Overall cooling device for rodlike gain fiber

Abstract

The invention provides an overall cooling device of a rod-shaped gain optical fiber. An optical fiber laser relates to the technical field of optical fiber lasers and comprises an optical fiber placing base, an upper cover plate, an end cap cover plate and an end cap heat sink base, and the end cap cover plate and the end cap heat sink base are in one-to-one correspondence. The end cap cover plate and the end cap heat sink base are arranged at the two ends of the optical fiber placing base, the end cap heat conduction tile is wrapped between the end cap cover plate and the end cap heat sink base, the end cap heat conduction tile is used for wrapping an end cap and a welding part of the end cap, and the outer surface of the end cap heat conduction tile is in contact with the end cap cover plate and the end cap heat sink base; a refrigeration sheet is arranged at the bottom of the end cap heat sink base, the refrigeration sheet can actively refrigerate after being electrified, the refrigeration sheet is simultaneously in contact with the end cap heat sink base and the optical fiber placement base, and the optical fiber placement base, the upper cover plate, the end cap cover plate and the end cap heat sink base are all made of metal materials with high heat conductivity coefficients. The method has the effect of reducing the temperature of the end cap and the welding part.

Description

Technical Field

[0001] The invention relates to the technical field of optical fiber lasers, and in particular to an integral cooling device for a rod-shaped gain optical fiber. Background Art

[0002] In recent years, with the further development of ultrafast fiber lasers towards higher power and higher energy, the application of rod laser gain fiber has become increasingly widespread. The core diameter of this fiber (100μm) is much larger than the size of ordinary optical fiber (10μm). Due to the high doping of the fiber, the gain coefficient of the fiber is relatively high. The commonly used length is also shorter than that of ordinary optical fiber, generally in the range of 0.4 to 1.0m. At the same time, the amplification power that the fiber can support is also above 10W. The main body of the fiber is not covered with a coating layer. In order to protect the input / output end face of the fiber, large-sized end caps (6 to 8mm) need to be fused at both ends.

[0003] The rod-shaped gain fiber body needs to be heat-dissipated during operation. Since the energy at the input / output end of the fiber is too concentrated and cannot be dissipated immediately, the heat accumulation at the two ends of the fiber forms a large temperature difference, resulting in uneven heating of the fiber at the end cap. This can easily cause unpredictable thermal deformation and bending of the fiber at the end, affecting the output mode and pointing stability of the fiber.

[0004] Some use fans to dissipate heat at the end caps, but the wind will cause the suspended part of the end caps to move periodically, introducing disturbances, and the heat dissipation effect is not significant. Some also use liquid cooling, but for industrial applications, the long-term sealing effect of liquid cooling may be compromised, and leakage in the later stage will cause ablation. Summary of the invention

[0005] In order to improve the situation in which the temperature difference between the end cap and the fiber body of the existing rod-shaped laser gain fiber is too large, resulting in mode jumping and spot cracking, the present application provides an overall cooling device for the rod-shaped gain fiber.

[0006] The present application provides an overall cooling device for a rod-shaped gain optical fiber, which adopts the following technical solution:

[0007] An integral cooling device for a rod-shaped gain optical fiber, comprising:

[0008] An optical fiber placement base and an upper cover plate, wherein the upper cover plate covers the top surface of the optical fiber placement base and is used to wrap the optical fiber body therein;

[0009] One-to-one corresponding end cap cover plates and end cap heat sink bases, the corresponding end cap cover plates and end cap heat sink bases are respectively arranged at the two ends of the optical fiber placement base, the end cap cover plates correspond to the upper cover plates, the end cap heat sink base corresponds to the optical fiber placement base, an end cap thermal conductive tile is wrapped between the end cap cover plates and the end cap heat sink base, the end cap thermal conductive tile is used to wrap around the end cap and its fusion joint, and the surface of the end cap thermal conductive tile is in contact with the end cap cover plates and the end cap heat sink base;

[0010] A cooling plate is arranged at the bottom of the end cap heat sink base, and the cooling plate can actively cool after being powered on. The cooling plate is in contact with the end cap heat sink base and the optical fiber placement base at the same time. The optical fiber placement base, upper cover plate, end cap cover plate, end cap heat sink base and end cap thermal conductive tile are all made of metal materials.

[0011] Furthermore, it also includes a temperature measuring probe assembly and a temperature controller, the temperature measuring probe assembly includes a first probe, a second probe and a third probe, the first probe, the second probe and the third probe are respectively installed in the optical fiber placement base, the end cap heat sink base and the end cap cover plate, and are used to measure the internal temperature of the metal, the cooling plate and each of the temperature measuring probes are electrically connected to the temperature controller.

[0012] Furthermore, the temperature measuring probe assembly also includes a fourth probe and a fifth probe, the fourth probe is installed in the end cap cover plate, and the fifth probe is installed at the connection between the end cap heat sink base and the end cap cover plate, and the temperature measuring ends of the fourth probe and the fifth probe are close to the end cap thermal conductive tile, which are used to measure the temperature of the end cap thermal conductive tile, and the fourth probe and the fifth probe are both electrically connected to the temperature controller.

[0013] Furthermore, the temperature controller includes a temperature measuring probe group signal processing unit, a temperature feedback adjustment unit and a cooling plate driving unit, the input end of the temperature measuring probe group signal processing unit is electrically connected to the output end of each temperature measuring probe, the output end of the temperature measuring probe group signal processing unit is electrically connected to the input end of the temperature feedback adjustment unit, the output end of the temperature feedback adjustment unit is electrically connected to the input end of the cooling plate driving unit, and the output end of the cooling plate driving unit is electrically connected to the input end of the cooling plate.

[0014] Furthermore, the distance between the temperature measuring end of the fourth probe and the fifth probe and the end cap thermal conductive tile is 0.4-0.5 mm.

[0015] Furthermore, the optical fiber placement base, upper cover plate, end cap cover plate and end cap heat sink base are all made of aluminum alloy, copper alloy or stainless steel.

[0016] Furthermore, it also includes an end cap thermally conductive film, which is used to cover the outside of the end cap, and the end cap thermally conductive film is tightly fitted to the inner wall of the end cap thermally conductive tile.

[0017] Furthermore, a first thermal insulation block is arranged between the end cap cover plate and the upper cover plate, which is used to separate the end cap cover plate from the upper cover plate; a second thermal insulation block is arranged between the end cap heat sink base and the optical fiber placement base, which is used to separate the end cap heat sink base from the optical fiber placement base; the first thermal insulation block and the second thermal insulation block are both made of hard materials with low thermal conductivity.

[0018] Furthermore, the optical fiber placement base, the end cap heat sink base, and the second thermal insulation block are each provided with a placement groove for placing the optical fiber body, and the placement groove is filled with thermal conductive silicone, and the thermal conductive silicone is used to fill the gap between the optical fiber body and the placement groove.

[0019] In summary, this application has the following beneficial effects:

[0020] 1. An end cap cover plate and an end cap heat sink base are arranged outside the end cap, and the end cap cover plate and the end cap heat sink base wrap the end cap together, and the end cap cover plate and the end cap heat sink base are both made of a metal material with a high thermal conductivity, so that the end cap cover plate and the end cap heat sink base can perform independent heat dissipation on the end cap; a cooling plate is arranged at the bottom of the end cap heat sink base, and the cooling plate can actively cool. When the end cap is working, the heat is transferred to the cooling plate through the end cap heat sink base, and the cooling plate effectively absorbs the heat generated by the end cap, thereby performing targeted heat dissipation on the end cap, ensuring that when the optical fiber is working, the end cap and the optical fiber will not be affected by a large temperature difference, which is beneficial to the output stability of the optical fiber under heating, and reduces the disturbance introduced by the heating of the output part of the optical fiber end cap;

[0021] 2. By using a temperature controller and a temperature probe assembly, the first probe, the second probe, and the third probe measure the temperature of the optical fiber placement base, the end cap heat sink base, and the end cap cover respectively, and the fourth probe and the fifth probe monitor the temperature of the end cap thermal conductive tile from different positions. Each temperature probe feeds back the monitoring data to the temperature controller in real time. The temperature controller automatically adjusts the temperature at the end cap in real time by controlling the cooling capacity of the refrigeration plate, thereby ensuring the long-term temperature stability at the optical fiber end cap, and further ensuring the stability of the light spot pattern when the rod-shaped optical fiber works for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram showing the overall structure of the cooling device in the embodiment of the present application;

[0023] Figure 2 It is a structural schematic diagram showing the end cap fixing and heat dissipation method of the embodiment of the present application;

[0024] Figure 3 is a partial cross-sectional view showing a method for fixing an optical fiber body according to an embodiment of the present application;

[0025] Figure 4is a schematic structural diagram showing the end face of a cooling device according to an embodiment of the present application;

[0026] Figure 5 It is a partial cross-sectional view showing the installation position of the temperature measuring probe in the embodiment of the present application;

[0027] Figure 6 This is a comparison diagram of the optical fiber output modes before and after the cooling device is used in the embodiment of the present application.

[0028] Explanation of the reference numerals: 1. optical fiber placement base; 11. placement groove; 12. thermal conductive silicone; 13. second thermal insulation block; 14. first probe; 2. upper cover plate; 21. first thermal insulation block; 3. optical fiber body; 31. end cap; 32. end cap thermal conductive film; 4. end cap cover plate; 41. third probe; 42. fourth probe; 5. end cap heat sink base; 51. second probe; 6. end cap thermal conductive tile; 7. cooling plate; 8. temperature controller; 9. fifth probe. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present application clearer, the following will further describe the implementation mode of the present application in conjunction with the accompanying drawings. The following is a preferred embodiment of the present application among multiple possible embodiments, which is intended to provide a basic understanding of the present application, but is not intended to confirm the key or decisive elements of the present application or to limit the scope of protection.

[0030] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0031] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0032] In the description of this application, it should be noted that the circuits, electronic components and modules involved in this application are all prior art and can be fully implemented by those skilled in the art without further elaboration. The content protected by this application does not involve improvements to the internal structure and methods.

[0033] It should be further explained that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it 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 an indirect connection 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 this application can be understood according to specific circumstances.

[0034] The embodiment of the present application provides an overall cooling device for a rod-shaped gain optical fiber, referring to Figure 1 and Figure 2 The overall cooling device of the rod-shaped gain optical fiber includes an upper and lower corresponding optical fiber placement base 1 and an upper cover plate 2. The width of the optical fiber placement base 1 and the upper cover plate 2 are corresponding, and both are rectangular in shape. The upper cover plate 2 is correspondingly covered on the top surface of the optical fiber placement base 1, and the optical fiber body 3 is located between the optical fiber placement base 1 and the upper cover plate 2. The optical fiber body 3 is a rod-shaped gain optical fiber, which is used to amplify the gain of the laser. Both ends of the optical fiber body 3 are fixed with end caps 31 by fusion, and the outer diameter of the end cap 31 is larger than the outer diameter of the optical fiber body 3. Specifically, the optical fiber mode field diameter is 85μm, and the optical fiber amplification output power is greater than 10W.

[0035] Reference Figure 2 and Figure 3 The top surface of the optical fiber placement base 1 is provided with a placement groove 11 along its length direction, and the bottom surface of the upper cover plate 2 is provided with a matching groove at a position corresponding to the placement groove 11, and the optical fiber body 3 is placed in the placement groove 11. In the embodiment of the present application, the placement groove 11 can be a U-shaped groove with an opening facing upward, and the width of the U-shaped groove is 10 to 50 μm larger than the maximum diameter of the optical fiber body 3, so that the optical fiber body 3 does not contact the inner wall surface of the placement groove 11.

[0036] The gap between the optical fiber body 3 and the placement groove 11 is filled with transparent thermal conductive silicone 12. The thermal conductive silicone 12 has good thermal conductivity and can transfer the heat generated by the optical fiber body 3 during operation to the optical fiber placement base 1 in time. While firmly fixing the optical fiber body 3 in the placement groove 11, it is also convenient to dissipate heat for the optical fiber body 3, which is more conducive to the amplification and stability of the optical fiber body 3.

[0037] Reference Figures 1 to 4 , the two ends of the optical fiber placement base 1 are provided with corresponding end cap cover plates 4 and end cap heat sink bases 5, wherein the end cap cover plates 4 correspond to the upper cover plate 2, and the end cap heat sink base 5 corresponds to the optical fiber placement base 1. The optical fiber placement base 1, the upper cover plate 2, the end cap cover plates 4 and the end cap heat sink base 5 are all made of metal materials with high thermal conductivity. In the embodiment of the present application, these metal materials with high thermal conductivity can be metal alloy materials of aluminum alloy, copper alloy or stainless steel, and can also be other metals or metal alloys with high thermal conductivity, as long as they have good thermal conductivity.

[0038] The end cap cover plate 4 and the end cap heat sink base 5 are respectively located on the upper and lower sides of the end cap 31, and are used to fix the position of the end cap 31. The end cap heat conductive tile 6 is wrapped between the end cap cover plate 4 and the end cap heat sink base 5. Specifically, the end cap heat conductive tile 6 is two with the same appearance, and is respectively wrapped on the upper and lower sides of the end cap 31, so that the two end cap heat conductive tiles 6 are assembled into a complete cylinder. The end cap heat conductive tile 6 is wrapped around the outside of the end cap 31 and its welding part, and is in contact with the end cap cover plate 4 and the end cap heat sink base 5 at the same time. The end cap heat conductive tile 6 is also made of metal materials with high thermal conductivity such as aluminum alloy, copper alloy or stainless steel, which can accelerate the transfer of heat generated by the end cap 31.

[0039] Furthermore, in order to further improve the heat transfer efficiency, the outer surface of the end cap 31 is also coated with an end cap thermal conductive film 32, and the end cap thermal conductive film 32 is tightly attached to the inner wall of the end cap thermal conductive tile 6. The end cap thermal conductive film 32 can be a high thermal conductive film formed by evaporating a lightweight high thermal conductive material onto the outer wall of the end cap 31 using magnetron sputtering coating technology, and the lightweight thermal conductive material can be silicon carbide, boron nitride or aluminum oxide. The end cap thermal conductive film 32 can further accelerate the heat conduction of the surface heat of the end cap 31, effectively improving the heat transfer efficiency.

[0040] Furthermore, a first thermal insulation block 21 is provided between the end cap cover plate 4 and the upper cover plate 2, and the first thermal insulation block 21 separates the end cap cover plate 4 from the upper cover plate 2. Meanwhile, a second thermal insulation block 13 is provided between the end cap heat sink base 5 and the optical fiber placement base 1, and the second thermal insulation block 13 separates the end cap heat sink base 5 from the optical fiber placement base 1. Both the first thermal insulation block 21 and the second thermal insulation block 13 are made of hard materials with low thermal conductivity. Specifically, these hard materials with low thermal conductivity can be materials such as polyethylene or polymethyl methacrylate, so that the first thermal insulation block 21 and the second thermal insulation block 13 can effectively block the transfer of heat.

[0041] Specifically, the first thermal insulation block 21 is separated from the side of the end cap cover plate 4, and separates the end cap heat conductive tile 6 from the upper cover plate 2. The second thermal insulation block 13 is covered on the side and bottom of the end cap heat sink base 5, so that the first thermal insulation block 21 and the second thermal insulation block 13 completely separate the end cap 31 from the optical fiber body 3, reducing the heat transfer between the end cap 31 and the optical fiber body 3. The end cap heat sink base 5 is installed on the second thermal insulation block 13, and the end cap heat sink base 5 and the second thermal insulation block 13 are integrally embedded in the end of the optical fiber placement base 1. The placement groove 11 runs through the first thermal insulation block 21 and the second thermal insulation block 13 at the same time. The above-mentioned components are all fixed together by bolt connection, for example, the optical fiber placement base 1 and the upper cover plate 2, the end cap cover plate 4 and the end cap heat sink base 5, etc. are all fixedly connected by tightening bolts, so that the connection between the components is stable, thereby ensuring the overall stability and reliability of the device, thereby ensuring the output stability of the gain optical fiber.

[0042] Reference Figure 1 and Figure 2 In order to further improve the heat dissipation efficiency of the end cap 31, a cooling plate 7 is arranged at the bottom of the end cap heat sink base 5. The cooling plate 7 can actively cool the body after power is turned on. The top surface of the cooling plate 7 is in contact with the bottom surface of the end cap heat sink base 5, and the bottom surface of the cooling plate 7 is in contact with the optical fiber placement base 1. The cooling plate 7 is embedded and fixed inside the second insulation block 13, thereby fixing the position of the cooling plate 7.

[0043] Since the optical fiber generates heat when working, the generated heat is transferred outward through the end cap heat sink base 5 and the optical fiber placement base 1. The cooling plate 7 is in contact with the end cap heat sink base 5 and the optical fiber placement base 1 at the same time, so that the cooling plate 7 can actively absorb the heat transferred from the end cap heat sink base 5 and the optical fiber placement base 1 after active cooling, and conduct the generated heat through the optical fiber placement base 1, thereby realizing separate heat dissipation at the fusion joint of the end cap 31, realizing active cooling of the end cap 31 position, further reducing the temperature of the end cap 31 position, and reducing the temperature difference between the end cap 31 position and the optical fiber body 3.

[0044] In order to facilitate the adjustment of the temperature of the cooling plate 7, a temperature controller 8 is also provided on the outside. The temperature controller 8 includes a temperature probe group signal processing unit, a temperature feedback adjustment unit and a cooling plate 7 driving unit, wherein the output end of the cooling plate 7 driving unit is electrically connected to the input end of the cooling plate 7, so that the cooling power of the cooling plate 7 can be automatically controlled by the temperature controller 8.

[0045] Reference Figure 1 and Figure 5 In order to monitor the temperature inside the device in real time, the cooling device also includes a temperature measuring probe assembly, which includes a first probe 14, a second probe 51 and a third probe 41, wherein the first probe 14, the second probe 51 and the third probe 41 are respectively installed in the optical fiber placement base 1, the end cap heat sink base 5 and the end cap cover plate 4, and each temperature measuring probe is a common temperature sensor in the art, which can measure the internal temperature of the metal in real time. The first probe 14, the second probe 51 and the third probe 41 are all distributed around the position of the end cap 31, mainly monitoring the real-time temperature near the end cap 31, and the three probes are distributed in different components, which can monitor the optical fiber placement base 1, the end cap heat sink base 5 and the end cap cover plate 4 respectively.

[0046] The temperature measuring probe assembly also includes a fourth probe 42 and a fifth probe 9, wherein the fourth probe 42 is installed in the end cap cover plate 4, and the fifth probe 9 is installed at the connection between the end cap heat sink base 5 and the end cap cover plate 4. The fourth probe 42 and the fifth probe 9 have the same function as the above-mentioned probes, and both monitor the temperature in real time. The difference is that the actual temperature measuring ends of the fourth probe 42 and the fifth probe 9 are close to the end cap thermal conductive tile 6. In the embodiment of the present application, the distance between the temperature measuring ends of the fourth probe 42 and the fifth probe 9 and the end cap thermal conductive tile 6 is 0.4 to 0.5 mm, and any distance can be taken, that is, the temperature measuring ends of the fourth probe 42 and the fifth probe 9 are closely close to the end cap thermal conductive tile 6 from different directions, so as to measure the temperature of the end cap thermal conductive tile 6. The closer the temperature measuring ends of the fourth probe 42 and the fifth probe 9 are to the end cap 31 insulation tile, the more accurate the actual detected temperature is, and the better the temperature control effect is. In the embodiment of the present application, all of the above-mentioned temperature measuring probes are packaged by thermal conductive adhesive, which can fix the position of each probe and improve the temperature measurement sensitivity of each probe.

[0047] In the temperature controller 8, the input end of the temperature probe group signal processing unit is electrically connected to the output end of each temperature probe, the output end of the temperature probe group signal processing unit is electrically connected to the input end of the temperature feedback adjustment unit, and the output end of the temperature feedback adjustment unit is electrically connected to the input end of the refrigeration plate 7 driving unit.

[0048] Specifically, the temperature controller 8 can write the temperature control program in the temperature feedback adjustment unit, and set the corresponding refrigeration temperature difference threshold, adjust the temperature output on the refrigeration plate 7 in real time through the temperature feedback of each probe, and continuously control the temperature change at the fusion joint of the gain fiber end cap 31. The end cap 31 and the rod-shaped optical fiber body 3 are cooled in sections. For example, the temperature is set to 20°C, and the temperature near the end cap 31 is detected to drive the refrigeration plate 7 to output refrigeration, which is transmitted to the end cap heat sink base 5, thereby reducing the temperature around the end cap thermal conductive tile 6, and then reducing the temperature of the end cap thermal conductive film 32, thereby reducing the temperature of the end cap 31 and the fusion joint, so as to achieve uniform heating of the entire rod-shaped gain fiber and control the temperature difference as small as possible.

[0049] Reference Figure 6 , Figure 6 The figure shows the comparison of the optical fiber output modes in the experiment of the present invention. A rod-shaped gain optical fiber with a core diameter of 85 μm is used, a 10W signal with a wavelength of 1030 nm is input, and a 976 nm pump is used. Figure 6 The left figure in the figure is the near-field spot mode when the gain optical fiber outputs 200W power using the cooling of the present invention, and the right figure is the near-field spot mode when the optical fiber outputs 200W power without turning on the cooling device. By comparison, it can be seen that the spots are significantly different. The spot on the right is an irregular circular shape, and the mode begins to crack, indicating that the device of the present invention has a good effect on maintaining the high-power mode of the optical fiber.

[0050] The implementation principle of the overall cooling device of a rod-shaped gain optical fiber in the embodiment of the present application is as follows: the end cap cover plate 4 and the end cap heat sink base 5 made of a metal material with a high thermal conductivity coefficient jointly wrap the end cap 31, and the end cap 31 can be independently cooled; the end cap 31 generates heat during operation, and the heat is transferred to the cooling plate 7 through the end cap heat sink base 5. The cooling plate 7 effectively absorbs the heat generated by the end cap 31, thereby performing targeted heat dissipation at the end cap 31, ensuring that the end cap 31 and the optical fiber are not affected by a large temperature difference when the optical fiber is working, which is beneficial to the output stability of the optical fiber under heating and reduces the disturbance introduced by the heating of the output part of the optical fiber end cap 31; each temperature measuring probe monitors the temperature around the end cap 31 from different positions, and after feeding back the monitoring data to the temperature controller 8 in real time, the temperature controller 8 automatically adjusts the temperature at the end cap 31 in real time by controlling the cooling capacity of the cooling plate 7, thereby ensuring the long-term stability of the temperature at the optical fiber end cap 31, and further ensuring the stability of the light spot pattern when the rod-shaped optical fiber works for a long time.

[0051] In this article, the directional words such as front, back, top, and bottom involved are defined by the positions of the parts in the drawings and the positions of the parts relative to each other, just for the sake of clarity and convenience in expressing the technical solution. It should be understood that they are relative concepts and can change accordingly according to different ways of use and placement, and the use of the directional words should not limit the scope of protection claimed in this application.

[0052] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other.

[0053] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An integral cooling device for a rod-shaped gain optical fiber, characterized in that: include An optical fiber placement base and an upper cover plate, wherein the upper cover plate covers the top surface of the optical fiber placement base and is used to wrap the optical fiber body therein; One-to-one corresponding end cap cover plates and end cap heat sink bases, the corresponding end cap cover plates and end cap heat sink bases are respectively arranged at the two ends of the optical fiber placement base, the end cap cover plates correspond to the upper cover plates, the end cap heat sink base corresponds to the optical fiber placement base, an end cap thermal conductive tile is wrapped between the end cap cover plates and the end cap heat sink base, the end cap thermal conductive tile is used to wrap around the end cap and its fusion joint, and the surface of the end cap thermal conductive tile is in contact with the end cap cover plates and the end cap heat sink base; A cooling plate is arranged at the bottom of the end cap heat sink base, and the cooling plate can actively cool after being powered on. The cooling plate is in contact with the end cap heat sink base and the optical fiber placement base at the same time. The optical fiber placement base, upper cover plate, end cap cover plate, end cap heat sink base and end cap thermal conductive tile are all made of metal materials.

2. The overall cooling device for rod-shaped gain optical fiber according to claim 1, characterized in that: It also includes a temperature measuring probe assembly and a temperature controller. The temperature measuring probe assembly includes a first probe, a second probe and a third probe. The first probe, the second probe and the third probe are respectively installed in the optical fiber placement base, the end cap heat sink base and the end cap cover plate, and are used to measure the internal temperature of the metal. The cooling plate and each of the temperature measuring probes are electrically connected to the temperature controller.

3. The overall cooling device for rod-shaped gain optical fiber according to claim 2, characterized in that: The temperature measuring probe assembly also includes a fourth probe and a fifth probe. The fourth probe is installed in the end cap cover plate, and the fifth probe is installed at the connection between the end cap heat sink base and the end cap cover plate. The temperature measuring ends of the fourth probe and the fifth probe are close to the end cap thermal conductive tile, which are used to measure the temperature of the end cap thermal conductive tile. The fourth probe and the fifth probe are both electrically connected to the temperature controller.

4. The overall cooling device for rod-shaped gain optical fiber according to claim 3, characterized in that: The temperature controller includes a temperature measuring probe group signal processing unit, a temperature feedback adjustment unit and a refrigeration plate driving unit. The input end of the temperature measuring probe group signal processing unit is electrically connected to the output end of each temperature measuring probe, the output end of the temperature measuring probe group signal processing unit is electrically connected to the input end of the temperature feedback adjustment unit, the output end of the temperature feedback adjustment unit is electrically connected to the input end of the refrigeration plate driving unit, and the output end of the refrigeration plate driving unit is electrically connected to the input end of the refrigeration plate.

5. The overall cooling device for rod-shaped gain optical fiber according to claim 3, characterized in that: The distance between the temperature measuring end of the fourth probe and the fifth probe and the end cap thermal conductive tile is 0.4-0.5 mm.

6. The overall cooling device for rod-shaped gain optical fiber according to claim 1, characterized in that: The optical fiber placement base, upper cover plate, end cap cover plate and end cap heat sink base are all made of aluminum alloy, copper alloy or stainless steel.

7. The overall cooling device for rod-shaped gain optical fiber according to claim 1, characterized in that: It also includes an end cap heat-conducting film, which is used to cover the end cap, and the end cap heat-conducting film is tightly fitted to the inner wall of the end cap heat-conducting tile.

8. The overall cooling device for rod-shaped gain optical fiber according to claim 1, characterized in that: A first thermal insulation block is arranged between the end cap cover plate and the upper cover plate, which is used to separate the end cap cover plate from the upper cover plate. A second thermal insulation block is arranged between the end cap heat sink base and the optical fiber placement base, which is used to separate the end cap heat sink base from the optical fiber placement base. The first thermal insulation block and the second thermal insulation block are both made of hard materials with low thermal conductivity.

9. The overall cooling device for rod-shaped gain optical fiber according to claim 8, characterized in that: The optical fiber placement base, the end cap heat sink base, and the second thermal insulation block are each provided with a placement groove for placing the optical fiber body. The placement groove is filled with thermal conductive silicone, and the thermal conductive silicone is used to fill the gap between the optical fiber body and the placement groove.

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