength, such as fluorinated liquid, silicone oil, etc.

[0060] The dielectric strength of the external cavity coolant 2 is greater than 25 kV, that is, it has high electrical strength, so that the components in the laser will not short-circuit when immersed in the external cavity coolant 2, and the absorption rate of the external cavity coolant 2 at the corresponding wavelength of the laser light emission is less than 10 -4 cm -1 , indicating that the absorption of the emitted light waves by the external cavity coolant 2 can be ignored.

[0061] In this embodiment, the outer cavity coolant 2 can be configured to be in a first filling state (fully filled) or a second filling state (partially filled).

[0062] In the fully filled state, the external cavity coolant 2 is completely filled in the external resonant cavity, so that there is no gas space or vacuum space in the external resonant cavity.

[0063] In the partially filled state, the external cavity coolant 2 is partially filled in the external resonant cavity, so that a certain gas space or vacuum space is retained in the external resonant cavity. At this time, the length of the external resonant cavity can be changed accordingly, so that the entire cavity meets the resonance conditions and forms laser output.

[0064] In this embodiment, the external cavity reflector 1 is configured to be able to regulate the phase, mode and polarization of the laser. For example, the external cavity reflector 1 can be modified, such as optical coating, grating formation and metasurface formation.

[0065] In this embodiment, the external resonant cavity may also be configured to improve device performance by inserting an optical element, and the inserted optical element will not be affected by the external cavity coolant 2 .

[0066] Second embodiment

[0067] Figure 2 A side view of an external cavity semiconductor laser array structure according to a second embodiment of the present disclosure is schematically shown.

[0068] like Figure 2 As shown, the external cavity semiconductor laser array structure of this embodiment includes: an edge emitting laser chip 4, an external cavity reflector 1 and an external cavity coolant 2.

[0069] The edge-emitting laser chip 4 is used to provide optical gain.

[0070] The external cavity reflector 1 and the edge-emitting laser chip 4 together form an external resonant cavity for providing optical feedback. The external cavity reflector 1 is a medium with a certain reflectivity at the emission wavelength of the laser.

[0071] The external cavity coolant 2 is filled between the edge-emitting laser chip 4 and the external cavity reflector 1, and is used to absorb the heat generated by the edge-emitting laser chip 4 during operation. The refractive index of the external cavity coolant 2 at the laser emission wavelength matches the cavity length of the external resonant cavity, so that the external resonant cavity can meet the resonance condition, thereby realizing laser output.

[0072] In this embodiment, the edge-emitting laser chip 4 may specifically include: a second substrate 41 , a gain region 42 , a bottom electrode 5 and a top electrode 6 .

[0073] from Figure 2Looking from the direction shown, the gain region 42 is disposed on the second substrate 41 to provide optical gain.

[0074] The gain region 42 includes a first cavity surface (rear cavity surface) 421 and a second cavity surface (front cavity surface) 422 .

[0075] The first cavity surface 421 is arranged at one end away from the external cavity reflector 1, and the reflectivity of the first cavity surface 421 at the laser emission wavelength is greater than a second reflectivity threshold (the second reflectivity threshold can be set to 90%, for example) to provide sufficient light feedback.

[0076] The second cavity surface 422 is arranged at one end close to the external cavity reflector 1. The reflectivity of the second cavity surface 422 at the laser emission wavelength is less than the second reflectivity threshold, that is, less than 90%. Preferably, it can be less than 10%, or even completely transparent, so that the internal cavity cannot form lasing.

[0077] In this embodiment, the front cavity surface, the external cavity coolant 2 and the external cavity reflector 1 form an external resonant cavity, and the distance between the front cavity surface and the external cavity reflector 1 matches the refractive index of the external cavity coolant 2 at the emission wavelength of the laser, so that the overall cavity meets the resonance condition.

[0078] Figure 3 A top view of an external cavity semiconductor laser array structure according to a second embodiment of the present disclosure is schematically shown.

[0079] like Figure 3 As shown, in the external cavity semiconductor laser array structure of this embodiment, the edge emitting laser chips 4 are arranged in a one-dimensional periodic manner to form a one-dimensional linear array, thereby increasing the number of integrated edge emitting laser chips 4 and improving the output power.

[0080] In this embodiment, the external cavity coolant 2 is filled between the front cavity surface of the gain region 42 and the external cavity reflector 1, and is in close contact with the second substrate 41 and the gain region 42. The external cavity coolant 2 is a non-toxic, low-viscosity, electrically insulating liquid that is transparent at the laser emission wavelength and has a low absorption rate, so that the laser will not be short-circuited even if it is immersed in the external cavity coolant 2.

[0081] Since the gain region 42 and the second substrate 41 are immersed in the external cavity coolant 2, combined with the heat dissipation method of the traditional heat sink, the gain region 42 and the second substrate 41 can be omni-directionally and multi-angledly cooled. Not only the heat dissipation efficiency is improved, the working performance of the device is improved, and at the same time, since the rear cavity surface, the front cavity surface and the external cavity reflector 1 are immersed in the external cavity coolant 2, the thermal lens effect is greatly alleviated.

[0082] In this embodiment, the outer cavity coolant 2 can be specifically configured to be in a first filling state (fully filled) or a second filling state (partially filled).

[0083] In the fully filled state, the external cavity coolant 2 is completely filled in the external resonant cavity, so that there is no gas space or vacuum space in the external resonant cavity.

[0084] In the partially filled state, the external cavity coolant 2 is partially filled in the external resonant cavity, so that a certain gas space or vacuum space is retained in the external resonant cavity. At this time, the length of the external resonant cavity can be changed accordingly, so that the entire cavity meets the resonance conditions and forms laser output.

[0085] In this embodiment, the external cavity reflector 1 is configured to be able to regulate the phase, mode and polarization of the laser. For example, the external cavity reflector 1 can be modified, such as optical coating, grating formation and metasurface formation.

[0086] In this embodiment, the external resonant cavity may also be configured to improve device performance by inserting an optical element, and the inserted optical element will not be affected by the external cavity coolant 2 .

[0087] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram may represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box may also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions. It can be understood by those skilled in the art that the features recorded in the various embodiments of the present disclosure can be combined and / or combined in a variety of ways, even if such a combination or combination is not explicitly recorded in the present disclosure. In particular, without departing from the spirit and teaching of the present disclosure, the features described in the various embodiments of the present disclosure may be combined and / or combined in a variety of ways. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0088] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. An external cavity semiconductor laser array structure, characterized in that: The structure comprises: A laser chip for providing optical gain; An external cavity reflector, which forms an external resonant cavity together with the laser chip and is used to provide optical feedback; External cavity coolant, filled between the laser chip and the external cavity reflector, for absorbing the heat generated by the laser chip during operation; The refractive index of the external cavity cooling liquid at the laser emission wavelength matches the cavity length of the external resonant cavity, so that the external resonant cavity can meet the resonance condition, thereby realizing laser output.

2. The structure according to claim 1, characterized in that: The laser chip is configured as a vertical cavity surface emitting laser chip, wherein the vertical cavity surface emitting laser chip comprises: a first substrate; A first distributed Bragg reflection layer, disposed on the first substrate, for providing optical feedback, wherein a reflectivity of the first distributed Bragg reflection layer at a laser emission wavelength is greater than a first reflectivity threshold; The active region is arranged on the first distributed Bragg reflection layer, and is used for converting light energy into photons under light injection, amplifying light intensity through stimulated radiation, and forming light gain.

3. The structure according to claim 2, characterized in that: The vertical cavity surface emitting laser chip further comprises: A second distributed Bragg reflection layer is disposed on the active region, wherein a reflectivity of the second distributed Bragg reflection layer at a laser emission wavelength is less than a first reflectivity threshold; The second distributed Bragg reflector layer, the active region and the first distributed Bragg reflector layer together form an internal resonant cavity for converting electrical energy into photons under electrical injection, amplifying light intensity through stimulated radiation, and forming optical gain.

4. The structure according to claim 1, characterized in that The laser chip is configured as an edge emitting laser chip, wherein the edge emitting laser chip comprises: a second substrate; A gain region, disposed on the second substrate, for providing optical gain, wherein the gain region comprises: A first cavity surface, arranged at an end away from the external cavity reflector, wherein the reflectivity of the first cavity surface at the laser emission wavelength is greater than a second reflectivity threshold; The second cavity surface is arranged at one end close to the external cavity reflection mirror, wherein the reflectivity of the second cavity surface at the laser emission wavelength is less than a second reflectivity threshold.

5. The structure according to any one of claims 3 or 4, characterized in that: The laser chip also includes: A bottom electrode, disposed at the bottom end of the first substrate or the bottom end of the second substrate; The top electrode is arranged on the top of the laser chip.

6. The structure according to claim 1, characterized in that The external cavity cooling liquid is configured as an electrically insulating liquid that is transparent at the laser emission wavelength and below a laser absorptivity threshold.

7. The structure according to claim 1, characterized in that The external cavity cooling liquid is configured to be in a first filling state, wherein, in the first filling state, there is no gas space or no vacuum space in the external resonant cavity.

8. The structure according to claim 1, characterized in that The external cavity cooling liquid is configured to be in a second filling state, wherein in the second filling state, a gas space or a vacuum space exists in the external resonant cavity.

9. The structure according to claim 1, characterized in that The external cavity mirror is configured to be able to control the phase, mode and polarization of the laser.

10. The structure according to claim 1, characterized in that The external resonant cavity is configured to enhance device performance by inserting optical elements.

Images