Cladding light stripper, manufacturing method thereof and fiber laser

Abstract

The invention discloses a cladding light stripper, a manufacturing method thereof and an optical fiber laser, and relates to the technical field of cladding light strippers, the cladding light stripper comprises a double-cladding optical fiber assembly and a three-cladding bare fiber, the double-cladding optical fiber assembly comprises two sections of double-cladding optical fibers, each double-cladding optical fiber comprises a double-cladding bare fiber and a coating layer which are sequentially arranged from inside to outside in a sleeved mode, and the three-cladding bare fiber is arranged between the double-cladding bare fiber and the coating layer. The double-cladding bare fiber extends out of the coating layer; the number of the three-cladding bare fibers is multiple sections, the multiple sections of three-cladding bare fibers are sequentially welded to form a main body, the two sections of double-cladding optical fibers are welded to the two ends of the main body through the double-cladding bare fibers respectively, and a stripper is formed on the main body. According to the cladding light stripper, on the premise that the original advantages of a double-cladding optical fiber and a three-cladding bare fiber are kept, multiple sections of three-cladding bare fibers are adopted to manufacture the stripper, so that the situation that a certain section of three-cladding bare fiber bears high power for a long time to generate local hot spots can be prevented, and the cladding light stripping capacity of the cladding light stripper is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cladding light strippers, and in particular to a cladding light stripper and a manufacturing method thereof, and an optical fiber laser. Background Art

[0002] Due to fiber fusion loss, mode field mismatch, incomplete absorption of pump light by gain fiber, amplified spontaneous radiation light and other reasons, a large amount of cladding light will accumulate in the cladding of high-power fiber lasers during laser transmission. If it is left unchecked with the laser output, it will not only affect the beam quality of the laser light source, but also cause the laser output pigtail to heat up, and in severe cases, it will be directly damaged.

[0003] Therefore, it is necessary to add a cladding light stripper to the fiber laser. The cladding light stripper is the core device for the stable operation of the fiber laser. It plays the role of stripping the cladding light and optimizing the beam quality. Its design principle is to destroy the total reflection condition of the cladding light, so that the cladding light is released from the fiber cladding, and the stripped cladding light is absorbed by the metal shell and converted into heat. At present, when the cladding light stripper is used, local hot spots will appear, and too much cladding light cannot be stripped, which is not conducive to the filtering of the cladding light of ultra-high power lasers. Summary of the invention

[0004] The main purpose of the present invention is to propose a cladding light stripper and a manufacturing method thereof, and an optical fiber laser, aiming to solve the technical problem in the prior art that the cladding light stripper has local hot spots, which makes it impossible to strip too much cladding light.

[0005] To achieve the above object, according to one aspect of the present invention, the present invention provides a cladding light stripper, comprising:

[0006] A double-clad optical fiber assembly, the double-clad optical fiber assembly comprising two sections of double-clad optical fibers, each of the double-clad optical fibers comprising a double-clad bare fiber and a coating layer sequentially sheathed from the inside to the outside, the double-clad bare fiber extending out of the coating layer;

[0007] The triple-clad bare fiber has multiple sections, and the multiple sections of the triple-clad bare fiber are fused in sequence to form a main body. The two sections of the double-clad optical fiber are fused to the two ends of the main body respectively through the double-clad bare fiber, and a stripper is formed on the main body.

[0008] In one embodiment, the triple-clad bare optical fiber is three in number.

[0009] In one embodiment, the triple-clad bare fiber includes a first fiber core, an inner cladding, and a first outer cladding which are sequentially arranged from the inside to the outside, the outer diameter of the inner cladding of each of the triple-clad bare fibers is different, and the three sections of the triple-clad bare fiber are sequentially welded according to the outer diameter of the inner cladding from large to small.

[0010] In one embodiment, the double-clad bare fiber includes a second fiber core and a second outer cladding sequentially arranged from the inside to the outside, and the diameters of the first fiber core and the second fiber core are equal.

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

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

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

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

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

[0016] Using the triple-clad bare fiber to make the main body;

[0017] The double-clad bare fibers of the two sections of the double-clad optical fiber are respectively fused to the two ends of the main body;

[0018] A stripper is made on the main body.

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

[0020] Take a section of the double-clad optical fiber assembly;

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

[0022] The double-clad bare fiber is cut by a fiber cleaver to form two sections of the double-clad optical fiber.

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

[0024] Take three sections of triple-clad optical fiber, completely strip the coating layer of each section of the triple-clad optical fiber to form three sections of triple-clad bare fiber, and clean the triple-clad bare fiber;

[0025] Use a fiber cleaver to cut both sides of each section of the triple-clad bare fiber;

[0026] Three sections of triple-clad bare optical fibers are fused together using an optical fiber fusion splicer to form the main body.

[0027] In the above scheme, the cladding light stripper includes a double-clad optical fiber assembly and a triple-clad bare fiber. The double-clad optical fiber assembly includes two sections of double-clad optical fibers. Each double-clad optical fiber includes a double-clad bare fiber and a coating layer sequentially arranged from the inside to the outside, and the double-clad bare fiber extends out of the coating layer. The triple-clad bare fiber is in multiple sections, and the multiple sections of triple-clad bare fibers are fused in sequence to form a main body. The two sections of double-clad optical fibers are respectively fused to the two ends of the main body through the double-clad bare fibers, and a stripper is formed on the main body. Specifically, a long section of double-clad optical fiber, that is, the double-clad optical fiber assembly mentioned above, is taken, the coating layer of the middle part of the double-clad optical fiber assembly is stripped off, and then the exposed double-clad bare fiber is cleaned, and then the double-clad bare fiber is cut with an optical fiber cutter, thus forming a double-clad optical fiber with two sections of double-clad bare fiber extending out of the coating layer, and then multiple sections of triple-clad optical fiber are taken out, the coating layer of each triple-clad optical fiber is removed to expose the inner triple-clad bare fiber, and then the triple-clad bare fiber is cleaned and the two sides of the triple-clad bare fiber are cut to make the two sides of the triple-clad bare fiber neat, and the three sections of triple-clad bare fiber are welded in sequence to form a main body, and then the two sections of double-clad optical fiber are respectively welded to the two ends of the main body through the double-clad bare fiber, and finally laser marking or chemical corrosion is performed. The stripper is made on the surface of the main body by etching or a combination of the two; when the cladding light stripper is used, the optical signal enters from the double-clad optical fiber at one end. At this time, the optical signal is mainly propagated in the core, but a part of the light may exist in the inner cladding of the double-clad bare fiber in the form of cladding light, and then transmitted to the main body. The main body is formed by fusion-splicing multiple sections of three-clad bare fibers, which changes the refraction path of the cladding light, and the cladding light will enter the outer cladding of the three-clad bare fiber or be scattered out, thereby realizing the stripping of the cladding light; in the present invention, multiple sections of three-clad bare fibers are used to make the stripper, which can prevent a certain section of the three-clad bare fiber from generating local hot spots due to long-term high power, thereby greatly improving the ability of the cladding light stripper to strip the cladding light. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0029] Figure 1 A schematic structural diagram of an embodiment of a cladding light stripper provided by the present invention;

[0030] Figure 2 A schematic diagram of the structure of a main body embodiment provided by the present invention;

[0031] Figure 3 It is a schematic flow chart of a method for manufacturing a cladding light stripper according to a first embodiment of the present invention;

[0032] Figure 4 It is a schematic flow chart of a method for manufacturing a cladding light stripper according to a second embodiment of the present invention;

[0033] Figure 5 It is a schematic flow chart of a method for manufacturing a cladding light stripper according to a third embodiment of the present invention.

[0034] Description of Figure Numbers:

[0035] 100. Cladding light stripper; 1. Double-clad optical fiber assembly; 11. Double-clad optical fiber; 111. Double-clad bare fiber; 111a. Second fiber core; 111b. Second outer cladding; 112. Coating layer; 2. Triple-clad bare fiber; 21. First fiber core; 22. Inner cladding; 23. First outer cladding; 3. Main body.

[0036] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that if the embodiments of the present invention 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 status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0039] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0040] Due to fiber fusion loss, mode field mismatch, incomplete absorption of pump light by gain fiber, amplified spontaneous radiation light and other reasons, a large amount of cladding light will accumulate in the cladding of high-power fiber lasers during laser transmission. If it is left unchecked with the laser output, it will not only affect the beam quality of the laser light source, but also cause the laser output pigtail to heat up, and in severe cases, it will be directly damaged.

[0041] Therefore, it is necessary to add a cladding light stripper to the fiber laser. The cladding light stripper is the core device for the stable operation of the fiber laser. It plays the role of stripping the cladding light and optimizing the beam quality. Its design principle is to destroy the total reflection condition of the cladding light, so that the cladding light is released from the fiber cladding, and the stripped cladding light is absorbed by the metal shell and converted into heat. At present, cladding light strippers are made of double-clad optical fiber. Although the cladding light stripper made of double-clad optical fiber can strip the cladding light, the efficiency is low, and there will be local hot spots when in use, and it is impossible to strip too much cladding light, 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 studied the use of three-clad optical fiber to make a cladding light stripper. Although the efficiency of stripping the cladding light is improved, the cladding light stripper will still have the problem of local hot spots during use. In addition, the cladding light stripper made of three-clad optical fiber by fusion splicing has a more complicated manufacturing process and a higher cost, which may increase the overall cost of the laser system. In order to further eliminate local hot spots and control costs as much as possible, the applicant has designed a new cladding light stripper through research.

[0042] To achieve the above purpose, see Figure 1 and Figure 2According to one aspect of the present invention, a cladding light stripper 100 is provided, comprising a double-clad optical fiber assembly 1 and a triple-clad bare fiber 2, the double-clad optical fiber assembly 1 comprising two sections of double-clad optical fibers 11, each of the double-clad optical fibers 11 comprising a double-clad bare fiber 111 and a coating layer 112 sequentially sleeved from the inside to the outside, the double-clad bare fiber 111 extending out of the coating layer 112; the triple-clad bare fiber 2 is in multiple sections, the multiple sections of the triple-clad bare fiber 2 are sequentially fused to form a main body 3, the two sections of double-clad optical fibers are respectively fused to the two ends of the main body 3 through the double-clad bare fiber 111, and a stripper is formed on the main body 3. Specifically, a longer section of double-clad optical fiber 11, that is, the above-mentioned double-clad optical fiber assembly 1, is taken, the coating layer 112 of the middle part of the double-clad optical fiber assembly 1 is stripped off, and then the exposed double-clad bare fiber 111 is cleaned, and then the double-clad bare fiber 111 is cut by an optical fiber cutter, thus forming two sections of double-clad optical fiber 11 with double-clad bare fiber 111 extending out of the coating layer 112, and then multiple sections of triple-clad optical fiber are taken out, and the coating layer 112 of each triple-clad optical fiber is removed to expose the internal triple-clad bare fiber 2, and then the triple-clad bare fiber 2 is cleaned and the two sides of the triple-clad bare fiber 2 are cut to make the two sides of the triple-clad bare fiber 2 neat, and the three sections of triple-clad bare fiber 2 are welded in sequence to form a main body 3, and then the two sections of double-clad optical fiber 11 are respectively welded to the two ends of the main body 3 through the double-clad bare fiber 111, and finally, by laser The stripper is made on the surface of the main body 3 by optical marking or chemical etching or a combination of the two. When the cladding light stripper 100 is used, the optical signal enters from the double-clad 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-clad bare fiber 111 in the form of cladding light, and then transmitted to the main body 3. The main body 3 is formed by fusion-splicing multiple sections of triple-clad bare fibers 2, which changes the refraction path of the cladding light, and the cladding light will enter the outer cladding of the triple-clad bare fiber 2 or be scattered out, thereby realizing the stripping of the cladding light. In this embodiment, multiple sections of triple-clad bare fibers 2 are used to make the stripper, which can prevent a certain section of the triple-clad bare fiber 2 from generating local hot spots due to long-term high power, thereby greatly improving the ability of the cladding light stripper 100 to strip cladding light.

[0043] See also Figure 1 and Figure 2In one embodiment, the number of the three-clad bare fiber 2 is three. The sequential fusion splicing of three sections of three-clad optical fiber can achieve multi-level light stripping, and each section of the three-clad optical fiber can further remove the cladding light, thereby improving the efficiency of cladding light stripping. By optimizing the parameters of each section of the three-clad optical fiber step by step, a more refined light stripping effect can be achieved, ensuring that the purity of the final output optical signal is very high. The design of three sections of three-clad optical fiber can better disperse heat and prevent local overheating, thereby improving the thermal stability of the system. Effective thermal management helps to extend the service life of optical fiber devices and improve the reliability and long-term stability of the system; if more three-clad bare fibers 2 are used for sequential fusion splicing, although the efficiency of cladding light stripping can be further improved, the fusion points will be further increased, which means that the overall structure is more complicated and the manufacturing difficulty is higher. The present embodiment uses three sections of three-clad bare fibers 2 to ensure the efficiency of cladding light stripping and reduce the manufacturing difficulty.

[0044] See also Figure 1 and Figure 2 In one embodiment, the triple-clad bare fiber 2 includes a first fiber core 21, an inner cladding 22, and a first outer cladding 23 which are sequentially arranged from the inside to the outside. The outer diameter of the inner cladding 22 of each triple-clad bare fiber 2 is different. The three sections of triple-clad bare fiber 2 are sequentially welded according to the outer diameter of the inner cladding 22 from large to small. The three sections of three-clad bare fiber 2 are welded in sequence according to the outer diameter of the inner cladding 22 from large to small to form a gradient structure. The outer diameter of the inner cladding 22 of the first section of the 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 section of the three-clad bare fiber 2 is second largest. 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 section of the 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 easier to be removed or scattered. The structural arrangement 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] See also Figure 1 and Figure 2 In one embodiment, the double-clad bare fiber 111 includes a second core 111a and a second outer cladding 111b which are sequentially sleeved from the inside to the outside, and 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 triple-clad bare fiber 2 in the core part are the same, which can ensure that the transmission characteristics of the optical signal in the core remain consistent.

[0046] See also Figure 1 and Figure 2In one 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 be the same size, so that in the process of welding the double-clad bare fiber 111 and the triple-clad bare fiber 2, the quality of the welding point can be guaranteed, and the quality of the welding point ensures the effective transmission of the optical signal while minimizing the loss and reflection.

[0047] See also Figure 1 and Figure 2 In one 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. The core numerical aperture describes the ability of the optical fiber to receive 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 and the core numerical aperture of the triple-clad bare fiber 2 are set to be equal, 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 at the fusion point.

[0048] According to another aspect of the present invention, the present invention further provides a fiber laser, which includes the above-mentioned cladding light stripper 100. Since the fiber laser includes all implementations of all the above-mentioned fiber laser embodiments, it has at least all the beneficial effects brought by all the above-mentioned implementations, which will not be described one by one here.

[0049] According to another aspect of the present invention, see Figure 3 , Figure 3 1 is a flow chart of a method for manufacturing a cladding light stripper 100 according to a first embodiment of the present invention. The present invention further provides a method for manufacturing a cladding light stripper 100. The method for manufacturing a cladding light stripper 100 is applied to the cladding light stripper 100 as described above. The method for manufacturing a cladding light stripper 100 comprises the following steps:

[0050] S1, manufacturing a double-clad optical fiber 11 with two sections of double-clad bare fibers 111 extending out of the coating layer 112;

[0051] First, determine the length of the coating 112 that needs to be stripped and mark it on the double-clad optical fiber 11. Then use a fiber stripper to carefully strip the coating 112 of the optical fiber according to the marked position to expose the inner double-clad bare fiber 111. Pay attention to use moderate force to avoid damaging the inner optical fiber core.

[0052] S2, take the triple-clad bare fiber 2 to make the main body 3;

[0053] A triple-clad optical fiber is selected, and then a fiber stripper is used to carefully strip the coating layer 112 of the triple-clad optical fiber according to the marked position to expose the inner triple-clad bare fiber 2, and then the main body 3 is made through the triple-clad bare fiber 2.

[0054] S3, welding the double-clad bare fibers 111 of the two sections of double-clad optical fibers 11 to the two ends of the main body 3 respectively;

[0055] The double-clad bare fibers 111 of the two sections of double-clad optical fibers are clad-fused to the two ends of the main body 3 through a fusion splicer.

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

[0057] The stripper is made on the outer cladding of the main body 3 by laser marking or chemical etching or a combination of the two.

[0058] In this embodiment, the length of the coating layer 112 to be stripped is first determined, and a mark is made on the double-clad optical fiber 11. Then, a fiber stripper is used to carefully strip the coating layer 112 of the optical fiber according to the marked position to expose the double-clad bare fiber 111 inside. A triple-clad optical fiber is selected, and then a fiber stripper is used to carefully strip the coating layer 112 of the triple-clad optical fiber according to the marked position to expose the triple-clad bare fiber 2 inside. Then, a main body 3 is made by using the triple-clad bare fiber 2, and then two sections of the double-clad optical fiber 11 are fused to the two ends of the main body 3 respectively through the double-clad bare fiber 111. Finally, a stripper is made on the surface of the main body 3 by laser marking or chemical etching or a combination of the two. When the cladding optical stripper 10 is used, At 0, the optical signal enters from the double-clad 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-clad bare fiber 111 in the form of cladding light, and then be transmitted to the main body 3. The main body 3 is formed by fusion-splicing multiple sections of triple-clad bare fiber 2, which changes the refraction path of the cladding light. The cladding light will enter the outer cladding of the triple-clad bare fiber 2 or be scattered out, thereby realizing the stripping of the cladding light. By fusing the double-clad optical fiber 11 and the triple-clad bare fiber 2 to form a 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-clad optical fiber 11 and the triple-clad bare fiber 2.

[0059] See also Figure 4 , Figure 4 FIG. 1 is a flow chart of a method for manufacturing a cladding light stripper 100 according to a second embodiment of the present invention. In one embodiment, manufacturing a double-clad optical fiber 11 having two sections of double-clad bare fibers 111 extending out of a coating layer 112 includes the following steps:

[0060] S11, taking a section of double-clad optical fiber assembly 1;

[0061] A longer section of double-clad optical fiber 11 is selected, which is equivalent to the double-clad optical fiber assembly 1, and then a mark is made on the middle portion of the double-clad optical fiber.

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

[0063] The operator uses a fiber stripper to carefully strip off the coating 112 in the middle portion of the double-clad optical fiber 11 according to the above-mentioned marked position, exposing the inner double-clad bare fiber 111 in the middle portion 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 , cutting the double-clad bare fiber 111 with a fiber cleaver to form two sections of double-clad optical fiber 11 .

[0065] After cleaning, the operator uses a fiber optic cutting knife to cut the exposed double-clad bare fiber 111, and then performs a flatness treatment on the cut cross section.

[0066] In this embodiment, a longer section of double-clad optical fiber 11 is selected, which is equivalent to the double-clad optical fiber assembly 1, and then the middle part of the double-clad optical fiber 11 is marked. The operator uses a fiber stripper to carefully strip the coating 112 of the middle part of the double-clad optical fiber 11 according to the position of the above mark, exposing the inner double-clad bare fiber 111 in 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 uses a fiber optic cutting knife to cut the exposed double-clad bare fiber 111, and then performs flatness processing on the cut cross-section. Generally speaking, after cutting, the lengths of the two sections of double-clad optical fiber 11 are consistent, and the extended lengths of the double-clad bare fibers 111 are consistent, so that the subsequent production of the cladding light stripper 100 is more beautiful.

[0067] See also Figure 5 , Figure 5 FIG. 3 is a flow chart of a method for manufacturing a cladding light stripper 100 according to a third embodiment of the present invention. In one embodiment, manufacturing the main body 3 includes the following steps:

[0068] S21, taking three sections of triple-clad optical fiber, completely stripping the coating layer 112 of each section of the triple-clad optical fiber to form three sections of triple-clad bare fiber 2, and cleaning the triple-clad bare fiber 2;

[0069] Three sections of three-clad optical fiber with different outer diameters of the inner cladding 22 are selected. The lengths of the three sections of three-clad optical fiber can be equal or unequal. Then, the coating layer 112 of the three sections of three-clad optical fiber is completely stripped off to expose all the three-clad bare fibers 2 in the three-clad optical fiber, and then the three-clad bare fibers 2 are cleaned.

[0070] S22, using a fiber cleaver to cut both sides of each section of triple-clad bare fiber 2;

[0071] After the coating layer 112 is completely stripped off, the operator uses an optical fiber cutter to cut both sides of each section of the three-clad bare fiber 2 so that both sides of each section of the three-clad bare fiber 2 are neat, which is convenient for subsequent fusion splicing.

[0072] S23 , welding the three sections of triple-clad bare optical fibers 2 together using an optical fiber welding machine to form a main body 3 .

[0073] The operator arranges the three sections of triple-clad bare optical fiber 2 in order from large to small according to the size of the outer diameter of the inner cladding 22, and then fuses them in sequence through a fiber fusion splicer to form a main body 3.

[0074] In this embodiment, the three sections of three-clad optical fiber are fused in sequence to achieve multi-level light stripping. Each section of the three-clad optical fiber can further remove the cladding light, thereby improving the cladding light stripping efficiency. By optimizing the parameters of each section of the three-clad optical fiber step by step, a more refined light stripping effect can be achieved, ensuring that the purity of the final output optical signal is very high. The design of the three sections of three-clad optical fiber can better disperse heat and prevent local overheating, thereby improving the thermal stability of the system. Effective thermal management helps to extend the service life of optical fiber devices and improve the reliability and long-term stability of the system. The three sections of three-clad bare fiber 2 are fused in sequence from large to small according to the outer diameter of the inner cladding 22 to form a gradient structure. The outer diameter of the inner cladding 22 of the first section three-cladding 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 section three-cladding bare fiber 2 is second largest. 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 section three-cladding 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 easier to be removed or scattered. The structural arrangement 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] An example is given based on the manufacturing method of the cladding light stripper 100:

[0076] The first step is to take a section of double-clad optical fiber component 1, peel off the middle coating layer 112 of the double-clad optical fiber component 1, and the coating layer 112 peeling length is 3 cm. Then, the double-clad bare fiber 111 is partially cleaned, and the middle double-clad bare fiber 111 area is cut with a fiber optic cutter, and the double-clad optical fiber component 1 is divided into two to form two sections of double-clad bare fiber 111 extending out of the coating layer 112. The second core 111a in the double-clad bare fiber 111 has a diameter of 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] In the second step, three sections of triple-clad optical fiber are taken, and then the coating layer 112 of the triple-clad optical fiber is completely stripped off to form three sections of triple-clad bare fiber 2. The diameter of the first core 21 of the three sections of triple-clad bare fiber 2 is 50um, the outer diameter of the first outer cladding 23 of the three sections of triple-clad bare fiber 2 is 360um, and the outer diameters of the inner cladding 22 of the three sections of triple-clad bare fiber 2 are 300um, 150um, and 70um, respectively. Then, the three sections of triple-clad bare fiber 2 are cleaned, and the two ends of the three sections of triple-clad bare fiber 2 are cut respectively with a fiber optic cutter to make the two ends of the three sections of triple-clad bare fiber 2 flat, and the core numerical aperture of the three sections of triple-clad bare fiber 2 is 0.22.

[0078] In the third step, the three sections of triple-clad bare optical fibers 2 are arranged in descending order according to the size of the outer diameter of the inner cladding 22 , and are fused together by a fiber fusion splicer to form a main body 3 .

[0079] In the fourth step, the two sections of double-clad optical fiber 11 are respectively clad-fused to the two ends of the main body 3 through the double-clad bare fiber 111. 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 triple-clad bare fiber 2, so that the fusion is more stable. The diameter of the second core 111a of the triple-clad bare fiber 2 is consistent with the diameter of the first core 21 of the triple-clad bare fiber 2, which can ensure that the transmission characteristics of the optical signal in the core remain consistent; the core numerical aperture of the double-clad bare fiber 111 is consistent with 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 at the fusion point.

[0080] The fifth step is to make a stripper on the first outer cladding 23 of the main body 3 by laser marking or chemical etching or a combination of the two. In this way, when the cladding light enters the main body 3 during use, the cladding light is gradually stripped out of the first outer cladding 23.

[0081] In summary, using multiple sections of triple-clad bare fiber 2 to make a stripper can prevent a certain section of triple-clad bare fiber 2 from generating local hot spots due to long-term high power, thereby greatly improving the ability of the cladding light stripper 100 to strip cladding light.

[0082] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A cladding light stripper, characterized in that: include: A double-clad optical fiber assembly, the double-clad optical fiber assembly comprising two sections of double-clad optical fibers, each of the double-clad optical fibers comprising a double-clad bare fiber and a coating layer sequentially sheathed from the inside to the outside, the double-clad bare fiber extending out of the coating layer; The triple-clad bare fiber has multiple sections, and the multiple sections of the triple-clad bare fiber are fused in sequence to form a main body. The two sections of the double-clad optical fiber are fused to the two ends of the main body respectively through the double-clad bare fiber, and a stripper is formed on the main body.

2. The cladding light stripper according to claim 1, characterized in that: The triple-clad bare optical fibers are divided into three sections.

3. The cladding light stripper according to claim 2, characterized in that: The three-clad bare fiber includes a first fiber core, an inner cladding and a first outer cladding which are sequentially sleeved from the inside to the outside. The outer diameter of the inner cladding of each of the three-clad bare fibers is different. The three sections of the three-clad bare fiber are sequentially welded according to the outer diameter of the inner cladding from large to small.

4. The cladding light stripper according to claim 3, characterized in that: The double-clad bare fiber comprises a second fiber core and a second outer cladding which are sequentially sleeved from the inside to the outside, and the diameters of the first fiber core and the second fiber core are equal.

5. The cladding light stripper according to claim 4, characterized in that: The outer diameter of the first outer cladding is equal to the outer diameter of the second outer cladding.

6. The cladding light stripper according to claim 4, characterized in that: The core numerical aperture of the double-clad bare fiber is equal to the core numerical aperture of the triple-clad bare fiber.

7. A fiber laser, characterized in that: The fiber laser comprises the cladding light stripper according to any one of claims 1 to 6.

8. A method for manufacturing a cladding light stripper, the method for manufacturing a cladding light stripper being applied to the cladding light stripper as claimed in any one of claims 1 to 6, characterized in that: The manufacturing method of the cladding light stripper comprises the following steps: Making two sections of the double-clad optical fiber with the double-clad bare fiber extending out of the coating layer; Using the triple-clad bare fiber to make the main body; The double-clad bare fibers of the two sections of the double-clad optical fiber are respectively fused to the two ends of the main body; A stripper is made on the main body.

9. The method for manufacturing a cladding light stripper according to claim 8, characterized in that: The manufacturing of the double-clad optical fiber with two sections of double-clad bare fibers extending out of the coating layer comprises the following steps: Take a section of the double-clad optical fiber assembly; Stripping the coating layer of the middle portion of the double-clad optical fiber assembly to expose the double-clad bare fiber, and cleaning the double-clad bare fiber; The double-clad bare fiber is cut by a fiber cleaver to form two sections of the double-clad optical fiber.

10. The method for manufacturing a cladding light stripper according to claim 8, characterized in that: The manufacturing of the main body comprises the following steps: Take three sections of triple-clad optical fiber, completely strip the coating layer of each section of the triple-clad optical fiber to form three sections of triple-clad bare fiber, and clean the triple-clad bare fiber; Use a fiber cleaver to cut both sides of each section of the triple-clad bare fiber; Three sections of triple-clad bare optical fibers are fused together using an optical fiber fusion splicer to form the main body.

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