A cladding light stripper packaging shell for high-power fiber laser and its application

Abstract

The present invention relates to a cladding light stripper package housing for high-power fiber lasers and its application, belonging to the technical field. The housing comprises a bottom heat sink, a connecting heat sink, and fins. The fins are evenly arranged side by side on the bottom heat sink, a connecting heat sink is coaxially arranged between the fins, and a through hole is provided between the fins and the connecting heat sink. Compared to traditional water-cooled packaging housings, the housing structure of the present invention can more fully utilize forced air cooling for heat dissipation, enhance heat dissipation capacity, and increase power handling capacity.

Description

Technical Field

[0001] The invention relates to a cladding light stripper packaging shell used for a high-power optical fiber laser and application thereof, belonging to the technical field. Background Art

[0002] Compared to traditional solid-state lasers and gas lasers, all-fiber laser systems offer advantages such as superior beam quality, high conversion efficiency, excellent stability, and strong anti-interference capabilities. These advantages give all-fiber laser systems unique advantages in automotive manufacturing, metal processing, cleaning, and rust removal. Fiber lasers, in particular, are particularly useful at lower power levels and at high power levels under specialized conditions. Their compact structure and low risk have gradually attracted the attention of researchers and major manufacturers. However, the biggest challenge with high-power all-fiber laser systems is heat dissipation. In areas prone to high temperatures, cladding strippers are one of the most critical components in high-power fiber lasers due to their effectiveness in stripping cladding light.

[0003] At present, the optical fiber used in high-power all-fiber laser systems is generally double-clad fiber. Since the gain fiber has limited absorption of pump light, there will be residual pump light at its end. At the same time, the imperfect fusion of the fiber fusion point and the back reflection at the fiber output end will further lead to the generation of cladding light. This cladding light will lead to the deterioration of the output laser beam quality and reduce the stability of the entire system. To address this situation, a cladding power stripper (CPS) is needed to strip the cladding light.

[0004] To prevent the stripped cladding light from radiating to other nearby fiber components, potentially posing a safety hazard, and to prevent significant external interference and the accumulation of dust and other debris, which could cause temperature rise and damage the entire system, CPSs in high-power fiber lasers typically feature an external enclosure. This enclosure protects the stripped area from external influences and, secondly, converts the stripped cladding light into heat energy, which is then dissipated through heat conduction, ensuring the stability and reliability of the high-power all-fiber laser system.

[0005] Currently, the CPS in fiber lasers is typically packaged as a quartz glass tube encased in an optical fiber, secured within a rectangular aluminum housing by a fixture. This structure can lead to insufficient heat dissipation when the laser system is operating at high power, causing heat to accumulate in the CPS, creating safety hazards and impacting the reliability and stability of the entire laser system, hindering its long-term stable operation. To ensure the CPS's heat dissipation capacity, and thus the stable operation of the laser system, the housing structure can be modified to enhance heat dissipation.

[0006] Thermal management of CPSs encompasses both the CPS fiber and the CPS package. Currently, most CPS research focuses on thermal management of CPS fibers, specifically improving heat generation and enhancing the power stripping capability of CPSs through innovative and improved stripping processes. For example, multiple optical adhesives with increasing refractive indices are sequentially applied to the fiber cladding along the propagation direction, or the fiber cladding surface roughening is varied from shallow to deep by controlling the chemical etching time, or a combination of both, allowing cladding light to be stripped stepwise according to numerical aperture (NA). This prevents large amounts of power leakage from the CPS over short distances, which can cause localized overheating. Relatively less attention has been paid to thermal management of CPS packages. Most publicly reported CPSs with stripping powers of 100W or above utilize direct water cooling of the package to dissipate heat. However, since circulating cooling water significantly increases the system's volume and mass, it is not compatible with the requirements for miniaturization and water-free cooling of laser light sources. Therefore, research on passive cooling of device packages is imperative. Summary of the Invention

[0007] In response to the shortcomings of the existing technology, the present invention provides a cladding light stripper packaging shell for high-power fiber lasers. Compared with traditional water-cooled packaging shells, the shell structure of the present invention can more fully utilize forced air cooling for heat dissipation, enhance the heat dissipation capacity, and increase the power handling capacity.

[0008] The present invention also provides an application of a cladding light stripper packaging shell used in the high-power fiber laser.

[0009] The technical solutions of the present invention are as follows:

[0010] A cladding light stripper packaging shell used in a high-power fiber laser includes a bottom heat sink, a connecting heat sink, and fins. The fins are evenly arranged side by side on the bottom heat sink, connecting heat sinks are coaxially arranged between the fins, and through holes are provided between the fins and the connecting heat sinks.

[0011] Preferably, according to the present invention, the bottom heat sink, fins and connecting heat sinks are all made of aluminum or aluminum-based silicon carbide materials. Aluminum material is a commonly used material for packaging shells of various optical fiber devices. It has lower density and cost while ensuring heat dissipation capacity. Aluminum-based silicon carbide material has similar thermal conductivity to aluminum, but higher rigidity. Properties such as thermal expansion coefficient can be adjusted by changing its composition to meet other requirements and can be customized according to needs. Graphene coating is provided on the outer surfaces of the bottom heat sink, fins and connecting heat sink. The thickness of the graphene coating is 0.5 mm, which facilitates uniform temperature distribution and reduces the overall temperature of the shell.

[0012] Preferably, according to the present invention, the fin is a rectangular fin, the fin width is the same as the bottom heat sink width, a plurality of interconnected heat pipes are arranged in parallel inside the fin, the heat pipes are filled with a cooling medium, the cooling medium can be water, the bottom of the heat pipe is the evaporation end, and the top is the condensation end.

[0013] Preferably, according to the present invention, the number of fins is 21, the thickness of the fins is 2 mm, and the radius of the heat pipe is 0.5 mm.

[0014] Preferably, according to the present invention, the bottom heat sink has a thickness of 2 mm, and the bottom heat sink and the fins are integrally formed.

[0015] According to the preferred embodiment of the present invention, the connecting heat sink is a hollow cylinder, which is arranged at the center of the fin. The wall thickness of the connecting heat sink is 2 mm. The connecting heat sink connects each fin structure and disperses the heat converted from the through hole to each fin for heat dissipation.

[0016] Preferably, according to the present invention, the radius of the through hole is 3 mm, the inside of the through hole is painted black and set to a black surface, and the inner surface of the through hole is set to a threaded shape. The through hole can absorb the stripped cladding light, convert the energy in the cladding light into heat energy and cool it down in the form of air cooling through the heat pipe and fin structure.

[0017] Preferably, according to the present invention, the shell is rectangular as a whole, with a length of 110 mm, a width of 30 mm, and a height of 40 mm.

[0018] The application of the cladding light stripper package housing used in the above-mentioned high-power fiber laser is as follows:

[0019] (1) The optical fiber and the cladding light stripper are fixed in the through hole. When in use, the cladding light is stripped and irradiated into the through hole. Then the through hole absorbs the cladding light and converts it into heat energy and transfers it to the connected heat sink. The heat energy is conducted in the connected heat sink and then to the fin structure.

[0020] (2) When the heat is transferred to the fins, the cooling medium at the bottom of the heat pipe evaporates and moves upward along the vertical heat pipe. When it reaches the condensation end above the heat pipe, the heat is reduced due to air cooling, condensation occurs, and the cooling medium falls back to the evaporation end again. This process is repeated many times. While the fins themselves dissipate heat, the heat pipe enhances the overall heat dissipation capacity. The graphene coating can make the temperature field distribution more uniform on the basis of the heat dissipation of the fins, and can further reduce the overall temperature.

[0021] The beneficial effects of the present invention are:

[0022] 1. The present invention provides a cladding light stripper packaging shell for high-power fiber lasers. Compared with traditional water-cooled packaging shells, the shell structure of the present invention can more fully utilize forced air cooling for heat dissipation, enhance heat dissipation capacity, and increase power handling.

[0023] 2. The interior of the through hole of the present invention is blackened, which can enhance the absorption efficiency of the light stripped from the cladding, reduce reflected light, and minimize thermal effects. In addition, the threaded surface can greatly improve the light absorption capacity of the through hole.

[0024] 3. The fins of the present invention are provided with heat pipes. When heat is conducted to the fins, the cooling medium at the bottom of the heat pipes evaporates and moves upward along the vertical heat pipes. When it reaches the condensation end above the heat pipes, the heat is reduced due to air cooling, condensation occurs, and the cooling medium falls back to the evaporation end again. This process is repeated many times. While the fins themselves dissipate heat, the heat pipes further enhance the overall heat dissipation capacity.

[0025] 4. The bottom heat sink, fins and connecting heat sink of the present invention are all made of aluminum or aluminum-based silicon carbide materials. Aluminum material is a commonly used material for the packaging shells of various optical fiber devices. It has lower density and cost while ensuring heat dissipation capacity. Aluminum-based silicon carbide material has similar thermal conductivity to aluminum, but higher rigidity. The thermal expansion coefficient and other properties can be adjusted by changing its composition to meet other requirements and can be customized according to needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] Figure 2 It is a cross-sectional view of the fin of the present invention.

[0028] Figure 3 This is a thermal simulation effect diagram of Example 1 of the present invention.

[0029] Figure numerals: 1. bottom heat sink; 2. connected heat sink; 3. through hole; 4. fin; 5. graphene coating; 6. heat pipe. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to embodiments and accompanying drawings, but is not limited thereto.

[0031] Example 1:

[0032] like Figure 1-2 As shown, this embodiment provides a cladding light stripper packaging shell for high-power fiber lasers, including a bottom heat sink 1, a connecting heat sink 2 and fins 4, wherein the fins 4 are evenly arranged side by side on the bottom heat sink 1, the connecting heat sinks 2 are coaxially arranged between the fins 4, and a through hole 3 is provided between the fins 4 and the connecting heat sink 2.

[0033] The bottom heat sink 1, fins 4 and connecting heat sink 2 are all made of aluminum material, which is a commonly used material for packaging shells of various optical fiber devices. It has lower density and cost while ensuring heat dissipation capacity. The outer surfaces of the bottom heat sink 1, fins 4 and connecting heat sink 2 are all provided with a graphene coating 5. The thickness of the graphene coating 5 is 0.5 mm, which facilitates uniform temperature distribution and reduces the overall temperature of the shell.

[0034] The fin 4 is a rectangular fin, and the width of the fin 4 is the same as that of the bottom heat sink 1. A plurality of interconnected heat pipes 6 are arranged in parallel inside the fin 4. The heat pipe 6 is filled with a cooling medium, which can be water. The bottom of the heat pipe 6 is the evaporation end, and the top is the condensation end.

[0035] The number of fins 4 is 21, the thickness of fins 4 is 2 mm, and the radius of heat pipe 6 is 0.5 mm.

[0036] The bottom heat sink 1 has a thickness of 2 mm, and the bottom heat sink 1 and the fins 4 are integrally formed.

[0037] The connecting heat sink 2 is a hollow cylinder, which is arranged at the center of the fin 4. The thickness of the connecting heat sink 2 is 2 mm. The connecting heat sink connects each fin structure and disperses the heat converted from the through hole to each fin for heat dissipation.

[0038] The radius of the through hole 3 is 3 mm, the inside of the through hole 3 is painted black and set to a black surface, and the inner surface of the through hole 3 is set to a threaded shape. The through hole can absorb the stripped cladding light, convert the energy in the cladding light into heat energy and cool it down in the form of air cooling through the heat pipe and fin structure.

[0039] The shell is rectangular as a whole, with a length of 110mm, a width of 30mm and a height of 40mm.

[0040] The application of the cladding light stripper package housing used in the above-mentioned high-power fiber laser is as follows:

[0041] (1) The optical fiber and the cladding light stripper are fixed in the through hole. When in use, the cladding light is stripped and irradiated into the through hole. Then the through hole absorbs the cladding light and converts it into heat energy and transfers it to the connected heat sink. The heat energy is conducted in the connected heat sink and then to the fin structure.

[0042] (2) When the heat is transferred to the fins, the cooling medium at the bottom of the heat pipe evaporates and moves upward along the vertical heat pipe. When it reaches the condensation end above the heat pipe, the heat is reduced due to air cooling, condensation occurs, and the cooling medium falls back to the evaporation end again. This process is repeated many times. While the fins themselves dissipate heat, the heat pipe enhances the overall heat dissipation capacity. The graphene coating can make the temperature field distribution more uniform on the basis of the heat dissipation of the fins, and can further reduce the overall temperature.

[0043] Under the conditions of cladding light power of 500 watts, ambient temperature of 20 degrees Celsius, and wind speed of 10 meters per second, a simulation experiment was conducted on the cladding light stripper using this embodiment. The thermal effect simulation results are as follows: Figure 3 As shown, Figure 3 The data and heat distribution show that when the cladding light stripper using this embodiment strips 500 watts of cladding light, its maximum temperature is 58.1 degrees Celsius and the minimum temperature is 35.1 degrees Celsius. The temperature of the entire cladding light stripper is relatively uniform, with most of the temperature concentrated around 40 degrees Celsius. The highest temperature is located inside the through-hole, and the lowest temperature is located at the edge of the fin. This situation proves that most of the heat energy is dissipated through the fins by air cooling.

[0044] Compared with conventional cooled cladding light strippers, this embodiment can operate stably at a more suitable temperature at the same lower stripping power. At the same time, this embodiment can operate at a cladding stripping power that conventional cooled cladding light strippers cannot withstand, thereby further improving the maximum output power of the all-fiber structure laser.

[0045] Example 2:

[0046] A cladding light stripper packaging shell for high-power fiber lasers has a structure as described in Example 1, except that the bottom heat sink 1, fins 4, and connecting heat sink 2 are all made of aluminum-based silicon carbide material. The thermal conductivity of aluminum-based silicon carbide material is similar to that of aluminum, but it has higher rigidity. Properties such as the thermal expansion coefficient can be adjusted by changing its composition to meet other requirements, and it can be customized according to needs.

[0047] The above description is merely a description of the preferred embodiment of the present invention and is not to be construed as limiting the scope of the claims. The present invention is not limited to the above embodiment, and variations in the specific structure are permitted. Any variations within the scope of the independent claims of the present invention are also within the scope of protection of the present invention.

Claims

1. A cladding light stripper package shell for high-power fiber laser, characterized in that: It includes a bottom heat sink, a connecting heat sink and fins, wherein the fins are evenly arranged side by side on the bottom heat sink, connecting heat sinks are coaxially arranged between the fins, and through holes are provided between the fins and the connecting heat sinks.

2. The cladding light stripper package for high-power fiber laser according to claim 1, characterized in that: The bottom heat sink, fins and connecting heat sinks are all made of aluminum or aluminum-based silicon carbide materials. The outer surfaces of the bottom heat sink, fins and connecting heat sinks are all provided with a graphene coating with a thickness of 0.5 mm.

3. The cladding light stripper package for a high-power fiber laser according to claim 2, wherein: The fins are rectangular fins, and the fin width is the same as the width of the bottom heat sink. Multiple interconnected heat pipes are arranged in parallel inside the fins. The heat pipes are filled with cooling medium. The bottom of the heat pipe is the evaporation end, and the top is the condensation end.

4. The cladding light stripper package for a high-power fiber laser according to claim 3, wherein: The number of fins is 21, the fin thickness is 2mm, and the heat pipe radius is 0.5mm.

5. The cladding light stripper package shell for high-power fiber laser according to claim 4, characterized in that: The bottom heat sink is 2mm thick, and the bottom heat sink and the fins are integrally formed.

6. The cladding light stripper package shell for high-power fiber laser according to claim 5, characterized in that: The connecting heat sink is a hollow cylinder, which is arranged at the center of the fin and has a wall thickness of 2 mm.

7. The cladding light stripper package for a high-power fiber laser according to claim 6, wherein: The through hole radius is 3 mm, the inside of the through hole is set to a black surface, and the inner surface of the through hole is set to a threaded shape.

8. The cladding light stripper package shell for high-power fiber laser according to claim 7, characterized in that: The shell is rectangular as a whole, with a length of 110mm, a width of 30mm and a height of 40mm.

9. An application of a cladding light stripper package shell for a high-power fiber laser as claimed in claim 8, characterized in that: Here are the steps: (1) The optical fiber and the cladding light stripper are fixed in the through hole. When in use, the cladding light is stripped and irradiated into the through hole. Then the through hole absorbs the cladding light and converts it into heat energy and transfers it to the connected heat sink. The heat energy is conducted in the connected heat sink and then to the fin structure. (2) When the heat is transferred to the fins, the cooling medium at the bottom of the heat pipe evaporates and moves upward along the vertical heat pipe. When it reaches the condensation end above the heat pipe, the heat is reduced due to air cooling, condensation occurs, and the cooling medium falls back to the evaporation end again. This process is repeated many times. While the fins themselves dissipate heat, the heat pipe enhances the overall heat dissipation capacity. The graphene coating can make the temperature field distribution more uniform on the basis of the heat dissipation of the fins, and can further reduce the overall temperature.

Images