Extracavity semiconductor laser array structure

Abstract

The disclosure provides an external cavity semiconductor laser array structure, relates to the technical field of semiconductor lasers, and aims to solve the technical problems that the conventional heat dissipation mode is difficult to meet the heat dissipation demand and heat crosstalk problem of the external cavity semiconductor laser and the array, and further limits the output power and power application of the external cavity semiconductor laser and the array. The structure comprises: a laser chip for providing optical gain; an external cavity mirror which forms an external resonant cavity together with the laser chip and is used for providing optical feedback; and an external cavity cooling liquid which is filled between the laser chip and the external cavity mirror and is used for absorbing 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.

Description

TECHNICAL FIELD

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

[0002] Semiconductor lasers have the advantages of small volume, direct electrical injection, high efficiency and low cost, and have been widely used in optical communication and sensing, industrial processing and solid laser pumping fields. However, semiconductor lasers also have the disadvantages of poor output beam quality, low spectral purity and difficulty in realizing in-cavity regulation, which limit the further expansion of their application fields. External cavity semiconductor lasers combine the advantages of semiconductor lasers and solid-state lasers, using semiconductor materials as gain chips and combining external optical elements such as mirrors to expand the resonant cavity. External cavity semiconductor lasers can provide a wider wavelength tuning range, realize narrow linewidth lasers, improve beam quality and achieve higher output power, meeting more extensive application requirements.

[0003] 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 surface arrays. However, the thermal effect of external cavity semiconductor laser arrays seriously restricts their performance.

[0004] In the process of implementing the present concept, the inventors have found that the conventional heat dissipation methods in the prior art cannot meet the heat dissipation requirements and thermal crosstalk problems of external cavity semiconductor lasers and their arrays, thereby limiting the output power and power applications of external cavity semiconductor lasers and their arrays. SUMMARY

[0005] Therefore, the present disclosure provides an external cavity semiconductor laser array structure to solve the technical problem that the conventional heat dissipation methods cannot meet the heat dissipation requirements and thermal crosstalk problems of external cavity semiconductor lasers and their arrays, thereby limiting the output power and power applications 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 for providing optical gain; an external cavity mirror, which forms an external resonant cavity with the laser chip, for providing optical feedback; an external cavity cooling liquid, which is filled between the laser chip and the external cavity mirror, for absorbing heat generated by the laser chip during operation; wherein 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.

[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 comprises: a first substrate; a first distributed Bragg reflector layer disposed on the first substrate and configured to provide optical feedback, wherein the first distributed Bragg reflector layer has a reflectivity greater than a first reflectivity threshold at a laser emission wavelength; and an active region disposed on the first distributed Bragg reflector layer and configured to convert optical energy into photons under optical injection, amplify optical intensity through stimulated emission, and form optical gain.

[0008] According to an embodiment of the present disclosure, the vertical cavity surface emitting laser chip comprises: a second distributed Bragg reflector layer disposed on the active region, wherein the second distributed Bragg reflector layer has a reflectivity less than the first reflectivity threshold at the laser emission wavelength; and wherein the second distributed Bragg reflector layer, the active region, and the first distributed Bragg reflector layer collectively form an internal resonant cavity configured to convert electrical energy into photons under electrical injection, amplify optical intensity through stimulated emission, 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; and a gain region disposed on the second substrate and configured to provide optical gain, wherein the gain region comprises: a first cavity facet disposed at a distal end from an external cavity mirror, wherein the first cavity facet has a reflectivity greater than a second reflectivity threshold at the laser emission wavelength; and a second cavity facet disposed at a proximal end to the external cavity mirror, wherein the second cavity facet has a reflectivity less than the second reflectivity threshold at the laser emission wavelength.

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

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

[0012] According to an embodiment of the present disclosure, the external cavity coolant is configured 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 coolant is configured 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 capable of adjusting 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 capable of improving device performance by inserting optical elements.

[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 disclosure fills the cooling liquid as the external cavity medium between the laser chip and the external cavity mirror, cools the side of the laser chip close to the external cavity by the cooling liquid, and combines the conventional semiconductor heat dissipation mode, so that the laser can realize omnidirectional and multi-angle heat dissipation, improve the working performance of the laser, and increase the reliability of the device. BRIEF DESCRIPTION OF DRAWINGS

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

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

[0020] 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;

[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 NUMERALS

[0023] 1-external cavity mirror;

[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 region; 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. It should be understood, however, that the description is merely exemplary and is not intended to limit the scope of the present disclosure. In the following detailed description of the embodiments, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, it would be apparent to those skilled in the art that the embodiments can be practiced without these specific details. In other instances, well-known structures and functions have been described in detail in order to avoid obscuring the concepts of the present disclosure.

[0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the term "includes" and tautological expressions thereof, such as "including," "includes," "include," "contains," "containing," and so forth, shall be read expansively and without limitation. The terms "comprising," "comprise" and / or "comprises" and tautological expressions thereof (for example, "comprising a," "comprises an," etc.) shall be interpreted as per the term "including" and tautological expressions thereof.

[0031] All terms used herein (including technical and scientific terms) have the meanings commonly understood by one of ordinary skill in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted as having a meaning that is consistent with the context of the specification, and not to be interpreted in an idealized or overly formal way.

[0032] In the case of using expressions similar to "at least one of A, B, and C, etc.", it should generally be interpreted to include any of them, to exclude the other(s) of any of them, or to include some of them. For example, the expression "at least one of A, B, and C" should be interpreted to include only A, only B, only C, only A and B, only A and C, only B and C, only A, B, and C, etc.

[0033] Semiconductor lasers have the advantages of small volume, direct electrical injection, high efficiency, and low cost, and have been widely used in optical communication and sensing, industrial processing, and solid laser pumping. However, semiconductor lasers also have the disadvantages of poor output beam quality, low spectral purity, and difficulty in achieving in-cavity regulation, which limits the further expansion of their application fields. External cavity semiconductor lasers combine the advantages of semiconductor lasers and solid-state lasers, using semiconductor materials as gain chips and combining external optical elements such as mirrors 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 the needs of a wider range of applications.

[0034] In order to improve the output power of the external cavity semiconductor laser, the external cavity semiconductor laser is often integrated into an array structure, including one-dimensional linear array and two-dimensional stacked array and surface array. However, the thermal effect of the external cavity semiconductor laser array seriously restricts the performance thereof. 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 the semiconductor material, the thermal resistance of the device is large, and the waste heat generated during work is difficult to dissipate from the active area of light emission and heat generation. Further, the external cavity semiconductor laser usually adopts air or solid medium as the external cavity, and the thermal conductivity of these materials is also low, and the heat cannot be extracted in time on the light-emitting side. For the external cavity semiconductor laser and the array thereof, the conventional heat dissipation mode is to transfer the heat to the substrate, and then dissipate the heat through the heat sink. This heat dissipation mode cannot meet the demand of the heat dissipation efficiency of the high-power external cavity semiconductor laser and the array thereof, and 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 of the array region is large, and the spectrum broadening and performance degradation problems, i.e. the thermal crosstalk problem, are caused.

[0035] In the process of implementing the present disclosure, the inventors found that at least the following problems exist in the related art: the conventional heat dissipation mode in the prior art cannot meet the heat dissipation demand of the external cavity semiconductor laser and the array thereof and the thermal crosstalk problem, and further limits the output power and power application of the external cavity semiconductor laser and the array thereof.

[0036] Based on this, the external cavity semiconductor laser array structure provided by the embodiments of the present disclosure solves the technical problem that the conventional heat dissipation mode cannot meet the heat dissipation demand of the external cavity semiconductor laser and the array thereof and the thermal crosstalk problem, and further limits the output power and power application of the external cavity semiconductor laser and the array thereof.

[0037] The structure comprises: a laser chip for providing optical gain; an external cavity mirror, which forms an external resonant cavity together with the laser chip, for providing optical feedback; and an external cavity cooling liquid filled between the laser chip and the external cavity mirror for absorbing the heat generated by the laser chip during work. The refractive index of the external cavity cooling liquid at the emission wavelength of the laser 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 embodiments of the present disclosure fills the cooling liquid as the external cavity medium between the laser chip and the external cavity mirror, cools the side of the laser chip close to the external cavity by using the cooling liquid, and combines the conventional semiconductor heat dissipation mode, so that the laser can realize omnidirectional and multi-angle heat dissipation, improve the working performance of the laser, and increase the reliability of the device.

[0039] According to an embodiment of the present disclosure, the laser chip can 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 emitting manner, 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 manner, that is, the light emitting direction of the laser is parallel to the substrate.

[0042] It should be understood that, regardless of surface emission or edge emission, the external cavity mirror is always arranged vertically to the light emitting direction.

[0043] To make the purpose, technical solutions and advantages of the present disclosure clearer, two embodiments (a first embodiment and a second embodiment) will be provided below for the vertical cavity surface emitting laser chip and the edge emitting laser chip respectively, and the present disclosure will be further described in detail with reference to the drawings.

[0044] First embodiment

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

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

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

[0048] The external cavity mirror 1 forms an external resonant cavity together with the vertical cavity surface emitting laser chip 3, and is configured to provide optical feedback, the external cavity mirror 1 being a medium having 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 mirror 1, and is configured to absorb 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 emission wavelength of the laser 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 the embodiment, the vertical cavity surface emitting laser chip 3 can specifically include a first substrate 31, a first distributed Bragg reflection layer 32 and an active region 33.

[0051] From Figure 1The first distributed Bragg reflection layer 32 is arranged on the first substrate 31 for providing optical feedback, and has a reflectivity at the laser emission wavelength greater than a first reflectivity threshold (which can be set to 99.5%, for example) to provide sufficient optical feedback.

[0052] The active region 33 is arranged on the first distributed Bragg reflection layer 32 for converting optical energy into photons under optical injection, and amplifying light intensity through stimulated emission to form optical gain.

[0053] In the embodiment, the vertical cavity surface emitting laser chip 3 can 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 arranged on the active region 33, and has a reflectivity at the laser emission wavelength less than the first reflectivity threshold, i.e. less than 99.5%, and preferably less than 50%.

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

[0056] The top electrode 6 is arranged at the top end of the second distributed Bragg reflection layer 34.

[0057] In the embodiment, the active region 33, the second distributed Bragg reflection layer 34 and the top electrode 6 are arranged in a two-dimensional periodic manner above the first distributed Bragg reflection layer 32.

[0058] The second distributed Bragg reflection layer 34 can form an internal resonant cavity together with the active region 33 and the first distributed Bragg reflection layer 32, and in combination with the bottom electrode 5 and the top electrode 6, can convert electrical energy into photons under electrical injection, and amplify light intensity through stimulated emission to form optical gain.

[0059] In the embodiment, the external cavity coolant 2 is filled in the external resonant cavity between the second distributed Bragg reflection layer 34 and the external cavity mirror 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 external cavity coolant 2 has a dielectric strength greater than 25 kV, i.e. has high electrical strength, so that the elements in the laser immersed in the external cavity coolant 2 will not be short-circuited, and the external cavity coolant 2 has an absorption less than 10 -4 cm -1 at the corresponding wavelength of the laser light emission, indicating that the absorption of the external cavity coolant 2 to the emitted light wave can be ignored.

[0061] In the present embodiment, the external cavity cooling liquid 2 can be configured in a first filling state (full filling) or a second filling state (partial filling).

[0062] In the full filling state, the external cavity cooling liquid 2 completely fills the external resonant cavity, leaving no gas space or no vacuum space in the external resonant cavity.

[0063] In the partial filling state, the external cavity cooling liquid 2 partially fills the external resonant cavity, leaving a certain gas space or vacuum space in the external resonant cavity. At this time, the length of the external resonant cavity can be changed accordingly, so that the overall cavity satisfies the resonance condition, forming laser output.

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

[0065] In the present embodiment, the external resonant cavity can also be configured to be able to improve the performance of the device by inserting optical elements, which will not be affected by the external cavity cooling liquid 2.

[0066] Second embodiment

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

[0068] As Figure 2 shown, the external cavity semiconductor laser array structure of the present embodiment includes an edge emitting laser chip 4, an external cavity mirror 1 and an external cavity cooling liquid 2.

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

[0070] The external cavity mirror 1 forms an external resonant cavity with the edge emitting laser chip 4 to provide optical feedback, and the external cavity mirror 1 is a medium with a certain reflectivity at the emission wavelength of the laser.

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

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

[0073] From Figure 2The gain region 42 is arranged on the second substrate 41 to provide optical gain.

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

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

[0076] The second cavity surface 422 is arranged at a position close to the external cavity mirror 1, and has a reflectivity less than the second reflectivity threshold (which can be less than 90%, and preferably less than 10%, or even completely transparent) at the laser emission wavelength, 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 mirror 1 form an external resonant cavity, and the distance between the front cavity surface and the external cavity mirror 1 is matched with the refractive index of the external cavity coolant 2 at the laser emission wavelength, so that the overall cavity satisfies 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] As Figure 3 In the external cavity semiconductor laser array structure of this embodiment, the edge-emitting laser chips 4 are arranged in one dimension in a 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 mirror 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, transparent, and low-absorption electrical insulating liquid at the laser emission wavelength, so that the laser is not short-circuited when 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 mode of a conventional heat sink, the gain region 42 and the second substrate 41 can be cooled in all directions and at multiple angles. Not only does this improve the heat dissipation efficiency and enhance the working performance of the device, but also greatly alleviates the thermal lens effect since the back cavity surface, the front cavity surface, and the external cavity mirror 1 are immersed in the external cavity coolant 2.

[0082] In this embodiment, the external cavity coolant 2 can be configured in a first filling state (full filling) or a second filling state (partial filling).

[0083] In the full filling state, the outer cavity coolant 2 completely fills the outer resonant cavity, so that there is no gas space or no vacuum space in the outer resonant cavity.

[0084] In the partial filling state, the outer cavity coolant 2 partially fills the outer resonant cavity, so that a certain gas space or vacuum space is reserved in the outer resonant cavity. At this time, the length of the outer resonant cavity can be changed accordingly, so that the overall cavity satisfies the resonance condition, and laser output is formed.

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

[0086] In this embodiment, the outer resonant cavity can also be configured to be able to improve the performance of the device by inserting optical elements, and the inserted optical elements will not be affected by the outer cavity coolant 2.

[0087] The flowcharts and block diagrams in the drawings illustrate the possible implementation architecture, function and operation of the system, method and computer program product according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram can represent a module, a program segment, or a part of code, which contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions noted in the blocks can occur in different order from that shown in the drawings. For example, two blocks represented in succession can actually be executed substantially in parallel, and sometimes they can be executed in reverse order, depending on the function involved. It should also be noted that each block in the block diagram or flowchart, and the combination of blocks in the block diagram or flowchart, can be implemented by a dedicated hardware-based system that performs the specified function or operation, or can be implemented by a combination of special-purpose hardware and computer instructions. Those skilled in the art can understand that the features described in various embodiments of the present disclosure can be combined and / or integrated in various combinations, even if such combinations or integrations are not explicitly described in the present disclosure. In particular, the features described in various embodiments of the present disclosure can be combined and / or integrated in various combinations without departing from the spirit and teachings of the present disclosure. All these combinations and / or integrations fall within the scope of the present disclosure.

[0088] The above describes embodiments of the present disclosure. However, these embodiments are merely for illustrative purposes, and are not intended to limit the scope of the present disclosure. Although each embodiment is described above separately, this does not mean that the measures in each embodiment cannot be used advantageously in combination. Those skilled in the art can make various substitutions and modifications without departing from the scope of the present disclosure, and these substitutions and modifications should all fall within the scope of the present disclosure.

Claims

1. An external cavity semiconductor laser array structure, characterized in that: The structure includes: Laser chip, 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; External cavity coolant, filled between the laser chip and the external cavity reflector, for absorbing 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 includes: a first substrate; a first distributed Bragg reflector layer, disposed on the first substrate and configured to provide optical feedback, wherein a reflectivity of the first distributed Bragg reflector layer at a laser emission wavelength is greater than a first reflectivity threshold; The active region is provided on the first distributed Bragg reflector layer and is used for converting light energy into photons under light injection, amplifying light intensity by stimulated emission, and forming optical gain.

3. The structure according to claim 2, characterized in that The vertical cavity surface emitting laser chip further includes: a second distributed Bragg reflector layer, disposed on the active region, wherein a reflectivity of the second distributed Bragg reflector 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 emission 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 is provided on the second substrate and is used to provide optical gain, wherein the gain region includes: a first cavity facet, provided at an end away from the external cavity reflector, wherein a reflectivity of the first cavity facet 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 reflector, 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 further comprises: a bottom electrode, provided 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 absorption 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.

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