Optical fiber beam combiner capable of resisting high-power return light and manufacturing method

Abstract

The invention provides a high-power return light resistant optical fiber beam combiner and a manufacturing method, the high-power return light resistant optical fiber beam combiner comprises a packaging box, a plurality of input optical fibers and an output optical fiber, the input optical fibers are provided with first filtering parts, the output ends of the input optical fibers are tapered to form taper areas, the output optical fiber is provided with second filtering parts, and the taper areas are welded with the output optical fiber. The first filtering part, the conical area and the second filtering part are arranged in the packaging box, the part, outside the packaging box, of the input optical fiber is provided with a third filtering part, and the part, outside the packaging box, of the output optical fiber is provided with a fourth filtering part. According to the scheme, cladding light is filtered out through two filtering parts outside the beam combiner packaging box, filtering treatment is carried out in the packaging box, the filtering parts form a filtering area, and when entering an input optical fiber cladding from an output optical fiber core, return light leaks out of the filtering area, so that stripping openings of optical fibers at the inlet end and the outlet end are protected, and the service life of the optical fibers at the inlet end and the outlet end is prolonged. And the return light bearing capability of the device is improved.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber combiners, and in particular to an optical fiber combiner resistant to high-power return light and a manufacturing method thereof. Background Art

[0002] Fiber lasers are widely used in industrial manufacturing, aerospace industry, and communication systems because of their good beam quality and high electro-optical conversion efficiency. In practical applications, the laser is reflected by metal parts, causing the laser to return to the laser system. As the laser power increases year by year, the laser power returning to the laser system also gradually increases. As an important component of the laser system, the laser beam combiner is an important factor that limits its higher power application due to the amount of return light it can withstand.

[0003] Fiber lasers need to be used in conjunction with fiber combiners. There are currently two main methods for filtering out cladding light.

[0004] The first method is to filter the combiner, which only welds the cladding light filter before the input fiber and after the output fiber. The disadvantage of this method is that there is no protection for the stripping inside the combiner, and there is no protection for the forward light and the return light. In addition, the cladding light generated at the welding point is not filtered, which affects the internal temperature of the device.

[0005] The second method is to perform filtering in the middle of the input fiber and the output fiber without filtering inside the combiner. The disadvantage is that the input stripping port inside the combiner does not protect the return light, and the output stripping port does not protect the forward light. Summary of the invention

[0006] The first object of the present invention is to provide a fiber combiner that protects the stripped ends of optical fibers and resists high-power return light.

[0007] The second object of the present invention is to provide a method for manufacturing the above-mentioned optical fiber combiner.

[0008] In order to achieve the first purpose of the present invention, the present invention provides a fiber combiner resistant to high-power return light, comprising a packaging box, multiple input optical fibers and an output optical fiber; the output ends of the multiple input optical fibers are provided with a first filtering portion after the coating is stripped, the output ends of the multiple input optical fibers are tapered to form a tapered area, the input end of the output optical fiber is provided with a second filtering portion after the coating is stripped, and the cut tapered area is fused with the input end of the output optical fiber; the first filtering portion, the tapered area and the second filtering portion are arranged in the packaging box, the portion of the input optical fiber outside the packaging box is provided with a third filtering portion after the coating is stripped, and the portion of the output optical fiber outside the packaging box is provided with a fourth filtering portion after the coating is stripped.

[0009] A further solution is that the optical fiber combiner further comprises a glass tube, the output ends of the plurality of input optical fibers penetrate into the glass tube and are then tapered to form a cone region, and the first filtering portion is located in the glass tube.

[0010] A further solution is that a first distance between the first filtering portion and the cutting end surface of the cone region is greater than or equal to 5 mm.

[0011] A further solution is that a second distance between the second filtering portion and the cutting end surface of the cone region is greater than or equal to 5 mm.

[0012] A further solution is that a third distance between the third filtering portion and the cutting end surface of the cone region is greater than or equal to 20 cm.

[0013] A further solution is that a fourth distance between the fourth filtering portion and the cut end surface of the cone region is greater than or equal to 20 cm.

[0014] A further solution is that the etching depth of the first filter portion, the second filter portion, the third filter portion and / or the fourth filter portion is one-stage, two-stage shallow-deep or three-stage shallow-deep-shallow.

[0015] A further solution is that the length ratio of the shallow groove length to the deep groove length in the shallow-deep two-stage type is 1:1 A further solution is that the length ratio of the first shallow groove length, the deep groove length and the second shallow groove length in the shallow-deep-shallow three-stage type is 1:1:1.

[0016] In order to achieve the second objective of the present invention, the present invention provides a method for manufacturing an optical fiber combiner applied to the above-mentioned solution, the manufacturing method comprising: The output ends of the plurality of input optical fibers are provided with a first filtering portion after the coating layers are stripped off; Tapering the output ends of the plurality of input optical fibers to form a tapered region, and cutting the tapered region at the tapered waist to form an end face of the tapered region; The input end of the output optical fiber is provided with a second filtering portion after the coating layer is stripped off; Fusion splicing the end face of the tapered region to the input end of the output optical fiber; The first filter removal portion, the cone area, and the second filter removal portion are arranged in the packaging box; A third filter is provided on the portion of the plurality of input optical fibers outside the packaging box after the coating is stripped off, and a fourth filter is provided on the portion of the output optical fibers outside the packaging box after the coating is stripped off.

[0017] The beneficial effect of the present invention is that, in addition to filtering the cladding light by the third filtering part and the fourth filtering part outside the beam combiner packaging box, the present invention also performs filtering processing inside the beam combiner packaging box, that is, the output end and the input end are filtered by the first filtering part and the second filtering part. The above-mentioned filtering parts form a filtering area. When the return light enters the input optical fiber cladding from the output optical fiber core, it will leak out in the filtering area, thereby protecting the stripping of the optical fiber at the input and output ends and improving the return light tolerance of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the input optical fiber in the embodiment of the optical fiber combiner of the present invention.

[0019] Figure 2 It is a schematic structural diagram of an optical fiber combiner embodiment of the present invention at the taper position.

[0020] Figure 3 It is a schematic diagram of the structure of the optical fiber combiner embodiment of the present invention after fusion splicing.

[0021] Figure 4 It is a schematic diagram of the structure of the optical fiber combiner embodiment of the present invention after packaging.

[0022] The present invention is further described below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0023] Reference Figure 1 When manufacturing the optical fiber combiner of this case, the manufacturing method includes the following steps: the input optical fiber 1 is provided with a coating layer 13, a cladding 12 and a core 11 from the outside to the inside, firstly, the coating layer with a length of 5 cm is removed from the output end of multiple input optical fibers 1, and then a filtering treatment with a length of 2 cm is performed starting from a distance of more than 5 mm from the stripping end. The treatment method includes chemical corrosion, roughening and laser etching, and then the first filtering part 14 is formed.

[0024] Reference Figure 2 The output optical fiber 3 is provided with a coating layer 33, a cladding 32 and a core 31 in sequence from the outside to the inside. Then, the output ends of the multiple input optical fibers 1 are inserted into the glass tube 2 and tapered to form a tapered area 15. The tapered area 15 is cut at the waist to form a tapered area end face 16. The first filtering portion 14 is located in the glass tube 2. The first distance between the first filtering portion 14 and the cut end face 16 of the tapered area 15 is greater than or equal to 5 mm.

[0025] Reference Figure 3Subsequently, after the coating layer is stripped off, the input end 35 of the output optical fiber 3 is provided with a second filter portion 34, and the cone region end face 16 is fused with the input end of the output optical fiber 3. The second distance between the second filter portion 34 and the cut end face 16 of the cone region 15 is greater than or equal to 5 mm, and the length of the second filter portion 34 is 2 cm. The processing methods of the second filter portion 34 include chemical corrosion, roughening and laser etching.

[0026] Reference Figure 4 Finally, the first filter portion 14, the cone region 15 and the second filter portion 34 are arranged in the packaging box 4, and the third filter portion 17 is arranged on the portion of the multiple input optical fibers 1 outside the packaging box 4 after the coating layer is stripped, and the third distance between the third filter portion 17 and the cut end face 16 of the cone region 15 is greater than or equal to 20 cm. The fourth filter portion 36 is arranged on the portion of the output optical fiber 3 outside the packaging box 4 after the coating layer is stripped, and the fourth distance between the fourth filter portion 36 and the cut end face 16 of the cone region 15 is greater than or equal to 20 cm. The processing methods of the third filter portion 17 and the fourth filter portion 36 include chemical corrosion, roughening and laser etching.

[0027] The etching depths of the first filter portion 14, the second filter portion 34, the third filter portion 17 and the fourth filter portion 36 can be adjusted according to actual product requirements. The above-mentioned filter portions can be one-stage, shallow-deep two-stage or shallow-deep-shallow three-stage, wherein the length ratio of the shallow groove length to the deep groove length in the shallow-deep two-stage is 1:1, and the length ratio of the first shallow groove length, the deep groove length and the second shallow groove length in the shallow-deep-shallow three-stage is 1:1:1.

[0028] Through the arrangement of the third filtering section 17 and the fourth filtering section 36, the filtering function is to filter out the cladding light in the returning light, thereby reducing the temperature of the device packaging box, and the arrangement of the first filtering section 14 and the second filtering section 34, the filtering function is to filter out the cladding light that is converted from the core light in the returning light entering the input optical fiber, thereby protecting the stripped end of the optical fiber at the device input end from being burned.

[0029] Of course, the above embodiments are only preferred embodiments of the present case. For example, the beam assembly scheme of the above embodiments adopts the sleeve method, and the present embodiment also includes but is not limited to the twisting method, that is, directly twisting and melting tapers are used on multiple input optical fibers, which can also form a cone area. The melting taper method includes hydrogen-oxygen flame taper, graphite taper, laser taper, and electrode taper. The fiber optic combiner of the present invention is not limited to the production of laser combiners, but is also applicable to the production of pump combiners. As for the arrangement of the number of input optical fibers, it is applicable to the production of all (N+1)X1(N≥3) combiners.

[0030] As can be seen from the above, in addition to filtering the cladding light through the third and fourth filtering parts outside the combiner packaging box, the present invention also performs filtering processing inside the combiner packaging box, that is, the output end and the input end are filtered through the first and second filtering parts. The above filtering parts form a filtering area. When the return light enters the input optical fiber cladding from the output optical fiber core, it will leak out in the filtering area, thereby protecting the stripping of the optical fiber at the input and output ends and improving the return light tolerance of the device.

Claims

1. A fiber combiner resistant to high-power return light, characterized in that: It includes a packaging box, a plurality of input optical fibers and an output optical fiber; The output ends of the plurality of input optical fibers are provided with a first filter portion after the coating layer is stripped off, the output ends of the plurality of input optical fibers are tapered to form a cone region, the input end of the output optical fiber is provided with a second filter portion after the coating layer is stripped off, and the cut cone region is fused with the input end of the output optical fiber; The first filter portion, the cone region and the second filter portion are arranged in the packaging box, the portion of the input optical fiber outside the packaging box is provided with a third filter portion after the coating layer is stripped off, and the portion of the output optical fiber outside the packaging box is provided with a fourth filter portion after the coating layer is stripped off.

2. The optical fiber combiner according to claim 1, characterized in that: The optical fiber combiner further comprises a glass tube, and the output ends of the plurality of input optical fibers are inserted into the glass tube and then tapered to form the tapered area, and the first filtering portion is located in the glass tube.

3. The optical fiber combiner according to claim 1, characterized in that: A first distance between the first filtering portion and the cutting end surface of the cone region is greater than or equal to 5 mm.

4. The optical fiber combiner according to claim 1, characterized in that: A second distance between the second filtering portion and the cutting end surface of the cone region is greater than or equal to 5 mm.

5. The optical fiber combiner according to claim 1, characterized in that: A third distance between the third filtering portion and the cutting end surface of the cone region is greater than or equal to 20 cm.

6. The optical fiber combiner according to claim 1, characterized in that: A fourth distance between the fourth filtering portion and the cutting end surface of the cone region is greater than or equal to 20 cm.

7. The optical fiber combiner according to any one of claims 1 to 6, characterized in that: The etching depth of the first filter removal portion, the second filter removal portion, the third filter removal portion and / or the fourth filter removal portion is one-stage, two-stage shallow-deep or three-stage shallow-deep-shallow.

8. The optical fiber combiner according to claim 7, characterized in that: The length ratio of the shallow groove length to the deep groove length in the shallow-deep two-stage method is 1:

1.

9. The optical fiber combiner according to claim 7, characterized in that: The length ratio of the first shallow groove length, the deep groove length and the second shallow groove length in the shallow-deep-shallow three-stage type is 1:1:

1.

10. The method for manufacturing the optical fiber combiner according to any one of claims 1 to 9, characterized in that: The production method comprises: After stripping the coating layer, the output ends of the plurality of input optical fibers are provided with a first filtering portion; Tapering the output ends of the plurality of input optical fibers to form a tapered region, and cutting the tapered waist of the tapered region to form an end face of the tapered region; The input end of the output optical fiber is provided with a second filtering portion after the coating layer is stripped off; Fusion-joining the end face of the tapered region with the input end of the output optical fiber; The first filter removal portion, the cone area and the second filter removal portion are arranged in the packaging box; A third filter is provided at a portion of the plurality of input optical fibers outside the packaging box after the coating is stripped off, and a fourth filter is provided at a portion of the output optical fibers outside the packaging box after the coating is stripped off.

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