Fiber laser tube shell

Abstract

The utility model discloses an optical fiber laser tube shell, which is used for packaging an optical fiber laser or other laser generating components, and heat dissipation fins for air cooling are integrally formed on the lower surface of a bottom plate of the laser tube shell, so that the heat resistance can be effectively reduced, and efficient heat dissipation can be realized. A refrigerant pipeline can also be embedded in the bottom plate of the laser tube shell, and the refrigerant pipeline can be used for circulating refrigerants such as phase change refrigerants or water; a side plate of an ordinary laser tube shell is omitted, materials are saved, the device is thinned, meanwhile, the packaging mode and process are simpler, in addition, due to the multi-area independent packaging mode, part of parts can be replaced without opening the whole package when the parts are damaged, and the cost is reduced. And the influence on the stability of the whole device when part of devices are damaged is reduced to the maximum extent.

Description

Technical Field

[0001] The utility model relates to a fiber laser tube shell, in particular to a packaging tube shell of a high-power fiber laser. Background Art

[0002] With the development of lasers, the power of existing lasers is getting higher and higher. Therefore, the heat dissipation requirements of lasers are getting higher and higher. In the past, lasers were mostly packaged / sealed using tube shells, and multiple semiconductor laser chips were installed on the base of the tube shell to form a single pump module. The heat generated by the semiconductor laser chip was transferred to the base of the tube shell. The base of the existing tube shell is installed on a cold plate through thermal grease, etc. The base of the tube shell transfers the heat to the cold plate, and then conducts heat and dissipates heat through the cold plate. We realized that this type of heat dissipation will form heat accumulation at the contact position of the tube shell and the cold plate due to the effect of the tube shell, that is, due to the thermal conductivity gradient of heat conduction, resulting in a high temperature of the semiconductor laser chip, and excessive temperature can easily damage the semiconductor laser chip. In order to solve this problem, we decided to adopt a new packaging method, abandoning the original technical solution of using an ordinary tube shell and installing the laser tube shell on a cold plate, and instead designing a new tube shell. Utility Model Content

[0003] The utility model aims to provide a fiber laser tube shell, which can have a better heat dissipation capability while having a good sealing package.

[0004] In order to solve the above problems, the utility model provides a fiber laser tube shell, including a bottom plate of the laser tube shell, the bottom plate supports a laser generating component; the laser generating component includes a plurality of semiconductor laser chips and an optical gain cavity part; the bottom plate of the laser tube shell includes a semiconductor laser chip placement area and an optical gain cavity placement area, and the optical gain cavity part and the semiconductor laser chip are packaged on the bottom plate of the laser tube shell; at least one semiconductor chip packaging top plate is arranged on the semiconductor chip placement area; at least one semiconductor chip packaging top plate and the bottom plate cooperate to form a package for a plurality of semiconductor laser chips; the utility model is characterized in that: the bottom plate of the laser tube shell includes a plate-shaped body, the first surface of the body is used to receive the heat generated by the heat source and conduct it downward, the second surface of the body is formed with heat dissipation fins, and the heat on the heat dissipation fins on the lower surface of the body can be taken away by air cooling, the body and the heat dissipation fins are integrally formed, and the body and the heat dissipation fins are both made of heat conductive material.

[0005] Preferably, a pipeline is buried in the bottom plate of the laser tube shell, and a refrigerant flows in the pipeline.

[0006] Preferably, the pipeline is located in the body, and water refrigerant or phase change refrigerant flows through the pipeline in the body; the body and the heat dissipation fins are both made of aluminum or graphene.

[0007] Preferably, a plurality of semiconductor laser chips are divided into N semiconductor laser chip groups, each semiconductor laser chip group jointly outputs a pump laser, and multiple pump laser beams enter the gain cavity fiber after being combined through spatial photosynthesis or a beam combiner. There are N semiconductor chip packaging top plates, and each semiconductor chip packaging top plate is used to cover a corresponding semiconductor laser chip group, that is, N semiconductor chip packaging top plates and laser tube shell bottom plates cooperate to package N semiconductor laser chip groups, and N is an integer greater than 1.

[0008] Preferably, at least one semiconductor laser chip is mounted on the surface of the semiconductor laser chip placement area and is in thermal contact with the semiconductor laser chip, an active optical fiber is mounted on the surface of the gain cavity placement area and is in thermal contact with the active optical fiber, at least one semiconductor laser chip outputs pump light through an output pigtail, the pump light is coupled into the active optical fiber through a coupler, and fiber laser is generated and output through the active optical fiber.

[0009] Preferably, the gain cavity fiber placement area has a second fin area at the lower side, the semiconductor laser chip placement area has a first fin area at the lower side, and the length of the fins of the first fin area extending downward is twice or more than the length of the fins of the second fin area extending downward.

[0010] Preferably, an optical gain cavity packaging top plate is arranged on the gain cavity fiber placement area; the optical gain cavity packaging top plate and the laser tube shell bottom plate cooperate to form packaging for the gain cavity fiber.

[0011] Preferably, the bottom plate of the tube shell adopts a solid structure.

[0012] Preferably, a pipeline is buried in the bottom plate of the laser tube shell, and a refrigerant flows in the pipeline. The pipeline density in the semiconductor laser chip placement area is P1, and the pipeline density in the gain cavity fiber placement area is P2, and P1>P2.

[0013] Preferably, when phase change refrigerant flows in the pipeline, the pipeline in the bottom plate of the laser tube shell is connected to the refrigerant pipeline of the external compression refrigeration device; when water refrigerant flows in the pipeline, the pipeline in the bottom plate of the laser tube shell is connected to the external water supply pipe and drainage pipe.

[0014] The beneficial effect of the utility model is that a new type of fiber laser tube shell abandons the existing technical solution of setting a cold plate on the lower side of the tube shell bottom plate, and can have a good packaging effect while having a better heat dissipation effect. The bottom plate of the laser tube shell includes a plate-shaped body, the first surface of the body is used to receive the heat generated by the heat source and conduct it downward, and the second surface of the body forms a heat dissipation fin, which can take away the heat on the heat dissipation fin on the lower surface of the body by air cooling. The body and the heat dissipation fin are integrally formed.

[0015] A refrigerant pipe is set in the bottom plate of the tube shell, and a heat sink is formed on the lower side of the bottom plate, which can effectively utilize the heat conductivity of the non-pipeline area in the bottom plate of the tube shell and realize double heat dissipation to improve the heat dissipation efficiency. It can have the effects of phase change cooling and direct air cooling at the same time, or the effects of water cooling and direct air cooling. In order to reduce the thermal resistance of air cooling and improve the heat dissipation capacity of air cooling.

[0016] The bottom plate of the laser tube shell includes a semiconductor laser chip placement area and a gain cavity fiber placement area, which can effectively realize the packaging and effective heat dissipation of the current fiber laser, eliminating the usual side plate of the laser tube shell, not only saving materials to make the device thinner, but also making the packaging method and process simpler. In addition, due to the multi-zone independent packaging method, it is convenient to replace some parts without opening the overall package when they are damaged, thereby minimizing the impact on the stability of the overall device when some components are damaged; at the same time, in order to achieve more effective and more balanced heat dissipation, the fins on the lower side of the gain cavity fiber placement area are longer than the fins on the lower side of the semiconductor laser chip placement area. A pipeline is buried in the bottom plate of the laser tube shell, and a refrigerant circulates in the pipeline. The pipeline density in the semiconductor laser chip placement area is P1, and the pipeline density in the gain cavity fiber placement area is P2, and P1>P2. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the utility model.

[0018] Figure 2 It is an explosion schematic diagram of the utility model.

[0019] Figure 3 It is a front schematic diagram of the utility model.

[0020] Figure 4 It is a schematic diagram of the back side of the utility model.

[0021] Figure 5 It is a longitudinal side schematic diagram of the utility model.

[0022] Figure 6 It is a pipeline schematic diagram of the utility model.

[0023] Figure 7 It is a horizontal side schematic diagram of the utility model. DETAILED DESCRIPTION

[0024] The technical solution of the utility model is further explained below with reference to the accompanying drawings and through specific implementation methods.

[0025] Existing lasers usually use semiconductor lasers as pump sources or part of the light source, and the heat generated by semiconductor laser chips is extremely large. Therefore, in lasers, it is most important to dissipate heat for semiconductor chips. In the usual technical solution, multiple semiconductor laser chips are used in the pump source or light source as a group of semiconductor laser chip modules, and multiple semiconductor laser chips have a common tube shell for packaging / sealing. The tube shell can be called a laser tube shell. Multiple semiconductor laser chips are installed on the base of the tube shell. The heat generated by the semiconductor laser chips is conducted to the base of the tube shell. The base of the existing tube shell is installed on a cold plate. The base of the tube shell transfers the heat to the cold plate, and then conducts heat and dissipates heat through the cold plate. We realize that although this method is convenient for sealing, its heat dissipation is due to the effect of the tube shell. Due to the thermal conductivity gradient of heat conduction, heat accumulation will be formed at the contact position of the tube shell and the cold plate, resulting in increased difficulty in heat dissipation of the semiconductor laser chip and low heat dissipation efficiency, and excessively high temperature will easily damage the semiconductor laser chip. In order to solve this problem, we decided to adopt a new packaging method, abandoning the original technical solution of using an ordinary tube shell and installing the laser tube shell on a cold plate. Instead, we designed a water-cooled / phase-change cooling tube shell and a direct air-cooled tube shell, and directly installed multiple semiconductor chips on the water-cooled / phase-change cooling tube shell and the direct air-cooled tube shell.

[0026] The specific scheme is as follows: a new type of fiber laser tube shell, including a bottom plate on the lower side and multiple packaging top plates on the upper side, a laser generating component is fixedly installed on the bottom plate of the laser tube shell; the laser generating component includes a plurality of semiconductor laser chips, a gain cavity fiber part and other related components, the bottom plate on the lower side is divided into a semiconductor laser chip placement area and an optical gain cavity placement area, a plurality of semiconductor laser chips are supported on the semiconductor chip placement area, and active optical fibers and devices are supported and arranged on the gain cavity fiber placement area; at least one semiconductor chip packaging top plate is arranged on the semiconductor chip placement area, and an optical gain cavity packaging top plate is preferably arranged on the gain cavity fiber placement area; at least one semiconductor chip packaging top plate and the bottom plate cooperate to form a package / seal for a plurality of semiconductor laser chips; preferably, when the plurality of semiconductor laser chips can be divided into N semiconductor laser chip groups, each semiconductor laser chip group jointly outputs a beam of pump laser, and multiple beams of pump laser are combined through spatial photosynthesis or entering a beam combiner and then entering the gain cavity light beam. The optical fiber preferably has N semiconductor chip packaging top plates, each of which is used to cover a corresponding semiconductor laser chip group, that is, a semiconductor chip group is packaged between the bottom plate of the laser tube shell and a corresponding semiconductor chip top plate, that is, N semiconductor chip packaging top plates and the bottom plate of the laser tube shell cooperate to package N semiconductor laser chip groups; preferably, the optical gain cavity packaging top plate and the bottom plate of the laser tube shell cooperate to form a package / seal for the active optical fiber, and the optical gain cavity packaging top plate covers the gain cavity fiber part, that is, the gain cavity fiber part is packaged between the bottom plate of the laser tube shell and the optical gain cavity packaging top plate; such a configuration can save the usual side plate of the laser tube shell, not only saving materials to make the device thinner, but also making the packaging method and process simpler. In addition, due to the multi-zone independent packaging method, it is convenient to replace some parts without opening the overall packaging when they are damaged, and the influence on the stability of the overall device when some devices are damaged is minimized. N is an integer greater than 1. Preferably, the semiconductor chip packaging top plate can be a cover plate with a groove or a flat cover plate.

[0027] The laser generating component is an optical component that can generate the final output laser or the intermediate process laser. The laser generating component may include a semiconductor laser chip, a collimating / coupling component, a gain cavity fiber part, etc., and in some embodiments, a passive fiber is also included. Preferably, the bottom plate of the laser tube shell includes a plate-shaped body, the body is made of a heat-conducting material, and the first surface (upper surface) of the body is used to receive the heat generated by the heat source and conduct it downward. In order to improve the heat dissipation efficiency, a pipeline is buried in the bottom plate of the tube shell, and a pipeline is arranged in the body. A refrigerant can flow in the pipeline. Specifically, when water cooling is adopted, water refrigerant flows in the pipeline in the body, and when a compression cooling scheme is adopted, a phase change refrigerant flows in the pipeline in the body. Preferably, a heat dissipation fin is formed on the second surface (lower surface) of the body, and the heat on the heat dissipation fin on the lower surface of the body can be continuously taken away by air cooling (a device for accelerating the air flow, such as a fan, can be provided in conjunction). Thus, the heat conduction capacity of the non-pipeline area in the bottom plate of the tube shell can be effectively utilized and double heat dissipation can be achieved to improve the heat dissipation efficiency, and the effects of phase change cooling and direct air cooling can be achieved at the same time, or the effects of water cooling and direct air cooling can be achieved. In order to reduce the thermal resistance of air cooling and improve the heat dissipation capacity of air cooling, preferably, the body and the heat dissipation fins are integrally formed, and the body and the heat dissipation fins are made of thermally conductive materials, especially the body and the heat dissipation fins are made of highly thermally conductive materials, such as highly thermally conductive aluminum and graphene materials. Of course, in a non-preferred embodiment, a purely air-cooled laser tube shell bottom plate can also be used, that is, the body of the bottom plate of the laser tube shell is made of thermally conductive materials, and the bottom plate of the tube shell adopts a solid structure, but heat dissipation fins are formed on the second surface (lower surface) of the body, and the heat on the heat dissipation fins on the lower surface of the body can still be continuously taken away by air cooling.

[0028] refer to Figure 3 , 4, so that the gain cavity fiber and the semiconductor laser chip are simultaneously packaged on the bottom plate of the laser tube shell, that is, the bottom plate of the laser tube shell includes a semiconductor laser chip placement area and an optical gain cavity placement area, at least one semiconductor laser chip is installed on the surface of the semiconductor laser chip placement area and is in thermal contact with the semiconductor laser chip, and an active optical fiber and a device are installed on the surface of the optical gain cavity placement area and are in thermal contact with it, at least one semiconductor laser chip outputs pump light through an output pigtail, and the pump light couples the pump light of the output pigtail into the gain cavity fiber through a fiber combiner or other coupler, and generates and outputs fiber laser through the active fiber (that is, the semiconductor laser chip, the active optical fiber and other related optical components together constitute the laser generation component of the fiber laser); preferably, the gain cavity fiber is a closed-loop winding structure in which multiple arc segments are sequentially connected to form an 8-shaped structure to increase the gain efficiency and reduce the excitation of high-order modes. That is, a fiber laser is arranged on the bottom plate of the laser tube shell, and the fiber laser is packaged by the laser tube shell, that is, the semiconductor laser chip is packaged between the bottom plate of the laser tube shell and the top plate of the semiconductor chip package; the gain cavity fiber part is packaged between the bottom plate of the laser tube shell and the top plate of the optical gain cavity package. Since the heat generated by the semiconductor laser chip is more than the gain cavity fiber, in order to dissipate heat more effectively and more evenly, preferably, the fins on the lower side of the semiconductor laser chip placement area are longer than the fins on the lower side of the optical gain cavity placement area, that is, the lower side of the optical gain cavity placement area has a second fin area, and the lower side of the semiconductor laser chip placement area has a first fin area, and the length of the fins in the first fin area extending downward is more than twice the length of the fins in the second fin area extending downward. A pipeline is buried in the bottom plate of the laser tube shell, and a refrigerant flows in the pipeline. The pipeline density in the semiconductor laser chip placement area is P1, and the pipeline density in the optical gain cavity placement area is P2, and P1>P2. The pipeline density can be defined by the ratio of the area of ​​the pipeline projected on the first surface in the predetermined area to the total area of ​​the predetermined area. Of course, the following implementation can also be adopted, in which a pipeline is provided in the semiconductor laser chip placement area, and a refrigerant flows in the pipeline, and no pipeline is provided in the optical gain cavity placement area. Of course, although this can balance the heat dissipation, it will reduce the heat dissipation capacity of the optical gain cavity placement area compared to the previous implementation. Whether it is the first fin area or the second fin area, the heat dissipation fins are formed by multiple parallel sheet structures extending along the first direction, and multiple airflow channels extending along the first direction are formed between the multiple sheet structures.

[0029] That is, the utility model relates to a laser tube shell, which is used to encapsulate a fiber laser or other laser generating components. The lower surface of the bottom plate of the laser tube shell is integrally formed with heat dissipation fins for air cooling (instead of arranging a cold plate on the lower side of the tube shell bottom plate as usual), which can effectively reduce thermal resistance and achieve efficient heat dissipation. Preferably, a refrigerant pipeline can also be buried in the bottom plate of the laser tube shell, and the refrigerant pipeline can be used to circulate phase change refrigerant or refrigerant such as water. When the phase change refrigerant circulates in the pipeline, the pipeline in the bottom plate of the laser tube shell is connected to the refrigerant pipeline of an external compression refrigeration device; when the water refrigerant circulates in the pipeline, the pipeline in the bottom plate of the laser tube shell is connected to the external water supply pipe and drainage pipe; in this way, in addition to the refrigerant taking away heat through the pipeline, the heat on the heat dissipation fins on the lower surface of the body 1 can also be continuously taken away by air cooling. Therefore, the heat conductivity of the non-pipeline area in the cold plate can be effectively utilized and double heat dissipation can be achieved to improve the heat dissipation efficiency. In this way, the tube shell bottom plate is both a refrigerant cooling tube shell and a direct air cooling tube shell.

[0030] like Figure 1 As shown, the utility model includes a laser tube shell bottom plate, which is used to dissipate heat for the laser device. The bottom plate includes a plate-shaped body 1, which is made of a heat-conducting material. The first surface (upper surface) of the body 1 is used to receive the heat generated by the heat source and conduct it downward. In order to improve the heat dissipation efficiency, a pipe is buried in the heat dissipation bottom plate (see Figure 1 , 2 6) A pipe is provided in the heat dissipation base plate, and a refrigerant can flow through the pipe. Specifically, when water cooling is adopted, water refrigerant flows through the pipe in the heat dissipation base plate. When a compression cooling solution is adopted, a phase change refrigerant flows through the pipe in the heat dissipation base plate.

[0031] This solution can solve some problems of the solution of cooling only through the refrigerant in the pipe. Among them, since only the refrigerant circulating in the refrigerant pipe is the final way for heat to flow out, the efficiency of introducing heat from the heat dissipation base plate into the refrigerant pipe is crucial. Therefore, the more comprehensive the distribution area of ​​the refrigerant pipe in the heat dissipation base plate, the greater the density of the refrigerant pipe, and the larger the surface area, the higher the heat dissipation efficiency. Since the refrigerant pipe only bends and extends in the area inside the heat dissipation base plate, it is not necessary to cover the entire transverse cross-section of the heat dissipation base plate. The setting of refrigerant pipes with too high density is not only costly but also reduces the mechanical strength of the entire heat dissipation base plate. In addition, refrigerant pipes that are too long will also increase the resistance to refrigerant transportation. Therefore, preferably, heat dissipation fins are formed on the second surface (lower surface) of the main body 1. In addition to the refrigerant taking away heat through the pipe, the heat on the heat dissipation fins on the lower surface of the main body 1 can also be continuously taken away by air cooling. Thereby, the thermal conductivity of the non-pipeline area in the heat dissipation base plate can be effectively utilized and double heat dissipation can be achieved to improve the heat dissipation efficiency. In order to reduce the thermal resistance of air cooling and improve the heat dissipation capacity of air cooling, preferably, the body 1 and the heat dissipation fins are integrally formed, and the body 1 and the heat dissipation fins are made of thermally conductive materials, especially the body 1 and the heat dissipation fins are made of high thermal conductivity materials, such as high thermal conductivity aluminum (including ordinary aluminum and special doped aluminum alloys, etc.), graphene materials, and fans and other components should be set on the lower side or side of the heat dissipation fins to drive the airflow and increase the wind speed; in order to increase the heat dissipation efficiency of air cooling, see Figure 4 The heat dissipation fins are generally formed of a plurality of parallel sheet structures extending along a first direction, and a plurality of air flow channels extending along the first direction are formed between the plurality of sheet structures. Figure 5 The fan-driven airflow can flow along multiple airflow channels extending in the first direction without being blocked, so the airflow speed is very high and the heat dissipation surface area is large, which can greatly increase the speed at which the airflow carries away heat.

[0032] The technical principle of the present invention is described above in combination with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the protection scope of the present invention in any way. Based on the explanations here, technicians in this field can think of other specific implementation methods of the present invention without creative work, and these methods will fall within the protection scope of the present invention.

Claims

1. A fiber laser tube shell, comprising a bottom plate of the laser tube shell, the bottom plate supports a laser generating assembly; the laser generating assembly comprises a plurality of semiconductor laser chips and an optical gain cavity portion; the bottom plate of the laser tube shell comprises a semiconductor laser chip placement area and an optical gain cavity placement area, and the optical gain cavity portion and the semiconductor laser chip are packaged on the bottom plate of the laser tube shell; At least one semiconductor chip packaging top plate is arranged on the semiconductor chip placement area; At least one semiconductor chip package top plate and bottom plate cooperate to form a package for a plurality of semiconductor laser chips; the characteristic is that: the bottom plate of the laser tube shell includes a plate-shaped body, the first surface of the body is used to receive the heat generated by the heat source and conduct it downward, and the heat dissipation fins are formed on the second surface of the body, which can take away the heat on the heat dissipation fins on the lower surface of the body by air cooling, and the body and the heat dissipation fins are integrally formed, and the body and the heat dissipation fins are both made of heat-conducting materials.

2. According to claim 1, a fiber laser tube shell has a pipeline buried in the bottom plate of the laser tube shell, and a refrigerant flows in the pipeline.

3. According to claim 2, a fiber laser tube shell, the pipeline is located in the body, and water refrigerant or phase change refrigerant flows in the pipeline in the body; the body and the heat dissipation fins are both made of aluminum or graphene.

4. According to claim 1, a fiber laser shell, a plurality of semiconductor laser chips are divided into N semiconductor laser chip groups, each semiconductor laser chip group outputs a pump laser together, and multiple pump lasers enter the gain cavity fiber after being combined by spatial photosynthesis or a beam combiner, and has N semiconductor chip packaging top plates, each semiconductor chip packaging top plate is used to cover a corresponding semiconductor laser chip group, that is, N semiconductor chip packaging top plates and the laser shell bottom plate cooperate to package N semiconductor laser chip groups, and N is an integer greater than 1.

5. According to the fiber laser shell of claim 1, at least one semiconductor laser chip is mounted on the surface of the semiconductor laser chip placement area and is in thermal contact with the semiconductor laser chip, an active optical fiber is mounted on the surface of the gain cavity placement area and is in thermal contact with the active optical fiber, at least one semiconductor laser chip outputs pump light through an output pigtail, the pump light is coupled into the active optical fiber through a coupler, and a fiber laser is generated and output through the active optical fiber.

6. According to a fiber laser tube shell of claim 1, a second fin area is provided at the lower side of the gain cavity fiber placement area, a first fin area is provided at the lower side of the semiconductor laser chip placement area, and a length of the fins of the first fin area extending downward is twice or more than a length of the fins of the second fin area extending downward.

7. According to the fiber laser tube shell of claim 1, an optical gain cavity packaging top plate is arranged on the gain cavity fiber placement area; The optical gain cavity packaging top plate and the laser tube shell bottom plate cooperate to form a package for the gain cavity optical fiber; The gain cavity optical fiber is a closed-loop coiled structure in which multiple arc segments are connected in sequence.

8. A fiber laser tube shell according to claim 1, wherein the bottom plate of the tube shell adopts a solid structure.

9. According to claim 1, a fiber laser tube shell has pipes buried in the bottom plate of the laser tube shell, refrigerant flows in the pipes, the pipe density in the semiconductor laser chip placement area is P1, the pipe density in the gain cavity fiber placement area is P2, and P1>P2.

10. According to the optical fiber laser tube shell of claim 2, when a phase change refrigerant flows through the pipeline, the pipeline in the bottom plate of the laser tube shell is connected to the refrigerant pipeline of an external compression refrigeration device; when a water refrigerant flows through the pipeline, the pipeline in the bottom plate of the laser tube shell is connected to an external water supply pipe and a drainage pipe.

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