A fiber cladding light stripper waste light receiving device

Abstract

The application discloses a waste light receiving device of a fiber cladding light stripper, which comprises a heat-conducting base and an upper cover shell, the upper cover shell is fixedly connected with the heat-conducting base in a top-and-bottom covering mode, and a light-heat conversion cavity is formed in the inside of the upper cover shell, an inner light-heat conversion fin group is arranged in the light-heat conversion cavity, a stripping section of a double-cladding optical fiber of the fiber cladding light stripper is arranged in the light-heat conversion cavity, and two ends of a glass tube of the fiber cladding light stripper are positioned and fixed by the heat-conducting base and the upper cover shell. The waste light receiving device can reduce the number of times that waste light passes through the fiber cladding light stripper again, avoid repeated and continuous heating of the stripping section optical fiber by the waste light, reduce the risk of burning of the optical fiber in the glass tube, meanwhile, the light-heat conversion process can be uniformly carried out in the whole light-heat conversion cavity, and the risk of burning of the front end of the stripper can be reduced due to the fact that local overheating caused by too fast heat accumulation at the front end of the heat-conducting base and the upper cover shell is effectively avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fiber lasers, and particularly relates to a waste light receiving device of a fiber cladding light stripper. BACKGROUND

[0002] Fiber lasers have the advantages of good beam quality, high electro-optical conversion efficiency, compact structure, strong stability, convenient thermal management, etc., and have very wide applications in the fields of industrial advanced processing and manufacturing, national defense, laser communication, wireless energy transmission, medical imaging, etc.

[0003] The fiber cladding light stripper is an important device of a fiber laser, which is used to strip the waste light in the fiber cladding, the back light due to reflection, and the high-order mode signal light due to non-linear effects, and has a significant influence on the running stability and beam quality of the fiber laser. The current manufacturing of the cladding light stripper generally uses methods such as hydrofluoric acid corrosion, sand paste corrosion, and mechanical polishing to roughen and thin the fiber cladding to guide the waste light in the cladding out. The fiber processed in the above manner will lose the coating layer and even a certain thickness of the cladding, making the fiber more fragile. The current common processing scheme is to encapsulate the processed fiber in a glass tube for protection.

[0004] During the operation of the laser, a large amount of waste light in the cladding is concentrated on the extremely short fiber in the stripper and guided out. For a kilowatt or even a megawatt high-power fiber laser, the waste light power stripped on this section of fiber can reach hundreds of watts or even kilowatts. If it is allowed to scatter into the laser, a large amount of heat will be generated rapidly, thereby burning the fiber and even other devices. Currently, an independent metal shell is generally used to encapsulate the waste light, and light-heat conversion is realized by using the metal to absorb light, and the accumulated heat is guided out through the water cooling or air cooling channel in the metal shell.

[0005] Currently, aluminum, copper, iron and other metal materials are generally used to make the heat-conducting shell. These metal materials have a low light absorption efficiency in the range of 0.9 μm-1.1 μm. The waste light that is not absorbed in time will repeatedly refract in the encapsulation shell, repeatedly and continuously heating the fragile fiber in the fiber cladding light stripper. This continuous heat accumulation will increase the risk of burning the fiber cladding light stripper. In addition, the current market fiber cladding light strippers generally have the problem of uneven stripping of the cladding light, i.e. most of the cladding light pours out at the front end of the stripper, which will cause the heat to accumulate too quickly at the front end of the metal encapsulation shell of the fiber cladding light stripper, increase the cooling burden of this position, and cause the cooling system to be difficult to guide the heat accumulated at this position out in time, resulting in uneven temperature distribution in the metal encapsulation, and increasing the risk of burning the front end of the stripper. Therefore, a fiber cladding light stripper waste light receiving device capable of efficiently and uniformly receiving the cladding waste light and guiding out the accumulated heat, and having a simple and compact structure is needed. SUMMARY

[0006] In view of the deficiencies in the prior art, the application provides a waste light receiving device for a fiber cladding light stripper, which can guide the waste light portion led out from the front end of the stripper to the middle or even the rear part between the fins of the light-heat conversion cavity for absorption, so that the light-heat conversion process is uniformly carried out in the entire light-heat conversion cavity, and the risk of burning out the front end of the stripper can be effectively reduced due to the local overheating caused by the rapid heat accumulation at the front end of the heat-conducting base and the upper cover shell.

[0007] A waste light receiving device for a fiber cladding light stripper, comprising a heat-conducting base and an upper cover shell, the upper cover shell is fixedly connected with the heat-conducting base in a top-down manner and forms a light-heat conversion cavity inside, an inner light-heat conversion fin group is arranged in the light-heat conversion cavity, a stripped section of a double-clad optical fiber of the fiber cladding light stripper is arranged in the light-heat conversion cavity, and both ends of a glass tube of the fiber cladding light stripper are positioned and fixed by the heat-conducting base and the upper cover shell.

[0008] As a preferred form of the above technical solution, a light-heat conversion groove one is arranged on the top surface of the heat-conducting base along the length direction, a light-heat conversion fin group one is vertically arranged in the light-heat conversion groove one, fixed grooves one are symmetrically arranged on the top surface of the heat-conducting base at both ends of the light-heat conversion groove one, and a heat-conducting clamping groove is symmetrically arranged on the top surface of the heat-conducting base in parallel with the light-heat conversion groove one.

[0009] As a preferred form of the above technical solution, a light-heat conversion groove two is arranged on the bottom surface of the upper cover shell along the length direction, a light-heat conversion fin group two is vertically arranged in the light-heat conversion groove two, fixed grooves two are symmetrically arranged on the bottom surface of the upper cover shell at both ends of the light-heat conversion groove two, and heat-conducting fins adapted to the heat-conducting clamping groove are symmetrically arranged on the bottom surface of the upper cover shell in parallel with the light-heat conversion groove two.

[0010] As a preferred form of the above technical solution, the light-heat conversion fin group one and the light-heat conversion fin group two are the same in structure and are oppositely arranged, and together form the inner light-heat conversion fin group.

[0011] As a preferred form of the above technical solution, the light-heat conversion fin group one and the light-heat conversion fin group two each comprise a plurality of fin single blocks arranged in parallel, the spacing between adjacent two fin single blocks and the height of the fin single block gradually decrease along the laser transmission direction.

[0012] As a preferred form of the above technical solution, the lower end surface and the upper end surface of the fin single blocks oppositely arranged on the top and bottom are provided with notches of the same size, the length of the notches gradually decreases along the laser transmission direction, and the depth of the notches gradually increases along the laser transmission direction.

[0013] As the preferred technical scheme of the above, the upper cover shell bottom surface is also symmetrically provided with a through hole for connecting the fixed groove and the outside of the upper cover shell.

[0014] As the preferred technical scheme of the above, the upper cover shell is provided with an outer light-heat conversion fin group.

[0015] As the preferred technical scheme of the above, the heat-conducting base and / or the upper cover shell is internally provided with a heat dissipation channel, which is a water-cooling or air-cooling channel.

[0016] As the preferred technical scheme of the above, the heat-conducting base is integrated on a water-cooling disc of the fiber laser, and shares a cooling system with the fiber laser.

[0017] Compared with the prior art, the present application has the following beneficial effects:

[0018] 1. In the waste light receiving device of the fiber cladding light stripper, the heat-conducting base and the upper cover shell form a light-heat conversion cavity, and the fin group structure inside the cavity can make the stripped cladding waste light refract multiple times between the fins, reducing the number of times the waste light passes through the cladding light stripper again. This structure not only increases the contact area between the waste light and the cavity to improve the light-heat conversion efficiency, but also avoids the problem of repeatedly and continuously heating the stripped fiber due to the inability to timely convert the waste light into heat, thereby significantly reducing the risk of burning the fiber inside the glass tube.

[0019] 2. In the waste light receiving device of the fiber cladding light stripper, the fin group inside the light-heat conversion cavity has a special arrangement rule along the signal laser transmission direction of the fiber core, and the shape of the fins also changes along the laser transmission direction. This fin shape and arrangement can guide part of the waste light directed by the front end of the stripper to the middle or even the rear fins of the light-heat conversion cavity for absorption, so that the light-heat conversion process is evenly carried out in the entire light-heat conversion cavity. The fiber cladding light strippers made by various methods currently have a certain degree of uneven stripping problem, and the light energy stripped by the front end of the stripper is often greater than that by the rear end. The structure proposed by the present application can avoid the local overheating caused by the rapid accumulation of heat at the front end of the heat-conducting base and the upper cover shell, thereby reducing the risk of burning the front end of the stripper. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a whole structure schematic diagram of the waste light receiving device of the fiber cladding light stripper.

[0021] Figure 2 It is a basic structure schematic diagram of the fiber cladding light stripper.

[0022] Figure 3 It is a whole structure schematic diagram of the fiber cladding light stripper and the waste light receiving device after assembly.

[0023] Figure 4 An exploded view of the assembled optical fiber cladding stripper and waste light receiving device;

[0024] Figure 5 An isometric view of the heat-conducting base provided by the present invention;

[0025] Figure 6 An isometric view of the upper cover housing provided for this invention (flipped so that the bottom surface faces up);

[0026] Figure 7 Schematic diagram of the working principle of the fin assembly.

[0027] Reference numerals: 1-Heat-conducting base, 11-Photothermal conversion tank one, 12-Photothermal conversion fin group one, 13-Fixing slot one, 14-Heat-conducting slot, 2-Upper cover shell, 21-Photothermal conversion tank two, 22-Photothermal conversion fin group two, 23-Fixing slot two, 24-Heat-conducting fin, 25-Through hole, 26-External photothermal conversion fin group, 3-Fiber cladding stripper, 31-Double-clad fiber, 311-Double-clad section, 312-Stripping section, 32-Glass tube, 4-Notch. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The present invention will now be described in further detail with reference to the accompanying drawings:

[0030] like Figures 1 to 4 The illustrated fiber cladding optical stripper waste light receiving device includes a heat-conducting base 1 and an upper cover housing 2. The upper cover housing 1 and the heat-conducting base 2 are fixedly connected and enclosed to form a photothermal conversion cavity. The photothermal heat exchange cavity is provided with an inner photothermal conversion fin assembly. The stripping section 311 of the double-clad optical fiber 31 of the fiber cladding optical stripper 3 is placed in the photothermal conversion cavity. The two ends of the glass tube 32 of the fiber cladding optical stripper 3 are installed and positioned through the heat-conducting base 1 and the upper cover housing 2.

[0031] Figure 2The basic structure of a fiber cladding light stripper 3 widely used in high-power fiber lasers. The fiber cladding light stripper 3 includes a double-clad fiber 31, an encapsulating glass tube 32, the double-clad fiber 31 includes double-clad sections 311, a stripping section 312, the stripping section 312 is arranged between the double-clad sections 311. The common manufacturing method of the current fiber cladding light stripper 3 is to remove the coating layer and the outer cladding layer of a section of the double-clad fiber 31, and then etch the inner cladding layer by using hydrofluoric acid or putty, and further roughen and thin the inner cladding layer by mechanical polishing to guide out the waste light. The fiber processed in the above manner will lose the coating layer and a certain thickness of the inner cladding layer, making the section of the fiber more fragile. To protect this section of the fiber, the section of the fiber is usually encapsulated in the glass tube by using high-temperature resistant glue or a heating and melting method.

[0032] In the embodiment, the top surface of the heat-conducting base 1 is provided with a light-heat conversion groove 11 in the length direction, and the light-heat conversion groove 11 is vertically provided with a light-heat conversion fin group 12. The top surface of the heat-conducting base 1 is symmetrically provided with a fixing groove 13 at both ends of the light-heat conversion groove 11, and the top surface of the heat-conducting base 1 is symmetrically provided with a heat-conducting slot 14 parallel to the light-heat conversion groove 11, as shown in Figure 5

[0033] In the embodiment, the bottom surface of the upper cover shell 2 is provided with a light-heat conversion groove 21 in the length direction, and the light-heat conversion groove 21 is vertically provided with a light-heat conversion fin group 22. The bottom surface of the upper cover shell 2 is symmetrically provided with a fixing groove 23 at both ends of the light-heat conversion groove 22, and the bottom surface of the upper cover shell 2 is symmetrically provided with a heat-conducting fin 24 adapted to the heat-conducting slot 14 parallel to the light-heat conversion groove 23.

[0034] In the embodiment, the bottom surface of the upper cover shell 2 is also symmetrically provided with a through hole 25 for communication between the fixing groove 23 and the outside of the upper cover shell 2, as shown in Figure 6

[0035] Specifically, after the upper cover shell 2 is placed downward on the heat-conducting base 1, the fixing groove 13 and the fixing groove 23 form a fixing channel for mounting and fixing the fiber cladding light stripper 3, and the through hole 25 on the upper cover shell 2 is used for arranging the optical fibers at both ends of the fiber cladding light stripper 3.

[0036] In addition, when the fiber cladding light stripper 3 is installed, an appropriate amount of high-temperature glue can be coated in the fixing groove 13 and the fixing groove 23, and the two ends of the glass tube 32 are fixed in the fixing channel formed by the fixing groove 13 and the fixing groove 23 through the high-temperature glue, so as to avoid damage to the fiber cladding light stripper 3 due to vibration.

[0037] ​​It is emphasized that the fixed inside the fixed groove one 13 and the fixed groove two 23 is the double-clad segment 311 of the double-clad fiber 31, and the stripping segment 312 is located in the light-heat conversion cavity formed by the light-heat conversion groove one 11 and the light-heat conversion groove two 21, and the two ends of the stripping segment 312 are away from the end position of the fixed channel.

[0038] In the embodiment, the light-heat conversion fin group one 12 and the light-heat conversion fin group two 22 are the same structure and oppositely arranged, and together constitute the inner light-heat conversion fin group.

[0039] In the embodiment, the light-heat conversion fin group one 12 and the light-heat conversion fin group two 22 are both composed of a plurality of parallel arranged fin single blocks, and the spacing between the adjacent two fin single blocks and the height of the fin single block gradually decrease along the laser transmission direction.

[0040] In the embodiment, the lower end surface and the upper end surface of the fin single block oppositely arranged are provided with the same size notch 4, the length of the notch 4 gradually decreases along the laser transmission direction, and the depth gradually increases along the laser transmission direction.

[0041] Specifically, as shown in Figure 7 The fin group structure in the light-heat conversion cavity can make the stripped cladding waste light refract multiple times between the fins, increase the contact area of the waste light with the cavity, compensate for the low absorption efficiency of common materials such as aluminum, copper, and iron for 0.9-1.1 μm wavelength laser, and limit the light-heat conversion process as much as possible between the fins, effectively reducing the number of times the waste light passes through the double-clad fiber again, i.e. reducing the re-heating of the double-clad fiber by the waste light, improving the light-heat conversion efficiency, and significantly reducing the risk of burning the double-clad fiber, especially the stripping segment 312. In addition, the fiber cladding light strippers made by various methods currently have a certain degree of uneven stripping problem, i.e. the light energy stripped by the front end of the stripper is often greater than that by the rear end. The change and arrangement of the fin shape in the two fin groups can guide part of the waste light from the front end of the stripper to the middle and even the rear fins of the light-heat conversion cavity for absorption, so that the light-heat conversion process is evenly carried out in the entire light-heat conversion cavity, avoiding burning the fiber due to local overheating, and reducing the pressure of the cooling system.

[0042] It is emphasized that the notch 4 shape of the fin single block in the light-heat conversion fin group one 12 and the light-heat conversion fin group two 22 includes but is not limited to a rectangle, and the change rule of the fin single block shape will also be optimized according to the notch 4 shape, as long as part of the waste light from the front end of the stripper can be guided to the middle and rear of the light-heat conversion cavity for absorption, and the light-heat conversion process is evenly carried out in the cavity.

[0043] In the embodiment, the upper cover shell 2 is externally provided with an external light-heat conversion fin group 26. The external light-heat conversion fin group 26 is composed of a plurality of fin single blocks which are uniformly and parallelly arranged and have the same structure, for increasing the contact area of the upper cover shell 2 with air and improving the heat dissipation efficiency.

[0044] In the embodiment, the heat-conducting base 1 and the upper cover shell 2 are both made of metal heat-conducting materials. The metal materials include but are not limited to aluminum, copper, iron and the like. The materials of the heat-conducting base 1 and the upper cover shell 2 can be the same or different.

[0045] In the embodiment, the heat-conducting base 1 and / or the upper cover shell 2 is internally provided with a heat dissipation channel, which is a water-cooling or air-cooling channel. Meanwhile, heat can be conducted to other positions of the laser through a heat pipe to be uniformly discharged.

[0046] In the embodiment, the heat-conducting base 1 is integrated on a water-cooling disc of the fiber laser, and shares a cooling system with the fiber laser. The heat dissipation efficiency is improved, the number of external water-cooling pipes is reduced, the risk of cooling liquid leakage is lowered, and most importantly, the volume and weight of the laser are reduced.

[0047] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement and the like within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A waste light receiving device for an optical fiber cladding stripper, characterized in that: It includes a heat-conducting base and an upper cover housing. The upper cover housing is fixedly connected to the heat-conducting base and forms a photothermal conversion cavity inside. The photothermal heat exchange cavity is provided with an inner photothermal conversion fin assembly. The stripping section of the double-clad optical fiber of the optical fiber cladding stripper is placed in the photothermal conversion cavity. The two ends of the glass tube of the optical fiber cladding stripper are installed and positioned through the heat-conducting base and the upper cover housing.

2. The optical fiber cladding stripper waste light receiving device according to claim 1, characterized in that: The top surface of the heat-conducting base is provided with a photothermal conversion groove along the length direction. A photothermal conversion fin assembly is vertically arranged inside the photothermal conversion groove. A fixing groove is symmetrically arranged at both ends of the photothermal conversion groove on the top surface of the heat-conducting base. A heat-conducting slot is symmetrically arranged on the top surface of the heat-conducting base parallel to the photothermal conversion groove.

3. The optical fiber cladding stripper waste light receiving device according to claim 2, characterized in that: The bottom surface of the upper cover housing is provided with a photothermal conversion groove II along the length direction. A photothermal conversion fin assembly II is vertically provided in the photothermal conversion groove II. A fixing groove II is symmetrically provided at both ends of the photothermal conversion groove II on the bottom surface of the upper cover housing. A heat-conducting fin adapted to the heat-conducting slot is symmetrically provided on the bottom surface of the upper cover housing parallel to the photothermal conversion groove II.

4. The optical fiber cladding stripper waste light receiving device according to claim 3, characterized in that: The photothermal conversion fin group one and the photothermal conversion fin group two have the same structure and are arranged opposite to each other, together forming the inner photothermal conversion fin group.

5. The optical fiber cladding stripper waste light receiving device according to claim 4, characterized in that: Both the photothermal conversion fin group one and the photothermal conversion fin group two are composed of multiple parallel fin blocks, and the spacing between two adjacent fin blocks and the height of the fin blocks gradually decrease along the laser transmission direction.

6. The optical fiber cladding stripper waste light receiving device according to claim 5, characterized in that: The lower and upper surfaces of the fin blocks arranged opposite each other have notches of the same size. The length of the notches gradually decreases along the laser transmission direction, while the depth gradually increases along the laser transmission direction.

7. The optical fiber cladding stripper waste light receiving device according to claim 3, characterized in that: The bottom surface of the upper cover housing is also symmetrically provided with through holes for connecting the second fixing groove and the outside of the upper cover housing.

8. A waste light receiving device for an optical fiber cladding stripper according to any one of claims 1-7, characterized in that: The upper cover shell is provided with an external photothermal conversion fin assembly.

9. The optical fiber cladding stripper waste light receiving device according to claim 1, characterized in that: The heat-conducting base and / or the upper cover housing are provided with heat dissipation channels, which are water-cooled or air-cooled channels.

10. The optical fiber cladding stripper waste light receiving device according to claim 1, characterized in that: The heat-conducting base is integrated on the water-cooling plate of the fiber laser and shares a cooling system with the fiber laser.

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