Solid laser with heat effect reducing structure

Abstract

The invention discloses a solid laser with a heat effect reducing structure, and relates to the technical field of lasers, the solid laser comprises a laser gain medium, a pump light source and a heat management module, the laser gain medium is arranged in a laser resonant cavity formed by at least one reflector, the pump light source is used for exciting the laser gain medium, and the heat management module is used for controlling the heat effect reducing structure. The heat management module comprises a heat conduction substrate, a plurality of micro-channel cooling structures arranged in parallel along the interior of the heat conduction substrate, a heat diffusion layer and a heat interface material. By installing the rectangular micro-channel cooling structure, local heat generated by the laser gain medium is efficiently absorbed and conducted, uniform cooling is achieved, local overheating, hot plate and thermal lens effects are effectively prevented, optical distortion and device deformation caused by thermal gradient on the surface are avoided, the overall thermal management efficiency is improved, and the service life of the laser is prolonged. The laser is ensured to work stably under a high-power operation condition, the service life of the device is prolonged, and the output beam quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of lasers, in particular to a solid laser with a thermal effect reduction structure. Background Art

[0002] At present, high-power solid-state lasers generally face thermal effect problems in practical applications. As the laser power continues to increase, the laser gain medium will generate a lot of heat while absorbing the pump light energy, causing the local temperature to rise sharply, thus causing problems such as thermal lens effect, local hot spots and device deformation.

[0003] These thermal effects will not only reduce the quality of the laser output beam, but may also lead to a decrease in the overall stability of the laser and a shortened service life. Traditional air-cooling or water-cooling systems often have difficulty achieving efficient and uniform heat conduction and heat dissipation when faced with high-density heat loads, especially in local hot spots, where the heat dissipation effect is greatly reduced.

[0004] Patent document CN102513693B discloses a high-power fiber laser welding machine. The above patent improves the light-to-light conversion rate and output power, avoids thermal effects, nonlinear effects caused by strong laser single points, and mode deterioration, is suitable for heat dissipation of the pump source and improves service life.

[0005] In summary, the above patent solves the problem of reducing the thermal effect of the coupling node in the fiber laser welding process through the coupled double-clad optical fiber, the robotic arm and the pure fiber-coupled fiber laser obtained by segmented reward, improves the output power, and clarifies the number of segmented couplings and the optimal coupling distance. However, there is still room for optimization on the thermal effect problem existing in the laser. To this end, the present application proposes a solid-state laser with a thermal effect reduction structure that can efficiently absorb and conduct local heat generated by a laser gain medium and achieve uniform cooling. Summary of the invention

[0006] The purpose of the present invention is to provide a solid laser with a thermal effect reduction structure to solve the technical problems proposed in the above background technology that the laser gain medium will generate a large amount of heat while absorbing pump light energy, causing the local temperature to rise sharply, thereby causing thermal lens effect, local hot spots and device deformation.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a solid-state laser with a thermal effect reduction structure, comprising a laser gain medium, a pump light source and a thermal management module, wherein the laser gain medium is arranged in a laser resonant cavity formed by at least one reflector, the pump light source is used to excite the laser gain medium, and the thermal management module comprises: a thermal conductive substrate, a plurality of microchannel cooling structures arranged in parallel along the inside of the thermal conductive substrate, a thermal diffusion layer and a thermal interface material, and each component in the thermal management module is combined into an integral structure by a mechanical snap-fit ​​fixing method; The heat conduction substrate is made of a material with high thermal conductivity. The microchannel cooling structure is designed to have a rectangular cross-section, and the width and depth are optimized according to the heat distribution generated by the laser gain medium. The heat diffusion layer is connected to the heat conduction substrate structure to quickly diffuse the local high temperature to the whole and reduce the temperature gradient. The thermal interface material is located between the laser gain medium and the heat conduction substrate to firmly thermally couple the laser gain medium and the heat conduction substrate. One end of the microchannel cooling structure is connected to an external coolant fluid channel to form a closed cooling circulation system to absorb and conduct the heat generated by the laser gain medium, thereby reducing the thermal effect.

[0008] Preferably, the gain medium is in the shape of a cube, selected from Nd:YAG, Yb:YAG or Cr:LiCAF materials, with each side length of 15 mm, the output end of the pump light source is coupled to the laser gain medium through an optical fiber with a diameter of 1 mm and a length of 10 mm, and the reflector is a plane reflector with a diameter of 50 mm and a reflective coating with a thickness of 150 nm on the surface.

[0009] Preferably, the heat conduction substrate is a rectangular plate structure, made of copper or diamond material, the surface of the heat conduction substrate is treated with chemical copper plating, and the average surface roughness Ra is less than 0.3um. The heat diffusion layer is a thin sheet structure, supported by alumina ceramic material, with a thickness of 0.5mm, and the surface is designed with a periodic micro-concave structure formed by an etching process, with a groove spacing of 1mm, a groove width of 0.3mm, and a groove depth of 0.2mm. The thermal interface material is a high thermal conductivity thermal conductive glue, a copper-based composite material or a metal thermal conductive gasket.

[0010] Preferably, the microchannel cooling structure is modular in design, each module has a size of 30 mm×30 mm, at least 5 microchannels are provided in the module, and the modules are fixed by mechanical snap connections.

[0011] Preferably, the laser gain medium is mounted on a metal bracket, on which a temperature sensor and a feedback control circuit are provided. The temperature sensor and the feedback control circuit are used to monitor the temperature of the laser gain medium in real time and automatically adjust the flow rate of the coolant according to the monitoring results. The temperature sensor is a packaged thermistor with a size of 3mm×3mm×1mm, and the feedback control circuit includes a microprocessor and an analog-to-digital conversion module.

[0012] Preferably, the laser resonant cavity is composed of an input reflector and an output reflector, and both the input reflector and the output reflector are fixed on a bracket made of aluminum alloy.

[0013] Preferably, an adaptive optical element is further arranged in the laser resonant cavity, and the adaptive optical element includes: a deformable mirror, a plurality of piezoelectric ceramic valve drivers distributed on the back side of the deformable mirror, and a fixed bracket. The deformable mirror has a diameter of 30 mm and a thickness of 3 mm. The material is a lightweight aluminum alloy, and the surface is mechanically polished. The size of each piezoelectric ceramic valve driver is 5 mm×5 mm×1 mm, and they are evenly arranged along the periphery of the deformable mirror with a center spacing of 10 mm. The thickness of the fixed bracket is 1 mm, and the deformable mirror is fixed to the fixed bracket by screws.

[0014] Preferably, the coolant in the cooling circulation system is selected from deionized water, ethylene glycol or a deionized water-ethylene glycol mixture, and the mixing ratio of the deionized water-ethylene glycol mixture is limited to a range of 10:1 to 1:1.

[0015] Preferably, the cooling circulation system further comprises a liquid inlet pipe and a liquid outlet pipe, both of which are metal pipes with an inner diameter of 2 mm and a length of 50 mm, and the inner walls of the pipes are polished.

[0016] Preferably, the cooling circulation system also includes a porous distribution plate for connecting the pipelines. The hole diameter of the porous distribution plate is 0.5±0.05mm, the hole spacing is 1.0±0.1mm, and it is CNC machined and treated with an anti-deposition coating. The pipelines and the porous distribution plate are fixed to the microchannel interface using M3 threaded connections.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention is equipped with a rectangular microchannel cooling structure to efficiently absorb and conduct the local heat generated by the laser gain medium, achieve uniform cooling, effectively prevent local overheating, hot plate and thermal lens effects, thereby reducing optical distortion and device deformation caused by thermal gradients on the surface, improving the overall thermal management efficiency, ensuring that the laser maintains stable operation under high-power operating conditions, extending the device life and improving the output beam quality; 2. The present invention is equipped with a heat diffusion layer and a thermal interface material to quickly diffuse the high temperature generated locally by the laser gain medium to the entire heat conduction substrate, thereby achieving a uniform temperature effect, reducing the local temperature gradient, alleviating the thermal stress and thermal lens phenomenon caused by local high temperature, and achieving rapid and uniform distribution of heat, thereby ensuring the temperature stability of the newspaper laser during operation, and thus maintaining excellent optical properties; 3. The present invention is equipped with a temperature sensor and a feedback control circuit to monitor the temperature of the laser gain medium in real time, and automatically adjust the flow rate of the coolant according to the temperature data to prevent the laser gain medium from abnormally rising in temperature due to heat accumulation, ensure that the temperature is controlled within the design range, avoid overheating, and provide a dynamic adjustment mechanism so that the cooling system can respond quickly according to the actual heat load changes, thereby ensuring the stable operation and long-term reliability of the laser; 4. The present invention installs adaptive optical elements to adjust the shape of the deformable mirror in real time, dynamically compensates the laser beam wavefront, effectively eliminates optical distortion and wavefront distortion caused by thermal effects or mechanical stress, ensures the stability of the optical path in the laser resonant cavity, improves the quality and stability of the laser output beam, and enables high-power lasers to maintain high-precision and high-efficiency laser output under harsh working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the internal structure of the laser of the present invention; Figure 2 It is a schematic diagram of the microchannel cooling structure of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] See also Figure 1 and Figure 2 , an embodiment provided by the present invention: a solid laser with a thermal effect reduction structure, comprising a laser gain medium, a pump light source and a thermal management module, wherein the laser gain medium is arranged in a laser resonant cavity formed by at least one reflector, the pump light source is used to excite the laser gain medium, the thermal management module comprises: a thermal conductive substrate, a plurality of microchannel cooling structures arranged in parallel along the interior of the thermal conductive substrate, a heat diffusion layer and a thermal interface material, and each component in the thermal management module is combined into an integral structure by a mechanical snap-fit ​​fixing method; The heat conduction substrate is made of a high thermal conductivity material. The microchannel cooling structure is designed to be a rectangular cross-section, and the width and depth are optimized according to the heat distribution generated by the laser gain medium. The heat diffusion layer is connected to the heat conduction substrate structure to quickly diffuse the local high temperature to the whole and reduce the temperature gradient. The thermal interface material is located between the laser gain medium and the heat conduction substrate to firmly thermally couple the laser gain medium and the heat conduction substrate. One end of the microchannel cooling structure is connected to an external coolant fluid channel to form a closed cooling circulation system to absorb and conduct the heat generated by the laser gain medium, thereby reducing the thermal effect. Furthermore, the laser gain medium is made of Nd:YAG material, and has a cubic shape with a side length of 15 mm. Each surface is plane-finely ground and polished to ensure that Ra is less than or equal to 0.2 um. The pump light source is aligned with the incident end face of the laser gain medium through a single-mode optical fiber with a diameter of 1 mm and a length of 100 mm. The laser gain medium is placed in a laser resonant cavity formed by at least one reflecting mirror. The pump light excites the gain medium to generate laser output. At the same time, the laser gain medium generates heat in the process of absorbing light energy. When the pump light source excites the laser gain medium, the laser output forms oscillation in the resonant cavity. At the same time, the laser gain medium generates heat in the process of absorbing light energy. The heat absorbs part of the light energy and generates heat, which is first conducted to the heat conduction substrate through the contact surface between the laser gain medium and the thermal interface material. Inside the heat conduction substrate, the coolant in the rectangular microchannel cooling structure circulates along the preset flow direction, absorbs and takes away the local heat along the inner wall of the channel; at the same time, the heat diffusion layer is connected to the heat conduction substrate, which quickly diffuses the locally generated high temperature to the entire substrate area, reducing the local temperature difference. The entire thermal management module uses mechanical buckles to achieve overall fixation of various components, ensuring that each interface and contact surface has high precision and stability, thus forming an efficient closed cooling circulation system; A rectangular channel with optimized size is formed inside the heat conduction substrate through CNC machining, and the layout is carried out according to the heat distribution of the laser gain medium, which solves the problems of uneven local heat dissipation and low cooling efficiency in the traditional cooling structure, realizes uniform absorption and conduction of heat in the entire substrate, and effectively prevents the formation of local hot spots; the heat diffusion layer diffuses the local high temperature to the whole through the periodic micro-concave structure design, and the thermal interface material realizes the firm thermal coupling between the laser gain medium and the heat conduction substrate through the predetermined groove and buckle structure, which solves the problems of excessive thermal gradient, thermal lens effect and thermal deformation caused by local heat concentration of the laser gain medium, reduces the temperature gradient, ensures the uniformity of overall heat transfer, and improves the operating stability of the laser at high power; a standardized interface is provided at one end of the microchannel, using M3 thread and sealing O-ring to achieve seamless connection with the external coolant fluid channel, solves the problems of interface leakage and unstable coolant circulation in the traditional cooling system, and forms a stable and reliable closed cooling circulation system to ensure that the heat generated by the laser gain medium can be continuously and efficiently conducted out.

[0023] See also Figure 1 and Figure 2 , an embodiment provided by the present invention: a solid laser with a structure for reducing thermal effects, wherein the gain medium is in the shape of a cube, selected from Nd:YAG, Yb:YAG or Cr:LiCAF materials, each side of which is 15 mm in length, the output end of the pump light source is coupled to the laser gain medium through an optical fiber with a diameter of 1 mm and a length of 10 mm, the reflector is a plane reflector with a diameter of 50 mm and a reflective coating with a thickness of 150 nm on the surface; The heat conduction substrate is a rectangular plate structure, made of copper or diamond material, the surface of the heat conduction substrate is treated with chemical copper plating, and the average surface roughness Ra is less than 0.3um, the heat diffusion layer is a thin sheet structure, supported by alumina ceramic material, with a thickness of 0.5mm, and the surface is designed with a periodic micro-concave structure formed by an etching process, with a groove spacing of 1mm, a groove width of 0.3mm, and a groove depth of 0.2mm. The thermal interface material is a high thermal conductivity thermal conductive glue, a copper-based composite material or a metal thermal conductive pad; The microchannel cooling structure is modular in design. Each module has a size of 30 mm × 30 mm. At least 5 microchannels are arranged in the module, and the modules are fixed by mechanical buckle connection. Furthermore, Nd:YAG material is selected to manufacture the cube, and each side thereof is processed to 15 mm. Precision plane grinding and polishing processes are used during the processing to make it Ra≤0.2 um. The laser gain medium is pre-processed with alignment holes for positioning to ensure accurate installation in the laser resonant cavity. The output end of the pump light source is equipped with a single-mode optical fiber with a core diameter of 1 mm and a total length of 10 mm. The end face of the optical fiber is laser cut and mechanically polished to ensure the flatness and finish of the end face to achieve high-precision optical coupling. The optical fiber and the laser gain medium are fixed by a customized mechanical interface to ensure that the end faces of the optical fiber and the gain medium are aligned and stably bonded. A 50mm diameter plane reflector is used. The substrate is high-purity silicon glass. The reflector surface is ion-plated and evenly coated with a 150nm thick reflective coating. The coating uniformity error is controlled within ±5%. The reflector is installed on a precision positioning bracket, and the bracket is stably connected to other components of the resonant cavity through customized threaded holes. The micro-concave structure on the surface of the heat diffusion layer helps to achieve uniform diffusion of local heat during heat conduction, and quickly transfers local high temperature to the entire heat conduction substrate area; The microchannel modular design is interconnected and fixed through a customized mechanical buckle structure. The buckle design ensures that the relative position accuracy between modules is controlled within ±0.02mm. The buckle connection adopts a seismic design, which not only ensures stability in long-term operation, but also facilitates future maintenance and replacement. The laser gain medium, pump light source and reflector constitute the laser resonant cavity. The laser forms oscillation after multiple reflections in the resonant cavity. At the same time, the laser gain medium generates heat in the process of absorbing the pump light. The generated heat is transferred to the heat conduction substrate through the direct contact between the laser gain medium and the thermal interface material, and then quickly taken away by the modular microchannel cooling structure inside the heat conduction substrate. The heat diffusion layer evenly distributes the local high temperature of the heat conduction substrate to the entire heat conduction substrate to prevent thermal gradient problems caused by local processes. The closed coolant circulation system ensures that the coolant continues to flow inside the system, effectively realizing the rapid transfer and dissipation of heat.

[0024] See also Figure 1 and Figure 2 , an embodiment provided by the present invention: a solid laser with a thermal effect reduction structure, the laser gain medium is installed on a metal bracket, a temperature sensor and a feedback control circuit are arranged on the metal bracket, the temperature sensor and the feedback control circuit are used to monitor the temperature of the laser gain medium in real time, and automatically adjust the flow rate of the coolant according to the monitoring result, the temperature sensor is a packaged thermistor with a size of 3mm×3mm×1mm, and the feedback control circuit includes a microprocessor and an analog-to-digital conversion module; The laser resonant cavity is composed of an input reflector and an output reflector, and the input reflector and the output reflector are both fixed on a bracket made of aluminum alloy; Furthermore, the laser gain medium is fixedly installed on a special metal bracket, which is made of high-temperature resistant metal material. The metal bracket is provided with positioning grooves and bayonet for installing the laser gain medium to ensure that the contact surface between the gain medium and the bracket is uniform and tight. The metal bracket is provided with a specially reserved installation area for fixing the temperature sensor and the feedback control circuit to facilitate the collection of temperature data around the laser gain medium and data transmission; the temperature sensor is installed closely next to the laser gain medium through a customized bayonet to ensure that the heat information generated by the medium can be accurately collected, and the temperature sensor and the metal bracket are filled with thermal conductive paste to reduce the interface thermal resistance; the feedback control circuit is fixedly installed on the other side of the metal bracket, and a microprocessor and an analog-to-digital conversion module are integrated on the circuit board. The analog signal output by the temperature sensor is transmitted to the analog-to-digital conversion module through a special shielded cable, and is processed by the microprocessor after sampling and conversion. The microprocessor drives the coolant flow regulation module such as an electronic proportional valve through a digital output signal according to a preset temperature threshold and algorithm to achieve automatic adjustment of the coolant flow.

[0025] See also Figure 1 and Figure 2 , an embodiment provided by the present invention: a solid laser with a thermal effect reduction structure, wherein an adaptive optical element is further arranged in the laser resonant cavity, the adaptive optical element comprising: a deformable mirror, a plurality of piezoelectric ceramic valve drivers distributed on the back side of the deformable mirror, and a fixed bracket, the deformable mirror has a diameter of 30 mm and a thickness of 3 mm, and is made of a lightweight aluminum alloy, and the surface is mechanically polished, each piezoelectric ceramic valve driver has a size of 5 mm×5 mm×1 mm, and is evenly arranged along the periphery of the deformable mirror, with a center spacing of 10 mm, and a fixed bracket with a thickness of 1 mm, and the deformable mirror is fixed to the fixed bracket by screws; Furthermore, the deformable mirror is pre-processed with a number of positioning holes for subsequent screw connection with the fixing bracket, and is fixed to the fixing bracket by high-precision screws to ensure that the mirror position and angle accuracy after installation meet the requirements of the optical system. The piezoelectric ceramic drivers are evenly arranged along the periphery of the back side of the deformable mirror, and the arrangement method is circumferentially uniform. The center spacing of the piezoelectric ceramic drivers is positioned at 10mm to ensure that the piezoelectric ceramic drivers are evenly distributed and can achieve precise control of the local area of ​​the mirror. The piezoelectric ceramic drivers are fixed to the back side of the deformable mirror by a special conductive adhesive, which ensures both firm mechanical bonding and good electrical performance. The fixing bracket is pre-processed with mounting holes that match the positioning holes of the deformable mirror to ensure that the deformable mirror can be accurately positioned during the assembly process, and has high shock and temperature resistance. The deformable mirror is fixed to the fixing bracket by screws, and all connecting parts are pre-tightened to ensure that there is no looseness during the assembly process. The screw fixing points are symmetrically arranged along the edge of the deformable mirror, and the distribution is reasonable to reduce the stress concentration caused by uneven installation. The fixing bracket is installed in the same way as other optical components inside the laser resonator, and is installed using standardized interfaces and precision positioning pins to ensure the stability of the overall system; The assembled adaptive optical element is fixed at the predetermined position in the laser resonant cavity to ensure the optical path matching between the input and output reflectors. During the integration process, the deformable mirror is preliminarily calibrated using a laser collimator and an interferometer to detect its initial flatness and assembly error. After receiving an external control signal, each piezoelectric ceramic driver is driven by a feedback control system to achieve fine-tuning of the deformable mirror. The piezoelectric ceramic driver is corrected in real time using a wavefront sensor and a closed-loop control algorithm, so that the deformable mirror can actively compensate for optical distortion under control to meet the system design requirements. The uniform arrangement and precise positioning of the piezoelectric ceramic driver achieve uniform control of the local deformation of the mirror and improve the response speed and accuracy of the adaptive adjustment. Through adaptive optical elements, the optical distortion caused by thermal effects or mechanical stress in the laser resonant cavity can be corrected in real time, thereby improving the beam quality of the laser output.

[0026] See also Figure 1 and Figure 2 , an embodiment provided by the present invention: a solid laser with a thermal effect reduction structure, the coolant in the cooling circulation system is selected from deionized water, ethylene glycol or a deionized water ethylene glycol mixture, and the mixing ratio of the deionized water ethylene glycol mixture is limited to the range of 10:1 to 1:1; The cooling circulation system also includes a liquid inlet pipe and a liquid outlet pipe, both of which are metal pipes with an inner diameter of 2 mm and a length of 50 mm, and the inner wall of the pipe is polished; The cooling circulation system also includes a porous distribution plate for connecting various pipelines. The aperture of the porous distribution plate is 0.5±0.05mm, the hole spacing is 1.0±0.1mm, and it is CNC machined and treated with an anti-deposition coating. The pipeline and the porous distribution plate are fixed to the microchannel interface by M3 threaded connection. Furthermore, a mixture of deionized water and ethylene glycol with a mixing ratio of 5:1 is selected, and the liquid inlet pipe and the liquid outlet pipe are both made of metal pipes, and stainless steel materials with excellent corrosion resistance and thermal conductivity are selected. The inner wall of the pipe is surface-finished by a mechanical polishing process to ensure that the inner wall is smooth within the range of Ra≤0.15um, thereby reducing fluid resistance and sediment adhesion; The porous distribution plate is used to connect various pipelines and evenly distribute the coolant to multiple microchannels to improve the overall heat dissipation efficiency. After the porous distribution plate is processed, it is treated with an anti-deposition coating, which can prevent impurities in the coolant from depositing on the plate surface, keeping the channels unobstructed and stable for a long time. The pipeline and the porous distribution plate are fixedly connected with standardized M3 threaded interfaces. O-type rubber sealing rings can be pre-installed at the M3 threaded connections to further improve the sealing performance of the interface. After assembly, inject the pre-prepared mixture of deionized water and ethylene glycol into the closed cooling circulation system, and conduct a system sealing test. Perform flow, pressure and temperature tests on the system to ensure that the coolant is evenly distributed in each pipeline and porous distribution plate. At the same time, verify the effect of internal polishing and anti-deposition coating to ensure that there is no blockage or leakage during long-term operation.

[0027] Working principle: The pump light source transmits laser light into the laser gain medium placed in the laser resonant cavity through a single-mode optical fiber. After absorbing the pump light energy, the laser gain medium generates stimulated radiation to form laser oscillation. At the same time, since part of the light energy is converted into heat energy, heat is generated inside the laser gain medium. The laser gain medium is firmly coupled with the heat-conducting substrate through the pre-set thermal interface material. The rectangular microchannel cooling structure and heat diffusion layer integrated in the heat-conducting substrate use the precisely designed size and surface micro-concave structure to quickly dissipate the local high temperature generated by the laser gain medium and diffuse it evenly in the heat-conducting substrate, thereby reducing the local temperature difference and thermal gradient, and alleviating the thermal lens effect and structural deformation caused by local overheating. Through the standardized M3 threaded interface connected to the microchannel cooling structure, the coolant forms a closed circulation system in the inlet and outlet pipes with an inner diameter of 2 mm. The system is equipped with a temperature sensor and feedback control circuit to monitor the temperature of the laser gain medium in real time, and automatically adjust the coolant flow rate according to the temperature data to ensure that the entire thermal management module can efficiently and continuously remove heat, thereby maintaining the working stability and beam quality of the laser.

[0028] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A solid laser with a thermal effect reduction structure, comprising a laser gain medium, a pump light source and a thermal management module, characterized in that: The laser gain medium is arranged in a laser resonant cavity formed by at least one reflector, the pump light source is used to excite the laser gain medium, the thermal management module comprises: a thermal conductive substrate, a plurality of microchannel cooling structures arranged in parallel along the inside of the thermal conductive substrate, a thermal diffusion layer and a thermal interface material, and the components in the thermal management module are combined into an integral structure by mechanical buckle fixing; The heat conduction substrate is made of a material with high thermal conductivity. The microchannel cooling structure is designed to have a rectangular cross-section, and the width and depth are optimized according to the heat distribution generated by the laser gain medium. The heat diffusion layer is connected to the heat conduction substrate structure to quickly diffuse the local high temperature to the whole and reduce the temperature gradient. The thermal interface material is located between the laser gain medium and the heat conduction substrate to firmly thermally couple the laser gain medium and the heat conduction substrate. One end of the microchannel cooling structure is connected to an external coolant fluid channel to form a closed cooling circulation system to absorb and conduct the heat generated by the laser gain medium, thereby reducing the thermal effect.

2. The solid-state laser with a thermal effect reduction structure according to claim 1, characterized in that: The gain medium is in the shape of a cube, selected from Nd:YAG, Yb:YAG or Cr:LiCAF materials, with each side length of 15 mm. The output end of the pump light source is coupled to the laser gain medium through an optical fiber with a diameter of 1 mm and a length of 10 mm. The reflector is a plane reflector with a diameter of 50 mm and a reflective coating with a thickness of 150 nm on the surface.

3. The solid-state laser with a thermal effect reduction structure according to claim 1, characterized in that: The heat conduction substrate is a rectangular plate structure, made of copper or diamond material, the surface of the heat conduction substrate is treated with chemical copper plating, and the average surface roughness Ra is less than 0.3um. The heat diffusion layer is a thin sheet structure, supported by alumina ceramic material, with a thickness of 0.5mm. The surface is designed with a periodic micro-concave structure formed by an etching process, with a groove spacing of 1mm, a groove width of 0.3mm, and a groove depth of 0.2mm. The thermal interface material is a high thermal conductivity thermal conductive adhesive, a copper-based composite material or a metal thermal conductive gasket.

4. The solid-state laser with a thermal effect reduction structure according to claim 1, characterized in that: The microchannel cooling structure is modular in design. Each module has a size of 30 mm×30 mm. At least 5 microchannels are arranged in the module, and the modules are fixed by mechanical snap connections.

5. The solid-state laser with a thermal effect reduction structure according to claim 1, characterized in that: The laser gain medium is installed on a metal bracket, on which a temperature sensor and a feedback control circuit are arranged. The temperature sensor and the feedback control circuit are used to monitor the temperature of the laser gain medium in real time and automatically adjust the flow rate of the coolant according to the monitoring result. The temperature sensor is a packaged thermistor with a size of 3mm×3mm×1mm, and the feedback control circuit includes a microprocessor and an analog-to-digital conversion module.

6. The solid-state laser with a thermal effect reduction structure according to claim 1, characterized in that: The laser resonant cavity is composed of an input reflector and an output reflector, and both the input reflector and the output reflector are fixed on a bracket made of aluminum alloy.

7. The solid-state laser with a thermal effect reduction structure according to claim 1, characterized in that: An adaptive optical element is further arranged in the laser resonant cavity, and the adaptive optical element includes: a deformable mirror, a plurality of piezoelectric ceramic valve drivers distributed on the back side of the deformable mirror, and a fixed bracket. The deformable mirror has a diameter of 30 mm and a thickness of 3 mm. The material is a lightweight aluminum alloy, and the surface is mechanically polished. The size of each piezoelectric ceramic valve driver is 5 mm×5 mm×1 mm, and they are evenly arranged along the periphery of the deformable mirror with a center spacing of 10 mm. The fixed bracket has a thickness of 1 mm, and the deformable mirror is fixed to the fixed bracket by screws.

8. The solid-state laser with a thermal effect reduction structure according to claim 1, characterized in that: The coolant in the cooling circulation system is selected from deionized water, ethylene glycol or a deionized water-ethylene glycol mixture, and the mixing ratio of the deionized water-ethylene glycol mixture is limited to a range of 10:1 to 1:

1.

9. The solid-state laser with a thermal effect reduction structure according to claim 1, characterized in that: The cooling circulation system also includes a liquid inlet pipe and a liquid outlet pipe, both of which are metal pipes with an inner diameter of 2 mm and a length of 50 mm, and the inner walls of the pipes are polished.

10. The solid-state laser with a thermal effect reduction structure according to claim 1, characterized in that: The cooling circulation system also includes a porous distribution plate for connecting various pipelines. The hole diameter of the porous distribution plate is 0.5±0.05mm, the hole spacing is 1.0±0.1mm, it is CNC machined and treated with an anti-deposition coating, and the pipelines and the porous distribution plate are fixed to the microchannel interface using M3 threaded connections.

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