Cladding light stripper and method of making same, fiber laser

Abstract

The application discloses a cladding light stripper and a manufacturing method thereof and an optical fiber laser, and relates to the technical field of cladding light strippers, wherein the cladding light stripper comprises a double-cladding optical fiber assembly and a triple-cladding bare fiber; the double-cladding optical fiber assembly comprises two double-cladding optical fibers; each double-cladding optical fiber comprises a double-cladding bare fiber and a coating layer which are sequentially sleeved from inside to outside; the double-cladding bare fiber extends out of the coating layer; the triple-cladding bare fiber is in a plurality of sections; the plurality of triple-cladding bare fibers are sequentially fused to form a main body; the two double-cladding optical fibers are respectively fused to two ends of the main body through the double-cladding bare fibers; and the main body is provided with a stripper. The cladding light stripper can be manufactured by using the plurality of triple-cladding bare fibers to manufacture the stripper on the premise that the original advantages of the double-cladding optical fiber and the triple-cladding bare fiber are maintained; thus, the cladding light stripper can prevent a local hot spot from being generated in a certain triple-cladding bare fiber due to long-time bearing of high power, and the ability of the cladding light stripper to strip cladding light is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cladding light strippers, and particularly relates to a cladding light stripper and a manufacturing method thereof and a fiber laser. BACKGROUND

[0002] In the process of laser transmission, the cladding of the optical fiber will accumulate a large amount of cladding light due to the reasons such as fiber fusion loss, mode field mismatch, incomplete absorption of pump light by gain optical fiber, amplified spontaneous emission light, etc. If the cladding light is allowed to follow the laser output, it will not only affect the beam quality of the laser light source, but also cause the heating of the output fiber of the laser, and even direct damage in severe cases.

[0003] Therefore, it is necessary to add a cladding light stripper in the fiber laser. The cladding light stripper is a core device for stable operation of the fiber laser, which plays a role in stripping the cladding light and optimizing the beam quality. The design principle is to destroy the total reflection condition of the cladding light, so that the cladding light is released from the cladding of the optical fiber, and the stripped cladding light is absorbed by the metal shell and converted into heat. At present, the cladding light stripper will have local hot spots when in use, and it cannot strip too much cladding light, which is not conducive to the filtering of the cladding light of the super high power laser. SUMMARY

[0004] The main purpose of the present application is to provide a cladding light stripper and a manufacturing method thereof and a fiber laser, which aims to solve the technical problem that the cladding light stripper in the prior art has local hot spots, thereby causing the cladding light to be unable to be stripped too much.

[0005] To achieve the above-mentioned purpose, according to one aspect of the present application, a cladding light stripper is provided, comprising:

[0006] A double-clad fiber assembly comprises two double-clad fibers, each of which comprises a double-clad bare fiber and a coating layer which are sequentially sleeved from inside to outside, and the double-clad bare fiber extends out of the coating layer.

[0007] A triple-clad bare fiber, the number of which is multiple segments, is sequentially fused to form a main body, and the two double-clad fibers are respectively fused to the two ends of the main body through the double-clad bare fiber, and a stripper is formed on the main body.

[0008] In an embodiment, the number of the triple-clad bare fiber is three segments.

[0009] In an embodiment, the triple-clad bare fiber comprises a first core, an inner cladding and a first outer cladding which are sequentially sleeved from inside to outside, and the outer diameters of the inner cladding of each triple-clad bare fiber are different, and the three triple-clad bare fibers are sequentially fused from large to small according to the outer diameters of the inner cladding.

[0010] In an embodiment, the double-clad bare fiber comprises a second core and a second outer cladding which are sleeved from inside to outside in sequence, and the diameter of the first core is equal to that of the second core.

[0011] In an embodiment, the outer diameter of the first outer cladding is equal to that of the second outer cladding.

[0012] In an embodiment, the core numerical aperture of the double-clad bare fiber is equal to that of the triple-clad bare fiber.

[0013] According to another aspect of the present application, the present application further provides a fiber laser, which comprises the cladding light stripper as described above.

[0014] According to another aspect of the present application, the present application further provides a manufacturing method of a cladding light stripper, which is applied to the cladding light stripper as described above, and comprises the following steps:

[0015] manufacturing the double-clad optical fibers with two sections of the double-clad bare fiber extending out of the coating layer;

[0016] manufacturing the main body from the triple-clad bare fiber;

[0017] fusing the double-clad bare fiber of each of the two sections of the double-clad optical fibers to two ends of the main body, respectively;

[0018] manufacturing the stripper on the main body.

[0019] In an embodiment, the manufacturing of the double-clad optical fibers with two sections of the double-clad bare fiber extending out of the coating layer comprises the following steps:

[0020] taking one section of the double-clad optical fiber assembly;

[0021] stripping the coating layer of the middle part of the double-clad optical fiber assembly to expose the double-clad bare fiber, and cleaning the double-clad bare fiber;

[0022] cutting the double-clad bare fiber by using a fiber cutter to form two sections of the double-clad optical fibers.

[0023] In an embodiment, the manufacturing of the main body comprises the following steps:

[0024] taking three sections of the triple-clad optical fibers, stripping the coating layer of each of the triple-clad optical fibers completely to form three sections of the triple-clad bare fibers, and cleaning the triple-clad bare fibers;

[0025] cutting two sides of each of the triple-clad bare fibers by using a fiber cutter;

[0026] The three segments of the three cladding bare fibers are fused together by an optical fiber fusion splicer to form the main body.

[0027] In the above scheme, the cladding light stripper includes a double-cladding fiber assembly and three cladding bare fibers. The double-cladding fiber assembly includes two segments of double-cladding fibers, each of which includes a double-cladding bare fiber and a coating layer successively sleeved from inside to outside, and the double-cladding bare fiber extends out of the coating layer. The number of the three cladding bare fibers is multiple segments, and the multiple segments of the three cladding bare fibers are sequentially fused to form a main body. The two segments of the double-cladding fibers are fused to the two ends of the main body through the double-cladding bare fibers, and the stripper is formed on the main body. Specifically, a relatively long double-cladding fiber, i.e., the double-cladding fiber assembly, is taken. The coating layer of the middle part of the double-cladding fiber assembly is stripped, and then the exposed double-cladding bare fiber is cleaned. The double-cladding bare fiber is cut by an optical fiber cutting knife, so that two segments of double-cladding fibers extending out of the coating layer are formed. Then, multiple segments of three cladding bare fibers are taken. The coating layer of each three cladding bare fiber is taken out to expose the internal three cladding bare fiber. Then, the three cladding bare fiber is cleaned, and the three cladding bare fiber is cut on both sides to make the two sides of the three cladding bare fiber neat. The three segments of the three cladding bare fibers are sequentially fused to form a main body. The two segments of the double-cladding fibers are fused to the two ends of the main body through the double-cladding bare fibers. Finally, the stripper is made on the surface of the main body by laser marking or chemical etching or a combination of the two. When the cladding light stripper is used, the optical signal enters from the double-cladding fiber at one end. At this time, the optical signal mainly propagates in the core, but a part of the light may exist in the form of cladding light in the inner cladding of the double-cladding bare fiber, and then is transmitted to the main body part. The main body part is formed by fusing multiple segments of three cladding bare fibers. In this way, the refractive path of the cladding light changes, and the cladding light enters the outer cladding of the three cladding bare fiber or is scattered out, realizing the stripping of the cladding light. In the present application, multiple segments of three cladding bare fibers are used to make the stripper, which can prevent a certain segment of the three cladding bare fiber from generating a local hot spot due to long-term bearing of high power, thereby greatly improving the ability of the cladding light stripper to strip the cladding light. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and other drawings can also be obtained according to the structures shown in these drawings without any creative labor.

[0029] Figure 1 The structure schematic diagram of an embodiment of the cladding light stripper provided by the present application;

[0030] Figure 2 The structure schematic diagram of an embodiment of the main body provided by the present application;

[0031] Figure 3 A flow chart of a manufacturing method of a cladding light stripper according to a first embodiment of the present application;

[0032] Figure 4 A flow chart of a manufacturing method of a cladding light stripper according to a second embodiment of the present application;

[0033] Figure 5 A flow chart of a manufacturing method of a cladding light stripper according to a third embodiment of the present application.

[0034] Brief Description of the Drawings:

[0035] 100, cladding light stripper; 1, double-clad fiber assembly; 11, double-clad fiber; 111, double-clad bare fiber; 111a, second core; 111b, second outer cladding; 112, coating layer; 2, triple-clad bare fiber; 21, first core; 22, inner cladding; 23, first outer cladding; 3, main body.

[0036] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0038] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture, and if the certain posture changes, the directional indications also change accordingly.

[0039] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, if "and / or" or "and / or" appears throughout the text, it means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor in the protection scope required by the present application.

[0040] Due to the reasons such as fiber fusion loss, mode field mismatch, gain fiber not fully absorbing pump light, amplified spontaneous emission light, etc., in the process of laser transmission, the cladding of the optical fiber will accumulate a large amount of cladding light. If it is left to follow the laser output, not only will it affect the beam quality of the laser source, but also it will cause the output tail fiber of the laser to heat up, and in severe cases it will be directly damaged.

[0041] Therefore, it is necessary to add a cladding light stripper in the fiber laser. The cladding light stripper is the core device for stable operation of the fiber laser, which plays a role in stripping the cladding light and optimizing the beam quality. The design principle is to destroy the total reflection condition of the cladding light, so that the cladding light is released from the cladding of the optical fiber, and the stripped cladding light is absorbed by the metal shell and converted into heat. At present, the cladding light stripper is made of double-clad fiber. Although the cladding light stripper made of double-clad fiber can strip the cladding light, the efficiency is low, and local hot spots will appear during use, and too much cladding light cannot be stripped, which is not conducive to the filtering of the cladding light of the ultra-high power laser. In order to solve this problem, the applicant has studied to use a three-clad fiber to make a cladding light stripper. Although the efficiency of stripping the cladding light is improved, the problem of local hot spots still exists during use, and the manufacturing process of the three-clad fiber made by fusion is more complex and the cost is higher, which may increase the overall cost of the laser system. In order to further eliminate local hot spots and control the cost as much as possible, the applicant has studied and designed a new cladding light stripper.

[0042] To achieve the above-mentioned purpose, see Figure 1 and Figure 2According to an aspect of the present application, the present application provides a cladding light stripper 100, comprising a double-cladding fiber assembly 1 and a three-cladding bare fiber 2, the double-cladding fiber assembly 1 comprises two double-cladding fibers 11, each double-cladding fiber 11 comprises a double-cladding bare fiber 111 and a coating layer 112 which are sleeved from inside to outside in turn, and the double-cladding bare fiber 111 extends out of the coating layer 112; the three-cladding bare fiber 2 is in multiple segments, and the multiple segments of the three-cladding bare fiber 2 are sequentially fused to form a main body 3, and the two double-cladding fibers are fused to the two ends of the main body 3 through the double-cladding bare fibers 111 respectively, and the main body 3 is formed with a stripper. Specifically, a longer double-cladding fiber 11, that is, the double-cladding fiber assembly 1 described above, is taken, the coating layer 112 of the middle part of the double-cladding fiber assembly 1 is stripped, then the exposed double-cladding bare fiber 111 is cleaned, and the double-cladding bare fiber 111 is cut off by a fiber cutting knife, so that the double-cladding fiber 11 with the double-cladding bare fiber 111 extending out of the coating layer 112 is formed, then multiple three-cladding fibers are taken, the coating layer 112 of each three-cladding fiber is taken out to expose the internal three-cladding bare fiber 2, then the three-cladding bare fiber 2 is cleaned and cut on both sides to make the three-cladding bare fiber 2 neat on both sides, the three segments of the three-cladding bare fiber 2 are sequentially fused to form the main body 3, then the two double-cladding fibers 11 are fused to the two ends of the main body 3 through the double-cladding bare fibers 111 respectively, and finally the stripper is made on the surface of the main body 3 by laser marking or chemical corrosion or a combination of the two; when the cladding light stripper 100 is used, the optical signal enters from the double-cladding fiber 11 at one end, at this time, the optical signal mainly propagates in the core, but a part of the light may exist in the form of cladding light in the inner cladding layer 22 in the double-cladding bare fiber 111, and then is transmitted to the main body 3 part, the main body 3 part is formed by fusing the multiple segments of the three-cladding bare fiber 2, so that the refractive path of the cladding light changes, the cladding light enters the outer cladding layer of the three-cladding bare fiber 2 or is scattered out, and the stripping of the cladding light is realized; in the embodiment, the stripper is made of multiple segments of the three-cladding bare fiber 2, so that the local hot spot caused by a segment of the three-cladding bare fiber 2 due to long-time bearing of high power can be prevented, and the ability of the cladding light stripper 100 to strip the cladding light is greatly improved.

[0043] Referring to Figure 1 and Figure 2In an embodiment, the number of the three-clad bare fibers 2 is three. The sequential fusion of the three three-clad bare fibers can achieve multi-stage optical stripping. Each three-clad bare fiber can further remove the cladding light, thereby improving the cladding light stripping efficiency. By optimizing the parameters of each three-clad bare fiber, a more precise optical stripping effect can be achieved, ensuring that the purity of the final output optical signal is very high. The design of the three three-clad bare fibers can better disperse heat and prevent local overheating, thereby improving the thermal stability of the system. Effective heat management helps to prolong the service life of the optical fiber device and improve the reliability and long-term stability of the system. If more three-clad bare fibers 2 are sequentially fused, the cladding light stripping efficiency can be further improved, but the number of fusion points will also increase, which means that the overall structure is more complex and the manufacturing difficulty is higher. The three three-clad bare fibers 2 in this embodiment can reduce the manufacturing difficulty while ensuring the cladding light stripping efficiency.

[0044] Referring to Figure 1 and Figure 2 In an embodiment, the three-clad bare fiber 2 includes a first core 21, an inner cladding 22, and a first outer cladding 23, which are sequentially sleeved from inside to outside. The outer diameters of the inner cladings 22 of each three-clad bare fiber 2 are different. The three three-clad bare fibers 2 are sequentially fused from large to small according to the outer diameters of the inner claddings 22. The three three-clad bare fibers 2 are sequentially fused from large to small according to the outer diameters of the inner claddings 22, forming a gradually changing structure. The outer diameter of the inner cladding 22 of the first three-clad bare fiber 2 is the largest. When the optical signal propagates in this section, the propagation path of the cladding light is relatively wide and easy to control and manage. The outer diameter of the inner cladding 22 of the second three-clad bare fiber 2 is smaller. When the optical signal propagates in this section, the propagation path of the cladding light gradually narrows and begins to be more restricted. The outer diameter of the inner cladding 22 of the third three-clad bare fiber 2 is the smallest. When the optical signal propagates in this section, the propagation path of the cladding light further narrows and is more easily removed or scattered. The structure in this embodiment can more effectively remove unnecessary cladding light and further improve the cladding light stripping efficiency by gradually reducing the outer diameter of the inner cladding 22.

[0045] Referring to Figure 1 and Figure 2 In an embodiment, the double-clad bare fiber 111 includes a second core 111a and a second outer cladding 111b, which are sequentially sleeved from inside to outside. The diameters of the first core 21 and the second core 111a are equal. The diameters of the first core 21 and the second core 111a are equal, which means that the diameters of the double-clad bare fiber 111 and the three-clad bare fiber 2 in the core part are the same. This can ensure that the transmission characteristics of the optical signal in the core remain consistent.

[0046] Referring to Figure 1 and Figure 2In an embodiment, the outer diameter of the first outer cladding 23 is equal to the outer diameter of the second outer cladding 111b. The outer diameter of the second outer cladding 111b in the double-clad bare fiber 111 and the outer diameter of the first outer cladding 23 in the triple-clad bare fiber 2 are set to the same size, so that the quality of the fusion joint can be ensured during the fusion of the double-clad bare fiber 111 and the triple-clad bare fiber 2, and the effective transmission of the optical signal is ensured while the loss and reflection are minimized.

[0047] Referring to Figure 1 and Figure 2 In an embodiment, the core numerical aperture of the double-clad bare fiber 111 is equal to the core numerical aperture of the triple-clad bare fiber 2. The core numerical aperture is an important parameter of the optical fiber, which describes the ability of the optical fiber to accept and transmit light. The size of the numerical aperture directly affects the coupling efficiency, transmission mode and transmission performance of the optical fiber. In this embodiment, the core numerical aperture of the double-clad bare fiber 111 is set to be equal to the core numerical aperture of the triple-clad bare fiber 2, which ensures that the transmission characteristics of the optical signal between different double-clad bare fibers 111 and triple-clad bare fibers 2 remain consistent, reducing the loss and reflection of the fusion joint.

[0048] According to another aspect of the present application, the present application also provides a fiber laser, which comprises the cladding light stripper 100 described above. Since the fiber laser comprises all the embodiments of the above-described fiber laser, it at least has all the beneficial effects brought by all the above-described embodiments, which will not be repeated here.

[0049] According to another aspect of the present application, referring to Figure 3 , Figure 3 The present application also provides a manufacturing method of the cladding light stripper 100, which is applied to the cladding light stripper 100 described above. The manufacturing method of the cladding light stripper 100 comprises the following steps:

[0050] S1, manufacturing two segments of the double-clad bare fiber 111 extending out of the coating layer 112;

[0051] First, determine the length of the coating layer 112 that needs to be stripped, and mark the position on the double-clad optical fiber 11. Then, carefully strip the coating layer 112 of the optical fiber according to the marked position using an optical fiber stripper, and expose the internal double-clad bare fiber 111. The stripping intensity should be moderate to avoid damaging the internal fiber core.

[0052] S2, manufacturing the main body 3 from the triple-clad bare fiber 2;

[0053] Select the three cladding optical fiber, and then use the optical fiber stripper to carefully remove the coating layer 112 of the three cladding optical fiber according to the marked position, expose the internal three cladding bare fiber 2, and then make the main body 3 through the three cladding bare fiber 2.

[0054] S3, the double cladding bare fiber 111 of the two sections of double cladding optical fiber 11 is respectively fused to the two ends of the main body 3;

[0055] The double cladding bare fiber 111 of the two sections of double cladding optical fiber is respectively cladded to the two ends of the main body 3 through the fusion splicer.

[0056] S4, make a stripper on the main body 3.

[0057] Make a stripper on the outer cladding of the main body 3, which can be laser marking or chemical etching or a combination of the two.

[0058] In this embodiment, first determine the length of the coating layer 112 that needs to be stripped, and mark on the double cladding optical fiber 11, then use the optical fiber stripper to carefully remove the coating layer 112 of the optical fiber according to the marked position, expose the internal double cladding bare fiber 111, select the three cladding optical fiber, then use the optical fiber stripper to carefully remove the coating layer 112 of the three cladding optical fiber according to the marked position, expose the internal three cladding bare fiber 2, then make the main body 3 through the three cladding bare fiber 2, then fuse the two sections of double cladding optical fiber 11 to the two ends of the main body 3 through the double cladding bare fiber 111, and finally make a stripper on the surface of the main body 3 by laser marking or chemical etching or a combination of the two; When using the cladding light stripper 100, the optical signal enters from the double cladding optical fiber 11 at one end, at this time, the optical signal mainly propagates in the core, but a part of the light may exist in the inner cladding 22 of the double cladding bare fiber 111 in the form of cladding light, and then is transmitted to the main body 3 part, which is made of multiple three cladding bare fibers 2, so that the refractive path of the cladding light changes, and the cladding light enters the outer cladding of the three cladding bare fiber 2 or is scattered out, realizing the stripping of the cladding light. By fusing the double cladding optical fiber 11 and the three cladding bare fiber 2 to make the cladding light stripper 100, the overall performance and application range of the cladding light stripper 100 can be further improved while maintaining the original advantages of the double cladding optical fiber 11 and the three cladding bare fiber 2.

[0059] Referring to Figure 4 , Figure 4 The flowchart of the second embodiment of the cladding light stripper 100 is shown in the method for making the cladding light stripper 100, in an embodiment, making the double cladding optical fiber 11 with two sections of double cladding bare fiber 111 extending out of the coating layer 112 includes the following steps:

[0060] S11, take a section of double cladding optical fiber assembly 1;

[0061] Select a long double-clad optical fiber 11, which is equivalent to a double-clad optical fiber assembly 1, and then mark the middle part of the double-clad optical fiber.

[0062] S12, strip the coating layer 112 of the middle part of the double-clad optical fiber assembly 1 to expose the double-clad bare fiber 111, and clean the double-clad bare fiber 111;

[0063] The operator carefully removes the coating layer 112 of the middle part of the double-clad optical fiber 11 by using the optical fiber stripper according to the mark, exposes the internal double-clad bare fiber 111 of the middle part of the double-clad optical fiber 11, and then cleans the double-clad bare fiber 111 to prevent dust or impurities from affecting subsequent operations.

[0064] S13, cut the double-clad bare fiber 111 by using an optical fiber cutting knife to form two double-clad optical fibers 11.

[0065] After cleaning, the operator cuts the exposed double-clad bare fiber 111 by using an optical fiber cutting knife, and then performs flatness treatment on the cut section.

[0066] In this embodiment, a long double-clad optical fiber 11 is selected, which is equivalent to a double-clad optical fiber assembly 1, and then the middle part of the double-clad optical fiber 11 is marked. The operator carefully removes the coating layer 112 of the middle part of the double-clad optical fiber 11 by using the optical fiber stripper according to the mark, exposes the internal double-clad bare fiber 111 of the middle part of the double-clad optical fiber 11, and then cleans the double-clad bare fiber 111 to prevent dust or impurities from affecting subsequent operations. After cleaning, the operator cuts the exposed double-clad bare fiber 111 by using an optical fiber cutting knife, and then performs flatness treatment on the cut section. Generally, the lengths of the two double-clad optical fibers 11 after cutting are consistent, and the lengths of the double-clad bare fibers 111 extending out are consistent, so that the subsequent production of the cladding light stripper 100 is more beautiful.

[0067] Referring to Figure 5 , Figure 5 The flowchart of the production method of the third embodiment of the cladding light stripper 100 is shown. In an embodiment, the production body 3 includes the following steps:

[0068] S21, take three three-clad optical fibers, completely strip the coating layer 112 of each three-clad optical fiber to form three three-clad bare fibers 2, and clean the three-clad bare fibers 2;

[0069] Three segments of three-clad optical fibers with different outer diameters of inner cladding 22 are selected, the lengths of the three segments of three-clad optical fibers can be equal or not equal, then the coating layer 112 of the three segments of three-clad optical fibers is completely stripped, the three-clad bare fibers 2 in the three segments of three-clad optical fibers are completely exposed, and then the three-clad bare fibers 2 are cleaned.

[0070] S22, using an optical fiber cutting knife to cut the two sides of each segment of three-clad bare fiber 2;

[0071] After the coating layer 112 is completely stripped, the operator uses the optical fiber cutting knife to cut the two sides of each segment of three-clad bare fiber 2, so that the two sides of each segment of three-clad bare fiber 2 are neat, facilitating subsequent fusion.

[0072] S23, the three segments of three-clad bare fibers 2 are fused together by an optical fiber fusion machine to form a main body 3.

[0073] The operator arranges the three segments of three-clad bare fibers 2 in order from large to small according to the outer diameters of the inner cladding 22, and then fuses them in order by the optical fiber fusion machine to form the main body 3.

[0074] In this embodiment, the sequential fusion of the three segments of three-clad optical fibers can achieve multi-stage optical stripping, and each segment of three-clad optical fiber can further remove cladding light, thereby improving the cladding light stripping efficiency. By optimizing the parameters of each segment of three-clad optical fiber step by step, a more precise optical stripping effect can be achieved, ensuring that the purity of the final output optical signal is very high. The design of the three segments of three-clad optical fibers can better disperse heat and prevent local overheating, thereby improving the thermal stability of the system. Effective heat management helps to prolong the service life of the optical fiber device and improve the reliability and long-term stability of the system; The three segments of three-clad bare fibers 2 are fused in order from large to small according to the outer diameters of the inner cladding 22, forming a gradual structure. The outer diameter of the inner cladding 22 of the first segment of three-clad bare fiber 2 is the largest, and the propagation path of the cladding light is relatively wide when the optical signal propagates in this segment, which is easy to control and manage. The outer diameter of the inner cladding 22 of the second segment of three-clad bare fiber 2 is the second largest, and the propagation path of the cladding light gradually narrows when the optical signal propagates in this segment, which is more restricted. The outer diameter of the inner cladding 22 of the third segment of three-clad bare fiber 2 is the smallest, and the propagation path of the cladding light further narrows when the optical signal propagates in this segment, which is more easily removed or scattered. The structure in this embodiment can more effectively remove unnecessary cladding light and further improve the cladding light stripping efficiency by gradually reducing the outer diameter of the inner cladding 22.

[0075] According to the above manufacturing method of the cladding light stripper 100, the following examples are given:

[0076] First step, take a double-clad fiber assembly 1, strip the middle coating layer 112 of the double-clad fiber assembly 1, the stripping length of the coating layer 112 is 3cm, then clean the double-clad bare fiber 111 part and cut the middle double-clad bare fiber 111 region using a fiber cutting knife, divide the double-clad fiber assembly 1 into two, form two double-clad bare fibers 111 extending out of the coating layer 112, wherein the diameter of the second core 111a in the double-clad bare fiber 111 is 50um, the outer diameter of the second outer cladding 111b in the double-clad bare fiber 111 is 360um, and the core numerical aperture is 0.22.

[0077] Second step, take three three-clad fibers, then completely strip the coating layer 112 of the three-clad fibers to form three three-clad bare fibers 2, the diameter of the first core 21 of the three three-clad bare fibers 2 is 50um, the outer diameter of the first outer cladding 23 of the three three-clad bare fibers 2 is 360um, and the outer diameter of the inner cladding 22 of the three three-clad bare fibers 2 is 300um, 150um and 70um respectively, then clean the three three-clad bare fibers 2 and cut the two ends of the three three-clad bare fibers 2 using a fiber cutting knife to make the two ends flat, and the core numerical aperture of the three three-clad bare fibers 2 is 0.22.

[0078] Third step, arrange the three three-clad bare fibers 2 in order from large to small according to the size of the outer diameter of the inner cladding 22, and fuse them together through a fiber fusion machine to form a main body 3.

[0079] Fourth step, fuse the two double-clad fibers 11 through the double-clad bare fibers 111 to the two ends of the main body 3 respectively, the outer diameter of the second outer cladding 111b in the double-clad bare fiber 111 is consistent with the outer diameter of the first outer cladding 23 of the three-clad bare fiber 2, so that the fusion is more stable, the diameter of the second core 111a of the three-clad bare fiber 2 is consistent with the diameter of the first core 21 of the three-clad bare fiber 2, so that the transmission characteristics of the optical signal in the core can be ensured to remain consistent; the core numerical aperture of the double-clad bare fiber 111 is consistent with the core numerical aperture of the three-clad bare fiber 2, so that the transmission characteristics of the optical signal between different double-clad bare fibers 111 and three-clad bare fibers 2 are ensured to remain consistent, reducing the loss and reflection of the fusion point.

[0080] Fifth step, make a stripper on the first outer cladding 23 of the main body 3, the method can be laser marking or chemical etching or a combination of the two, so that when the cladding light enters the main body 3, the cladding light is gradually stripped out of the first outer cladding 23.

[0081] In summary, the stripper is made of multiple three-clad bare fibers 2, which can prevent a certain three-clad bare fiber 2 from generating a local hot spot due to long-term bearing of high power, thereby greatly improving the ability of the cladding light stripper 100 to strip the cladding light.

[0082] The above merely illustrates the embodiments of the present application, and is not intended to limit the patent scope of the present application. Any equivalent structural transformation, direct / indirect application in other related technical fields, or the like, which is made under the technical concept of the present application, and based on the content of the present application specification and drawings, is included in the patent protection scope of the present application.

Claims

1. A cladding light stripper, characterized by, The application relates to a cladding light stripper. The cladding light stripper comprises a double-clad fiber assembly and a triple-clad bare fiber. The double-clad fiber assembly comprises two double-clad fibers, each of which comprises a double-clad bare fiber and a coating layer from inside to outside. The triple-clad bare fiber comprises a first core, an inner cladding and a first outer cladding from inside to outside.

2. The cladding light stripper of claim 1, wherein The outer diameter of the inner cladding of each triple-clad bare fiber is different.

3. The cladding light stripper of claim 1, wherein The triple-clad bare fiber is fused from large to small according to the outer diameter of the inner cladding.

4. The cladding light stripper of claim 3, wherein The triple-clad bare fiber is three segments.

5. The cladding light stripper of claim 1, wherein The double-clad bare fiber comprises a second core and a second outer cladding from inside to outside.

6. A fiber laser, characterized by, The diameter of the first core is equal to that of the second core.

7. A method of manufacturing a cladding light stripper applied to the cladding light stripper according to any one of claims 1 to 5, characterized by, The outer diameter of the first outer cladding is equal to that of the second outer cladding. The core numerical aperture of the double-clad bare fiber is equal to that of the triple-clad bare fiber. The fiber laser comprises the cladding light stripper. The manufacturing method of the cladding light stripper comprises the following steps. Manufacturing the double-clad fiber with two double-clad bare fibers extending out of the coating layer.

8. The method of claim 7, wherein the cladding optical stripper is formed by, Manufacturing the main body with the triple-clad bare fiber. Fusing the double-clad bare fibers of the two double-clad fibers to the two ends of the main body. Manufacturing the stripper on the main body. The manufacturing of the double-clad fiber with two double-clad bare fibers extending out of the coating layer comprises the following steps.

9. The method of claim 7, wherein the cladding optical stripper is formed by, Taking one double-clad fiber assembly. Stripping the coating layer of the middle part of the double-clad fiber assembly to expose the double-clad bare fiber and cleaning the double-clad bare fiber. Cutting the double-clad bare fiber with a fiber cutting knife to form two double-clad fibers. The manufacturing of the main body comprises the following steps. Taking three triple-clad fibers, completely stripping the coating layer of each triple-clad fiber to form three triple-clad bare fibers, and cleaning the triple-clad bare fibers. Cutting the two sides of each triple-clad bare fiber with a fiber cutting knife. Fusing the three triple-clad bare fibers together with a fiber fusion machine to form the main body.

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