Micro-channel water cooling module for four-pass slab laser amplification system

Abstract

The invention discloses a micro-channel water cooling module for a four-pass slab laser amplification system, relates to the technical field of laser heat dissipation, and solves the problems that in the prior art, temperature measurement is inaccurate, and the interior of a liquid cooling structure is closed and cannot be overhauled. The device comprises a base body, two micro-channel heat dissipation blocks are detachably arranged on the base body in parallel, a gap between the two micro-channel heat dissipation blocks is used for arranging a lath laser crystal, a temperature detection unit used for being matched with the lath laser crystal is arranged on the base body, and a shading structure used for being matched with the temperature detection unit is arranged on the base body; heat sink liquid inlet and outlet blocks are detachably arranged on the outer sides of the micro-channel heat dissipation blocks, liquid inlet and outlet structures are arranged on the heat sink liquid inlet and outlet blocks, and the liquid inlet and outlet structures are connected with heat exchange structures arranged on the micro-channel heat dissipation blocks. The micro-channel heat dissipation blocks are arranged in parallel, and the shading structure is arranged in the gap between the micro-channel heat dissipation blocks, so that the temperature monitoring unit can be prevented from absorbing pump light, and the temperature measurement error is reduced; meanwhile, the components are detachably connected, so that disassembly and assembly are convenient.

Description

Technical Field

[0001] The invention relates to the technical field of laser heat dissipation, and in particular to a microchannel water cooling module for a four-pass slab laser amplification system. Background Art

[0002] Diode-pumped solid-state lasers have many advantages such as high efficiency, small size, and good output beam quality, and have been widely used in the fields of industry, scientific research, military, and medical treatment. Compared with diode side-pumped solid-state lasers, the thermal effect of the laser medium is more serious. This is because in end-pumped solid-state lasers, the pump light is concentrated in a very small area within the laser crystal, and the beam waist diameter is generally less than 1mm. Its power density is much higher than that of side-pumped solid-state lasers. The high power density inevitably leads to a large amount of waste heat accumulating in a very small area. If the waste heat cannot be removed in a timely and efficient manner, it will cause more serious thermal effect problems.

[0003] Traditional heat dissipation methods include large channel circulating water cooling or semiconductor refrigeration. These two cooling methods have their own advantages and disadvantages. When building a solid laser, they can improve the impact of thermal effects on the laser crystal. As the laser power increases, it becomes increasingly difficult to meet the heat dissipation needs of the laser. At the same time, it will also cause problems such as uneven temperature distribution inside the laser crystal, leading to serious thermal effect problems. The traditional microchannel heat sink uses a welding method to weld the microchannel layer and the water inlet layer together. When the microchannel layer is blocked, it cannot be effectively cleaned. In addition, the temperature measurement of the crystal has always been a major engineering problem, because the thermocouple probe may interfere with the laser beam, and the thermocouple may leave scratches on the crystal surface when it contacts it. Even if the temperature is measured, the temperature is inaccurate due to the strong infrared radiation of the fluorescence.

[0004] The Chinese utility model patent with publication number CN218569487U discloses a laser crystal temperature control device. A laser crystal temperature control device crystal cooling seat, the top surface of which is provided with an inwardly concave cooling groove; a circulating water circuit, which is connected to the cooling groove, and the circulating water circuit is provided with a speed regulating valve for adjusting the water flow speed; a laser crystal fixture, the bottom surface of which is connected to the crystal cooling seat and covers the cooling groove. The present application discloses a laser crystal temperature control device, in which a speed regulating valve for adjusting the water flow speed is provided on the circulating water circuit. The speed of the water flow is adjusted by the speed regulating valve according to different heat dissipation requirements. The water flow in the cooling groove will contact the bottom surface of the laser crystal fixture during the flow process. The cooling water exchanges heat with the laser crystal fixture in the circulating water circuit, and quickly takes away the waste heat generated during the operation of the laser crystal.

[0005] In this scheme, the laser crystal is mainly clamped and fixed and heat-conducted by the laser crystal clamp. The heat obtained by the clamp is directly exchanged with the water in the cooling tank through the bottom surface. However, the bottom surface is only a flat structure with limited contact area and one-sided heat dissipation. Therefore, the heat transfer capacity is limited, and poor heat dissipation is prone to occur when the heat generation is large.

[0006] Secondly, in order to accurately measure the real-time temperature of the laser crystal, it is generally necessary to place the temperature sensor close to the laser crystal, or to set the temperature sensor on a fixture for temperature measurement. When placed close together, the thermistor is irradiated by the pump light in the optical path, thereby absorbing additional heat, resulting in inaccurate temperature measurement. The thermistor is installed in the fixture, which is actually still some distance away from the laser crystal and cannot reflect the accurate temperature of the laser crystal in real time. Summary of the invention

[0007] In view of the deficiencies in the above-mentioned background technology, the present invention proposes a microchannel water cooling module for a four-pass slab laser amplification system, which solves the problems of inaccurate temperature measurement and limited heat dissipation capacity in the prior art.

[0008] The technical solution of the present invention is achieved as follows: a microchannel water cooling module for a four-pass slab laser amplification system comprises a substrate, two microchannel heat sinks are detachably provided in parallel on the substrate, the gap between the two microchannel heat sinks is used to set a slab laser crystal, a temperature detection unit for cooperating with the slab laser crystal is provided on the substrate, and a shading structure for cooperating with the temperature monitoring unit is provided on the substrate; a heat sink inlet and outlet liquid block is detachably provided on the outer side of the microchannel heat sink, a liquid inlet and outlet structure is provided on the heat sink inlet and outlet liquid block, and the liquid inlet and outlet structure is connected to a heat exchange structure provided on the microchannel heat sink.

[0009] Preferably, the base includes two parallel and correspondingly arranged heat sink fixing plates, and a plurality of long waist holes are opened on the heat sink fixing plates. The heat sink fixing plates and the microchannel heat sink block and / or the heat sink fixing plates and the heat sink inlet and outlet blocks are connected by bolts passing through the long waist holes.

[0010] Preferably, at least one through hole is formed on the heat sink fixing plate, and the light shielding structure comprises baffles fixedly arranged on both sides of the through hole along the length direction.

[0011] Preferably, the microchannel heat dissipation block is connected to the heat sink inlet and outlet block by bolts, and the slab laser crystal is fixed to the microchannel heat dissipation block by indium welding.

[0012] Preferably, the heat exchange structure comprises strip-shaped microchannels opened in parallel on the microchannel heat sink block, and adjacent microchannels are separated by fins. The microchannels are opened along the length direction of the slab laser crystal.

[0013] Preferably, the liquid inlet and outlet structure comprises a liquid inlet and a liquid outlet opened on the heat sink liquid inlet and outlet block along the length direction of the slab laser crystal. The liquid inlets are arranged in pairs and are respectively located on both sides of the liquid outlet.

[0014] Preferably, the liquid inlet and the liquid outlet both include a connected rectangular hole segment and a circular hole segment, the rectangular hole segment is arranged on the inner side of the heat sink liquid inlet and outlet block, and the circular hole segment is arranged on the outer side of the heat sink liquid inlet and outlet block, the rectangular hole segment is used to cooperate with a plurality of microchannels, and the circular hole segment is used to connect the liquid inlet and outlet pipes.

[0015] Preferably, a waterproof rubber ring is provided between the heat sink liquid inlet and outlet block and the microchannel heat dissipation block, and a gasket is provided on the side wall between the rectangular hole sections of adjacent liquid inlets and liquid outlets.

[0016] Beneficial effects of the present invention: 1: By setting up the base, an installation support foundation is provided for the setting of the entire water cooling module. By setting up the parallel microchannel heat sink blocks, the gap between the two is used to provide space for the placement of the slab laser crystal, and a heat-conducting structure can be formed on both sides of the slab laser crystal, thereby improving the heat dissipation effect. At the same time, it can also provide space for the layout of the temperature monitoring unit. By setting up a shading structure, it can prevent the temperature monitoring unit from absorbing pump light and reduce the temperature measurement error. Secondly, heat dissipation is achieved by setting up a heat exchange structure in conjunction with the inlet and outlet liquid structure, thereby improving the heat dissipation capacity and effect. At the same time, the base, microchannel heat sink block, and heat sink inlet and outlet liquid block are detachably connected, which is convenient for assembly during use and for maintenance after use or in case of failure, and is convenient for disassembly and assembly.

[0017] 2. The entire water cooling module of the present invention adopts a heat dissipation method in which two microchannel heat sinks clamp the slat-shaped laser crystal. Both sides of the slat-shaped laser crystal are in contact with the microchannel heat sink, which increases the heat dissipation area and can fully dissipate the heat of the slat-shaped laser crystal. It has the characteristics of simple structure and high cooling efficiency. At the same time, the present invention has a compact structure, which can achieve full contact between the side of the slat-shaped laser crystal and the microchannel heat sink, and can achieve uniform cooling of the slat-shaped laser crystal, preventing the thermal effect caused by uneven heating from affecting the slat-shaped laser crystal.

[0018] 3. The present invention divides the structure of the heat dissipation part into a heat sink inlet and outlet block and a microchannel heat dissipation block, which are fixed in a detachable manner, which is different from the welding fixing method used for heat sinks in other conventional technologies. When the microchannel is blocked, it can be disassembled and cleaned.

[0019] 4. The present invention provides a plurality of through holes on the substrate, in which the temperature monitoring unit can be placed to measure the temperature of the slab-shaped laser crystal. In order to prevent the temperature monitoring unit from absorbing the pump light, baffles are provided before and after each temperature monitoring unit, thereby reducing the error of temperature measurement.

[0020] 5. The present invention dissipates heat from the slab-shaped laser crystal by water cooling. The exposed surface of the slab-shaped laser crystal is both the incident surface of the seed light and the amplified light in the actual optical path. By setting water inlets and liquid inlets at both ends, the heat dissipation capacity at both ends of the slab-shaped laser crystal can be increased, so that the slab-shaped laser crystal is heated evenly. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 A schematic structural diagram of a heat sink inlet and outlet liquid block from one perspective of the present invention; Figure 3 It is a structural schematic diagram of the heat sink inlet and outlet block of the present invention from another perspective; Figure 4 This is a schematic diagram of the structure of the microchannel heat sink of the present invention; Figure 5 It is a schematic diagram of the structure of the heat sink fixing plate of the present invention; Figure 6 This is a schematic diagram of the structure of the slab laser crystal of the present invention; Figure 7 A schematic diagram of the position of the slab laser crystal in the optical path diagram of the present invention; In the figure: 1: substrate, 2: microchannel heat sink, 3: slat laser crystal, 4: shading structure, 5: heat sink inlet and outlet block, 6: liquid inlet and outlet structure, 7: heat exchange structure, 11: heat sink fixing plate, 12: long waist hole, 13: through hole, 41: baffle, 71: microchannel, 72: fin, 61: liquid inlet, 62: liquid outlet, 621: rectangular hole section, 622: circular hole section, 63: waterproof rubber ring, 64: gasket. DETAILED DESCRIPTION

[0023] 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.

[0024] like Figure 1 , 2As shown, in Example 1, a microchannel water-cooling module for a four-pass slab laser amplification system includes a substrate 1, which provides an installation support foundation for the setting of the entire water-cooling module. Two microchannel heat sinks 2 are detachably arranged in parallel on the substrate 1, and the gap between the two microchannel heat sinks 2 is used to set a slab laser crystal 3. A temperature detection unit for cooperating with the slab laser crystal 3 is arranged on the substrate 1, and a shading structure 4 for cooperating with the temperature monitoring unit is arranged on the substrate 1. Through the parallel arrangement of the microchannel heat sinks, the gap between the two is used to provide space for the placement of the slab laser crystal, and a heat-conducting structure can be formed on both sides of the slab laser crystal, thereby improving the heat dissipation effect. At the same time, it can also provide space for the arrangement of the temperature monitoring unit. The shading structure can prevent the temperature monitoring unit from absorbing pump light and reduce the temperature measurement error.

[0025] In addition, the outer side of the microchannel heat sink block 2 is detachably provided with a heat sink inlet and outlet block 5, on which a liquid inlet and outlet structure 6 is provided, which is connected to a heat exchange structure 7 provided on the microchannel heat sink block 2. Heat dissipation is achieved by arranging a heat exchange structure in coordination with the liquid inlet and outlet structure, thereby improving the heat dissipation capacity and effect. In this embodiment, by detachably connecting the substrate, the microchannel heat sink block, and the heat sink inlet and outlet block, it is convenient for assembly during use and for maintenance after use or in case of failure, and is easy to disassemble and assemble. At the same time, Figure 1 , 6 As shown in , 7, the slab laser crystal 3 is a long strip structure, and the light is injected and emitted along the length direction in the optical path. The present invention can ensure the continuous stability of the heat dissipation performance in the four-pass amplification optical path, and the use effect is good. At the same time, the compact structure is also conducive to the systematization and integration of the overall structure of the laser, and can also make the side of the slab laser crystal fully contact with the microchannel heat sink, which can achieve uniform cooling of the slab laser crystal and prevent the thermal effect caused by uneven heating from affecting the slab laser crystal.

[0026] Embodiment 2, on the basis of embodiment 1, as Figure 1 , 5As shown, the base 1 includes two parallel and corresponding heat sink fixing plates 11. Among them, the two heat sink fixing plates are symmetrically arranged up and down, the thickness of the heat sink fixing plate 11 is 8mm, and a number of long waist holes 12 are opened on the heat sink fixing plate 11. The heat sink fixing plate 11 and the microchannel heat sink block 2 and / or the heat sink fixing plate 11 and the heat sink inlet and outlet block 5 are connected by bolts penetrated in the long waist holes 12. In this embodiment, the long waist holes are arranged along the width direction of the heat sink fixing plate, and four long waist holes are symmetrically arranged. Two bolts are penetrated in each long waist hole, which are respectively used to connect with the threaded holes on the top or bottom surface of the microchannel heat sink block 2 and the heat sink inlet and outlet block 5. The long waist holes are provided to facilitate fine-tuning of the position during the connection process. In addition, four connecting holes are provided on the microchannel heat sink block 2 and the heat sink inlet and outlet block 5, and the two are detachably connected by bolts provided in the connecting holes. During assembly, the microchannel heat sink block and the heat sink inlet and outlet block are first fixed together by bolts and connection holes to form a heat sink assembly, and then the slab laser crystal 3 is welded and fixed to the microchannel heat sink blocks 2 on both sides by indium welding, and finally the heat sink assembly is connected to the heat sink fixing plates 11 at the upper and lower ends by bolts. The heat sink inlet and outlet blocks and the microchannel heat sink blocks on both sides are arranged in a symmetrical structure, which can evenly conduct and dissipate heat from both sides of the slab laser crystal 3.

[0027] As a further implementation, at least one through hole 13 is provided on the heat sink fixing plate 11. In this embodiment, three through holes are provided in total, and three temperature detection units are provided in the through holes correspondingly. The temperature detection unit adopts a thermistor, which passes through the through hole and abuts against the slab laser crystal 3. The shading structure 4 includes baffles 41 fixedly provided on both sides of the through hole 13 along the length direction. In this embodiment, the baffle is 2 mm thick and 12 mm long, based on the top view of the heat sink fixing plate. The baffle 41 can be used to block the light along the length direction of the slab laser, so as to prevent the temperature detection unit from directly absorbing the pump light and causing the problem of inaccurate temperature measurement.

[0028] As a further optional implementation, an additional pair of baffles are provided outside the baffles 41 on both sides to improve the light shielding ability and the anti-interference effect.

[0029] Embodiment 3, on the basis of embodiment 2, as Figure 4As shown, the heat exchange structure 7 includes strip-shaped microchannels 71 opened in parallel on the microchannel heat sink block 2, and adjacent microchannels 71 are separated by fins 72. The microchannel 71 is opened along the length direction of the slab laser crystal 3. In this embodiment, the thickness of the two microchannel heat sink blocks 2 is 5 mm, the thickness of the heat sink inlet and outlet block is 10 mm, the microchannel heat sink block 2 and the heat sink inlet and outlet block are both rectangular structures, wherein the length of the microchannel is 64.8 mm, the width is 1 mm, the depth is 2.5 mm, the thickness of the fins between adjacent microchannels is 0.8 mm, and the number of microchannels is set to 21. The provision of multiple microchannels increases the contact area with the liquid medium flowing through, which is beneficial to heat transfer, thereby achieving efficient heat dissipation.

[0030] In addition, the liquid inlet and outlet structure 6 includes a liquid inlet 61 and a liquid outlet 62 opened on the heat sink liquid inlet and outlet block 5 along the length direction of the slab laser crystal 3. In this embodiment, the liquid inlets 61 are arranged in pairs and are respectively located on both sides of the liquid outlet 62. Specifically, each heat sink liquid inlet and outlet block is provided with two liquid inlets 61 and one liquid outlet, and the liquid inlets are respectively located on both sides of the liquid outlet. . Specifically, in this embodiment, the liquid inlets are distributed on both sides of the liquid outlet, and the slab laser crystal is cooled by water cooling. The exposed surface of the slab laser crystal is both the incident surface of the seed light and the amplified light in the actual optical path. The liquid inlets are correspondingly arranged at both ends of the slab laser crystal. With the flow of the liquid medium, the heat at both ends is taken away. Such an arrangement can effectively increase the heat dissipation capacity of the two ends of the slab crystal, so that the slab laser crystal is heated evenly.

[0031] As a further embodiment, Figure 2 , 3 As shown, the liquid inlet 61 and the liquid outlet 62 both include a connected rectangular hole segment 621 and a circular hole segment 622, the rectangular hole segment 621 is arranged on the inner side of the heat sink liquid inlet and outlet block 5, the circular hole segment 622 is arranged on the outer side of the heat sink liquid inlet and outlet block 5, the rectangular hole segment 621 is used to cooperate with a plurality of microchannels, and the circular hole segment 622 is used to connect the liquid inlet and outlet pipes. Among them, the circular hole segment is arranged to facilitate the connection, and the rectangular hole segment can be connected with a plurality of microchannels at the same time, so that the liquid medium flowing in through the circular hole segment can enter the two ends of the microchannel evenly and smoothly, and flow from the ends of the microchannel to the middle, and finally flow out through the rectangular hole segment in the middle.

[0032] In this embodiment, the inlet and outlet pipes are used to connect the pump body and the liquid storage tank, so that the pump body drives the liquid medium in the liquid storage tank to enter the microchannel through the liquid inlet and return to the liquid storage tank through the liquid outlet. In addition, as a further implementation method, the liquid storage tank is also connected to a conventional heat exchanger or air-cooled radiator, and the heat exchanger is used to dissipate heat and exchange heat for the liquid medium returning to the liquid storage tank, thereby reducing the temperature of the liquid medium.

[0033] Embodiment 4, on the basis of embodiment 3, a waterproof rubber ring 63 is provided between the heat sink inlet and outlet block 5 and the microchannel heat sink block 2, and a gasket 64 is provided on the side wall between the rectangular hole sections 621 of the adjacent liquid inlet 61 and the liquid outlet 62. In this embodiment, the waterproof rubber ring and the gasket can be made of rubber material, and the waterproof rubber ring can be used to achieve sealing to prevent water leakage. At the same time, the gasket 64 is provided to form a filling between the heat sink inlet and outlet block and the microchannel heat sink block to avoid the fluid medium between the microchannels from flowing mutually, causing the flow path to be chaotic and reducing the heat dissipation effect.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A microchannel water cooling module for a four-pass slab laser amplification system, characterized in that: The invention comprises a base body (1), two microchannel heat sinks (2) are detachably provided in parallel on the base body (1), a gap between the two microchannel heat sinks (2) is used to arrange a slab laser crystal (3), a temperature detection unit for cooperating with the slab laser crystal (3) is provided on the base body (1), and a light shielding structure (4) for cooperating with the temperature monitoring unit is provided on the base body (1); A heat sink liquid inlet and outlet block (5) is detachably provided on the outer side of the microchannel heat dissipation block (2), a liquid inlet and outlet structure (6) is provided on the heat sink liquid inlet and outlet block (5), and the liquid inlet and outlet structure (6) is connected to a heat exchange structure (7) provided on the microchannel heat dissipation block (2).

2. The microchannel water cooling module for the four-pass slab laser amplification system according to claim 1, characterized in that: The base body (1) comprises two heat sink fixing plates (11) arranged in parallel and correspondingly, the heat sink fixing plates (11) being provided with a plurality of long waist holes (12), and the heat sink fixing plates (11) and the microchannel heat sink block (2) and / or the heat sink fixing plates (11) and the heat sink liquid inlet and outlet block (5) are connected via bolts passing through the long waist holes (12).

3. The microchannel water cooling module for the four-pass slab laser amplification system according to claim 2, characterized in that: At least one penetration hole (13) is formed on the heat sink fixing plate (11), and the light shielding structure (4) comprises baffles (41) respectively fixedly arranged on both sides of the penetration hole (13) along the length direction.

4. The microchannel water cooling module for a four-pass slab laser amplification system according to any one of claims 1 to 3, characterized in that: The microchannel heat dissipation block (2) is connected to the heat sink inlet and outlet block (5) by means of bolts, and the slab laser crystal (3) is fixed to the microchannel heat dissipation block (2) by means of indium welding.

5. The microchannel water cooling module for the four-pass slab laser amplification system according to claim 4, characterized in that: The heat exchange structure (7) comprises strip-shaped microchannels (71) arranged in parallel on the microchannel heat dissipation block (2), and adjacent microchannels (71) are separated by fins (72).

6. The microchannel water cooling module for the four-pass slab laser amplification system according to claim 5, characterized in that: The microchannel (71) is opened along the length direction of the slab laser crystal (3).

7. The microchannel water cooling module for a four-pass slab laser amplification system according to any one of claims 1 to 3, 5 or 6, characterized in that: The liquid inlet and outlet structure (6) comprises a liquid inlet (61) and a liquid outlet (62) which are opened on the heat sink liquid inlet and outlet block (5) along the length direction of the slab laser crystal (3).

8. The microchannel water cooling module for the four-pass slab laser amplification system according to claim 7, characterized in that: The liquid inlets (61) are arranged in pairs and are respectively located on both sides of the liquid outlet (62).

9. The microchannel water cooling module for a four-pass slab laser amplification system according to claim 8, characterized in that: The liquid inlet (61) and the liquid outlet (62) both comprise a rectangular hole segment (621) and a circular hole segment (622) which are connected to each other; the rectangular hole segment (621) is arranged on the inner side of the heat sink liquid inlet and outlet block (5), and the circular hole segment (622) is arranged on the outer side of the heat sink liquid inlet and outlet block (5); the rectangular hole segment (621) is used to cooperate with a plurality of microchannels, and the circular hole segment (622) is used to connect the liquid inlet and outlet pipes.

10. The microchannel water cooling module for the four-pass slab laser amplification system according to claim 9, characterized in that: A waterproof rubber ring (63) is provided between the heat sink liquid inlet and outlet block (5) and the microchannel heat dissipation block (2), and a gasket (64) is provided on the side wall between the rectangular hole sections (621) of adjacent liquid inlets (61) and liquid outlets (62).

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