Method for manufacturing side-pumped beam combiner and optical fiber fusion splicing method thereof

Abstract

The present invention belongs to the field of optical transmission technology, and discloses a method for fusion splicing optical fibers of different diameters, wherein a first optical fiber and a second optical fiber of different diameters are prepared; one end of a first coating layer is stripped with a first length to expose a first cladding; the exposed first cladding is acid-etched or laser-ablated to make the diameter of the first cladding equal to the diameter of the second cladding; the end of the corroded or ablated first cladding is cut off; one end of a second coating layer is stripped with a second length to expose the second cladding, and the end of the second cladding is cut off; the exposed first cladding and the second cladding are fusion spliced. The present invention can improve the strength of the fusion point while significantly improving the laser passing efficiency in the fiber core.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical transmission, and in particular relates to a method for manufacturing a side-pumped beam combiner and a method for fusing optical fibers thereof. Background Art

[0002] At present, in the technology of optical fiber fusion splicing, there is a problem of different-diameter fusion splicing. Optical fibers fused by existing technology have different-diameter fusion splicing points, which leads to problems such as large insertion loss and low fusion strength that affect the overall performance.

[0003] like Figure 1 As shown, in some prior arts, although a higher laser passing efficiency can be obtained, the strength of the weld point is not high and it is easy to break;

[0004] like Figure 2 As shown, in some other prior arts, although the problem of weld point strength is solved and fracture is avoided, the laser passing efficiency is lost, so the use effect of the formed product is poor. Summary of the invention

[0005] In order to solve the above technical problems, the present invention discloses a method for welding optical fibers of different diameters, which can improve the strength of the welding point and significantly improve the laser passing efficiency in the fiber core. The specific technical solution of the present invention is as follows:

[0006] Prepare a first optical fiber and a second optical fiber, wherein the first optical fiber includes a first cladding and a first coating layer coated outside the first cladding, and the second optical fiber includes a second cladding and a second coating layer coated outside the second cladding, and the diameter of the first cladding is greater than the diameter of the second cladding;

[0007] Stripping one end of the first coating layer by a first length to expose the first cladding layer;

[0008] Acid-etching or laser-ablating the exposed first cladding so that the diameter of the first cladding is equal to the diameter of the second cladding;

[0009] Cutting off the end of the first cladding after corrosion or ablation;

[0010] Stripping one end of the second coating layer with a second length to expose the second cladding layer, and cutting off the end of the second cladding layer;

[0011] The exposed first cladding layer and the second cladding layer are fused together.

[0012] Preferably, the first length is 30 mm to 70 mm.

[0013] Preferably, the first cladding layer is vertically extended into the acid solution for corrosion, and the liquid surface of the acid solution is 10 to 55 mm away from the stripping position of the first coating layer.

[0014] Preferably, the end of the etched first cladding is cut at an angle of 0° to 1°.

[0015] Preferably, the second length is 30 mm to 65 mm.

[0016] Preferably, the exposed end of the second cladding is cut at an angle of 0° to 1°.

[0017] Preferably, when the first cladding and the second cladding are welded, the angle formed by the straight line where the center line of the first cladding is located and the straight line where the center line of the second cladding is located is 0° to 0.5°.

[0018] Preferably, the exposed first cladding is corroded by acid solution, wherein the acid solution is hydrofluoric acid with a concentration of 20% to 40% and the corrosion temperature is 25°C to 28°C.

[0019] Preferably, it also includes:

[0020] Encapsulating the welded first cladding and the second cladding by using a sleeve;

[0021] Before packaging, the first cladding and the second cladding are coated with a roughening agent to form an uneven cladding surface, and then the sleeve is glued and packaged.

[0022] A method for manufacturing a side-pumped beam combiner, comprising:

[0023] preparing a signal optical fiber, wherein the signal optical fiber is manufactured by the above-mentioned fusion splicing method of optical fibers with different diameters;

[0024] Prepare at least one pump fiber;

[0025] Remove the coating of the signal optical fiber to expose its cladding;

[0026] The middle part of the pump fiber is processed into a cone structure, and the side of the cone structure is melted to the cladding of the signal fiber;

[0027] The pump optical fiber is cut off at the waist of the cone structure to form a first cone section and a second cone section at the fusion joint, one end of the first cone section is fused to the cladding and connected to the second cone section, and there is a gap between the second cone section and the cladding;

[0028] The second cone section is attached to the cladding and heated so that the end surface of the second cone section is welded to the cladding to eliminate the gap.

[0029] Compared with the prior art, the present invention processes optical fibers of different diameters into two optical fibers with the same cladding diameter, thereby realizing optical fiber fusion splicing and high-strength cladding connection. On this basis, since the core diameter of the optical fiber is not changed, a good laser transmission efficiency is guaranteed. After detection, the laser transmission efficiency can be increased from 90% to more than 96%, thereby reducing insertion loss. In addition, the present invention ensures the stability of the cladding connection and improves the strength. The present invention also makes the application of the side-pumped combiner more flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of one of the prior arts;

[0031] Figure 2 It is a schematic diagram of another prior art;

[0032] Figure 3 This is a schematic diagram of the structure presented in step S102 of the present invention;

[0033] Figure 4 This is a schematic diagram of the structure presented in step S105 of the present invention;

[0034] Figure 5 This is a schematic diagram of the structure presented in step S106 of the present invention.

[0035] Figure 6 This is a schematic diagram of the structure presented in step S205 of the present invention;

[0036] Figure 7 A schematic diagram of a side-pumped beam combiner according to an embodiment of the present invention;

[0037] Figure 8 FIG. 4 is a schematic diagram of another side-pumped combiner according to an embodiment of the present invention.

[0038] In the figure: 1-first fiber core; 2-first cladding; 3-first coating layer; 4-second fiber core; 5-second cladding; 6-second coating layer; 7-acid solution; 8-casing; 9-signal fiber; 10-pump fiber; 11-first cone; 12-second cone; 13-gap. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0040] like Figure 3 to Figure 5 As shown, a method for fusion splicing optical fibers of different diameters comprises:

[0041] S101, preparing a first optical fiber and a second optical fiber, wherein the first optical fiber comprises a first core 1, a first cladding 2 coated on the outside of the first core 1, and a first coating layer 3 coated on the outside of the first cladding 2, and the second optical fiber comprises a second core 4, a second cladding 5 coated on the outside of the second core 4, and a second coating layer 6 coated on the outside of the second cladding 5, and the diameter of the first cladding 2 is greater than the diameter of the second cladding 5;

[0042] S102, peeling off one end of the first coating layer 3 by a first length to expose the first cladding 2; corroding the exposed first cladding 2 with an acid solution 7 or laser ablation to make the diameter of the first cladding 2 equal to the diameter of the second cladding 5;

[0043] S103, cutting the end of the first cladding 2 after corrosion or ablation;

[0044] S104, stripping off one end of the second coating layer 6 by a second length to expose the second cladding layer 5, and cutting the end of the second cladding layer 5;

[0045] S105 , welding the exposed first cladding 2 and the second cladding 5 .

[0046] In the process of optical fiber processing, it is generally necessary to process the coating layer. However, before two optical fibers are fused, the first cladding 2 and the second cladding 5 have different diameters. If they are directly fused, the following will be obtained: Figure 1 In the fusion structure shown in the figure, due to the different diameters of the cladding, the fusion-spliced ​​optical fiber is easily broken when it is bent during use, and the break position is located at the joint of the first cladding 2 and the second cladding 5. In other processes, in order to ensure that the optical fiber has a certain strength, the cladding and the core are treated to a certain extent. Figure 2 As shown, it has certain strength, but the fiber fusion condition is poor, resulting in a large loss of laser transmission efficiency.

[0047] Therefore, in this embodiment, when performing the diameter reduction process, the diameter of the first cladding 2 is first made equal to the diameter of the second cladding 5, and then the optical fibers are fused and finally packaged. Therefore, the fused optical fiber can not only meet the strength requirements and is not easy to bend and break, but also meet the laser passing efficiency and meet the optical fiber use requirements.

[0048] In order to better use this embodiment, the first length is 30 mm to 70 mm; the first cladding 2 is vertically extended into the acid solution 7 for corrosion, and the liquid surface of the acid solution 7 is 10 to 55 mm away from the stripping position of the first coating layer 3. The second length is 30 mm to 65 mm.

[0049] The fusion of the first fiber core 1 and the second fiber core 4 needs to meet certain prerequisite requirements, so that on the basis of satisfying the core fusion, the correspondence between the claddings can be flat and reliable. If the above length is too small, the operation of the core fusion process is not easy, and if the above length is too large, the accuracy of the cladding docking is poor. In addition, the first cladding 2 and the acid solution 7 should be in the same vertical plane to meet the docking integrity between the first cladding 2 and the second cladding 5.

[0050] In order to better use this embodiment, the end of the etched first cladding layer 2 is cut at an angle of 0° to 1°. The end of the exposed second cladding layer 5 is cut at an angle of 0° to 1°.

[0051] After the end of the first cladding 2 and the end of the second cladding 5 are cut, the length of the first cladding 2 exposed by the first optical fiber is 20 mm to 55 mm, and the length of the second cladding 5 exposed by the second optical fiber is 25 mm to 60 mm. Therefore, the above lengths can well meet the prerequisites for fusion splicing.

[0052] Similarly, on the basis of meeting the process length, the end of the first cladding 2 and the end of the second cladding 5 can be better butted together, and the end faces of the two can have a certain inclination angle, or the cross section can be used as the end face. When the end face has a certain inclination angle, the angle should not be too large, otherwise the length of the cross section will be longer, thus affecting the butt-jointing stability of the cladding end faces.

[0053] In order to better use this embodiment, when the first cladding 2 and the second cladding 5 are welded, the angle formed by the straight line where the center line of the first cladding 2 is located and the straight line where the center line of the second cladding 5 is located is 0° to 0.5°.

[0054] Since the first cladding 2 covers the first fiber core 1 and the second cladding 5 covers the second fiber core 4, it can be understood that the angle formed by the straight line where the center line of the first fiber core 1 is located and the straight line where the center line of the second fiber core 4 is located is 0° to 0.5°.

[0055] In this embodiment, errors are allowed in the fusion of the first fiber core 1 and the second fiber core 4. However, since the angle formed by the straight line where the center line of the first fiber core 1 and the straight line where the center line of the second fiber core 4 is located is 0° to 0.5°, the existence of the above error actually has little effect on the strength of the optical fiber after fusion.

[0056] In order to better use this embodiment, after step S105, the following steps are further included:

[0057] S106 , using the sleeve 8 to encapsulate the butted first cladding 2 and the second cladding 5 .

[0058] Before packaging, the first cladding 2 and the second cladding 5 are coated with a roughening agent to form an uneven cladding surface, and then the sleeve 8 is packaged by glue dot.

[0059] The hairing agent is a corrosive solvent known to those skilled in the art, and can be used directly in this embodiment. The packaging of the sleeve 8 is equivalent to providing a third coating layer for the first cladding 2 and the second cladding 5 that are still exposed after welding, thereby further ensuring the strength of the welded optical fiber, thereby ensuring the stability of use for the different-diameter welding process. Of course, it can also be understood that in other embodiments, in order to ensure better stability, the third coating layer simultaneously covers the first coating layer 3 and the second coating layer 6.

[0060] In order to better use this embodiment, the exposed first cladding 2 is corroded by an acid solution 7, wherein the acid solution 7 is hydrofluoric acid with a concentration of 20% to 40% and a corrosion temperature of 25°C to 28°C.

[0061] The concentration of hydrofluoric acid, the corrosion temperature, and the diameter difference of the cladding all affect the corrosion time. When the diameter of the first cladding 2 is constant, the corrosion efficiency of the first cladding 2 is best when the concentration of hydrofluoric acid is 20% to 40% and the corrosion temperature is 25°C to 28°C.

[0062] The distance between the liquid surface of the acid solution 7 and the stripping position of the first coating layer 3 is set as a first distance. Therefore, the parameters corresponding to each process of this embodiment are as follows.

[0063]

[0064] It should be noted that the above parameters only represent the specific values ​​involved in the specific process of this embodiment. In other embodiments, it is not necessary to perform working operations completely corresponding to the values ​​in the above table, but it is only necessary to ensure that each value is within the data range of the corresponding parameter.

[0065] A method for manufacturing a side-pumped beam combiner, comprising:

[0066] S201 prepares a signal optical fiber 9, wherein the signal optical fiber 9 is manufactured by the fusion splicing method of optical fibers with different diameters as described above;

[0067] S202, preparing at least one pump optical fiber 10;

[0068] S203, removing the coating layer of the signal optical fiber 9 to expose its cladding;

[0069] S204, processing the middle portion of the pump optical fiber 10 into a cone structure, and melting the side of the cone structure to the cladding of the signal optical fiber 9;

[0070] S205, truncating the pump optical fiber 10 at the waist of the cone structure, forming a first cone section 11 and a second cone section 12 at the fusion joint, one end of the first cone section 11 is fusion-joined to the cladding and connected to the second cone section 12, and there is a gap 13 between the second cone section 12 and the cladding;

[0071] S206, heat the second cone segment 12 in contact with the cladding, so that the end surface of the second cone segment 12 is fused to the cladding.

[0072] The pump combiner is the core part of the fiber laser, and its fiber performance can determine the output efficiency and quality of the laser. In some pump combiners, its fiber is made by different diameter fusion splicing. Therefore, in order to ensure the product quality of the pump combiner, its fiber is made by the above-mentioned different diameter fusion splicing method.

[0073] In the manufacturing process of the pump combiner, the pump fiber 10 needs to be fused to the cladding of the signal fiber 9 and its end needs to be completely fitted to the cladding of the signal fiber 9 to avoid heat accumulation. On this basis, it is ensured that the pump combiner has a higher power usage.

[0074] like Figure 6 As shown, in step S205, the end of the first cone segment 11 away from the second cone segment 12 is used to pass the pump light. If the second cone segment 12 is retained, light leakage is likely to occur at the second cone segment 12, thereby generating heat accumulation. Therefore, step S206 is used to eliminate the gap 13 between the second cone segment 12 and the cladding, that is, the end of the second cone segment 12 is bonded to the cladding. In this process, the position of the second cone segment 12 can be measured by a microscope, and then the second cone segment 12 can be positioned and bonded to the surface of the cladding using a fixture. It should be noted that the end face of the second cone segment 12 includes the side face of the end.

[0075] Different from the above-mentioned embodiments, in some other embodiments, the second cone segment 12 can be removed by corrosion, generally speaking, also by hydrofluoric acid. However, in this process, it is necessary to avoid secondary corrosion of the cladding by hydrofluoric acid, and also to avoid corrosion of the first cone segment 11 by hydrofluoric acid. The process difficulty is greater than that of the present embodiment.

[0076] In addition, for different embodiments, there may be one or more pump fibers 10. For example, in this embodiment, the pump combiner is a (2+1)×1 pump combiner, that is, it has two pump fibers 10. Therefore, it can be understood that the number of pump fibers 10 is not limited to one or two, but may also be three, four or more.

[0077] Therefore, after step S201, there are still the following steps:

[0078] S2011, preparing a first optical fiber and a second optical fiber, wherein the first optical fiber comprises a first core 1, a first cladding 2 coated on the outside of the first core 1, and a first coating layer 3 coated on the outside of the first cladding 2, and the second optical fiber comprises a second core 4, a second cladding 5 coated on the outside of the second core 4, and a second coating layer 6 coated on the outside of the second cladding 5, and the diameter of the first cladding 2 is greater than the diameter of the second cladding 5;

[0079] S2012, peeling off one end of the first coating layer 3 by a first length to expose the first cladding 2; corroding the exposed first cladding 2 with an acid solution 7 or laser ablation to make the diameter of the first cladding 2 equal to the diameter of the second cladding 5;

[0080] S2013, cutting the end of the first cladding 2 after corrosion or ablation;

[0081] S2014: stripping one end of the second coating layer 6 by a second length to expose the second cladding layer 5, and cutting the end of the second cladding layer 5;

[0082] S2015, fusing the exposed first cladding 2 and the second cladding 5 to obtain the signal optical fiber 9.

[0083] In addition, it should be noted that Figure 7 and Figure 8 As described above, the pump fiber 10 can be fused to a cladding with a larger diameter or a cladding with a smaller diameter.

[0084] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for fusion splicing optical fibers of different diameters, characterized in that: include: Prepare a first optical fiber and a second optical fiber, wherein the first optical fiber includes a first cladding and a first coating layer coated outside the first cladding, and the second optical fiber includes a second cladding and a second coating layer coated outside the second cladding, and the diameter of the first cladding is greater than the diameter of the second cladding; Stripping one end of the first coating layer by a first length to expose the first cladding layer; Acid-etching or laser-ablating the exposed first cladding so that the diameter of the first cladding is equal to the diameter of the second cladding; Cutting off the end of the first cladding after corrosion or ablation; Stripping one end of the second coating layer with a second length to expose the second cladding layer, and cutting off the end of the second cladding layer; welding the exposed first cladding and the second cladding; Wherein, the first length is 30 mm to 70 mm; The first cladding is vertically extended into the acid solution for etching, wherein the liquid surface of the acid solution is 10 to 55 mm away from the stripping position of the first coating layer; The end of the etched first cladding layer is cut at an angle of 0° to 1°.

2. A method for fusion splicing optical fibers of different diameters as claimed in claim 1, characterized in that: The second length is 30 mm to 65 mm.

3. A method for fusion splicing optical fibers of different diameters as claimed in claim 2, characterized in that: The exposed end of the second cladding is cut at an angle of 0° to 1°.

4. A method for fusion splicing optical fibers of different diameters as claimed in claim 1, characterized in that: When the first cladding and the second cladding are welded, the angle formed by the straight line where the center line of the first cladding is located and the straight line where the center line of the second cladding is located is 0° to 0.5°.

5. A method for fusion splicing optical fibers of different diameters as claimed in any one of claims 1 to 4, characterized in that: The exposed first cladding is corroded by acid solution, wherein the acid solution is hydrofluoric acid with a concentration of 20% to 40% and a corrosion temperature of 25°C to 28°C.

6. A method for fusion splicing optical fibers of different diameters as claimed in claim 1, characterized in that: Also includes: Encapsulating the welded first cladding and the second cladding by using a sleeve; Before packaging, the first cladding and the second cladding are coated with a roughening agent to form an uneven cladding surface, and then the sleeve is glued and packaged.

7. A method for manufacturing a side-pumped beam combiner, characterized in that: include: Prepare a signal optical fiber, the signal optical fiber is made by the fusion splicing method of optical fibers with different diameters as described in any one of claims 1 to 6; Prepare at least one pump fiber; Remove the coating of the signal optical fiber to expose its cladding; The middle part of the pump fiber is processed into a cone structure, and the side of the cone structure is melted to the cladding of the signal fiber; The pump optical fiber is cut at the waist of the cone structure to form a first cone section and a second cone section at the fusion joint, one end of the first cone section is fused to the cladding and connected to the second cone section, and there is a gap between the second cone section and the cladding; The second cone section is attached to the cladding and heated so that the end surface of the second cone section is welded to the cladding to eliminate the gap.

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