Ytterbium-doped optical fiber coating defect detection and analysis method

Abstract

The present invention provides a method for detecting and analyzing defects in coating of ytterbium-doped optical fiber, including raw material and tool preparation, optical fiber fixed installation, optical fiber rotation detection, and defect recording and analysis steps. Prepare an optical fiber fixing mold with a light-transmitting hole and an introduction hole, and prepare the ytterbium-doped optical fiber to be tested, a microscope, a matching liquid, and a shooting device. Pass one end of the ytterbium-doped optical fiber to be tested through the introduction hole. Then place the optical fiber fixing mold on the stage of the microscope. Add matching liquid to the light-transmitting hole, observe the ytterbium-doped optical fiber through a microscope, and rotate the ytterbium-doped optical fiber during the observation process to observe the core layer, cladding, inner coating and outer coating respectively. Use a shooting device to shoot and record the defects, and analyze the causes. The method for detecting and analyzing defects in coating of ytterbium-doped optical fiber provided by the present invention can locate the specific position of the coating defect in the structure of the ytterbium-doped optical fiber, and its detection work is more comprehensive and has strong adaptability.

Description

Technical Field

[0001] The invention belongs to the technical field of optical fiber defect detection and analysis, and specifically relates to a method for detecting and analyzing defects in ytterbium-doped optical fiber coatings. Background Art

[0002] Fiber lasers have been widely used in industrial manufacturing, medical treatment, military defense and other fields. Fiber lasers are developing towards higher power, and industrial equipment equipped with high-power fiber lasers ranging from kilowatts to tens of kilowatts will become the mainstream equipment in the high-end manufacturing industry. As the core component of fiber lasers, ytterbium-doped fiber can output high-power lasers, with an output power of up to 10,000 watts. As the laser output power increases, the requirements for coating quality are significantly improved. Since ytterbium-doped optical fibers usually use low-refractive index coatings to achieve a double-cladding structure, compared with general optical fibers, the inner coating of ytterbium-doped optical fibers also transmits light. However, if there are defects inside the ytterbium-doped optical fiber, it is very easy to cause the ytterbium-doped optical fiber to leak light from the defective position and fuse during laser operation. Therefore, the detection and analysis of ytterbium-doped optical fiber coating defects is the first step to solve the coating defect problem.

[0003] In the prior art, for the detection and analysis of ytterbium-doped optical fibers, ordinary optical fiber detection methods are usually used, that is, the detection signal light is coupled into the optical fiber to be tested, and the leaked optical signal is detected in conjunction with the optical detection probe and the optical power meter. In this process, the two ends of the optical fiber are respectively wound on a rewinder or a winding machine, and the optical fiber is transmitted with the synchronous rotation of the two rewinders to achieve defect detection. However, the detection of ytterbium-doped optical fibers involves the positions of the core layer, cladding, inner coating and outer coating, and the above-mentioned detection method can only judge the coating defects, and cannot determine the specific defect location of the coating. Therefore, this transmission method is not applicable. In addition, when using the matching liquid, the matching liquid will leak seriously when the optical fiber transmission method is adopted, which is not easy to clean during the detection process and is seriously wasted. Summary of the invention

[0004] The embodiment of the present invention provides a method for detecting and analyzing defects in ytterbium-doped optical fiber coatings, aiming to solve the problem that the existing optical fiber coating detection method is not applicable to the detection of ytterbium-doped optical fibers.

[0005] To achieve the above object, the technical solution adopted by the present invention is to provide a method for detecting and analyzing defects in ytterbium-doped optical fiber coatings, comprising the following steps:

[0006] Prepare raw materials and tools, prepare an optical fiber fixing mold with a light-transmitting hole and an introduction hole, make the light-transmitting hole and the introduction hole perpendicular to each other and interconnected, and set a light-transmitting plate at one end of the light-transmitting hole; at the same time, prepare the ytterbium-doped optical fiber to be tested, a microscope, a matching liquid, and a photographing device;

[0007] The optical fiber is fixedly installed, and one end of the ytterbium-doped optical fiber to be tested is passed through the introduction hole and sealed and connected with the introduction hole; then the optical fiber fixing mold is placed on the stage of the microscope, and the end with the light-transmitting plate is made to correspond to the light-transmitting area under the stage of the microscope;

[0008] Optical fiber rotation detection, adding the matching liquid into the light-transmitting hole, observing the ytterbium-doped optical fiber through a microscope after the matching liquid is stable, and rotating the ytterbium-doped optical fiber during the observation process to observe the core layer, cladding, inner coating and outer coating respectively;

[0009] Defect recording and analysis: the defects are photographed and recorded by the photographing equipment, and the causes are analyzed.

[0010] In a possible implementation, the ytterbium-doped optical fiber coating defect detection and analysis method further includes a tool surface cleaning step, and after the raw material and tool preparation steps, the surface of the light-transmitting plate and the surface of the microscope stage are cleaned.

[0011] In a possible implementation, a dust blowing gun is used in the tool surface cleaning step.

[0012] In a possible implementation, the optical fiber fixing mold includes:

[0013] The fixed tube has a tube cavity, which is the light-transmitting hole; one end of the light-transmitting hole is provided with a groove for the light-transmitting plate to be embedded; a through hole is provided on the side wall of the fixed tube, which is perpendicular to the tube cavity and communicated with the tube cavity, and the through hole forms two sub-holes on the side wall of the fixed tube;

[0014] There are two rotating cylinders, the two rotating cylinders are rotatably arranged in the two divided holes respectively, one end of each rotating cylinder extends out of the fixed cylinder, and a first nut portion is provided at the extended end of the rotating cylinder; a first opening is provided at one end of each rotating cylinder close to the cylinder cavity, and a second opening is provided at one end where the first nut portion is located, the aperture of the second opening is larger than the aperture of the first opening, and an inner annular surface is formed between the second opening and the first opening;

[0015] There are two locking members, and the two locking members correspond to the two rotating cylinders one by one respectively; each locking member is threadedly connected to the internal thread set in the corresponding second opening, and a through hole is provided on the locking member; the locking member has an outer annular surface adapted to the corresponding inner annular surface; and a second nut portion is provided at one end of each locking member extending out of the second opening;

[0016] There are two sealing rubber rings, which are respectively arranged at the two inner annular surfaces; each sealing rubber ring, each rotating cylinder, each locking member and the through hole are combined to form the introduction hole; the sealing rubber ring is used to extend inward after the locking member rotates relative to the rotating cylinder and is squeezed by the inner annular surface, so as to seal and abut against the outer wall of the ytterbium-doped optical fiber.

[0017] In a possible implementation, the optical fiber fixing mold also includes a limiting clamp, which has a circular hole for the rotating cylinder to pass through, and the limiting clamp has two claws corresponding to the two first nut parts respectively, and each of the claws is provided with a slot for the first nut to enter and limit.

[0018] In a possible implementation, a sealed bearing is provided between the rotating cylinder and the through hole.

[0019] In a possible implementation, an annular seat is fixedly provided at the end of the fixing tube close to the light-transmitting plate, and an annular groove surrounding the fixing tube is provided at one end of the annular seat away from the light-transmitting plate.

[0020] In a possible implementation, the annular seat and the rotating cylinder are spaced apart from each other along the axial direction of the fixed cylinder.

[0021] In a possible implementation, the sealing rubber ring is made of silicone rubber.

[0022] In a possible implementation manner, the light-transmitting plate is a glass plate.

[0023] In this implementation, an optical fiber fixing mold with a light-transmitting hole and an introduction hole is provided, which can form a seal with the ytterbium-doped optical fiber after the ytterbium-doped optical fiber passes through the introduction hole to prevent leakage of the matching liquid. The accuracy of observation is ensured by cleaning the light-transmitting plate and the microscope stage. In addition, by rotating the ytterbium-doped optical fiber, the positions of the core layer, cladding, inner coating and outer coating can be observed separately, and the specific position of the coating defect in the ytterbium-doped optical fiber structure can be located, and its detection work is more comprehensive and adaptable. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A flow chart of a method for detecting and analyzing coating defects of ytterbium-doped optical fiber provided in an embodiment of the present invention;

[0025] Figure 2 Schematic diagram of the optical fiber fixed mold structure used in the ytterbium-doped optical fiber coating defect detection and analysis method provided in the embodiment of the present invention Figure 1 ;

[0026] Figure 3Schematic diagram of the optical fiber fixed mold structure used in the ytterbium-doped optical fiber coating defect detection and analysis method provided in the embodiment of the present invention Figure 2 (Limiting card is detached);

[0027] Figure 4 A schematic diagram of the observation process of the ytterbium-doped optical fiber coating defect detection and analysis method provided in an embodiment of the present invention (the optical fiber fixed mold is a cross-sectional view);

[0028] Figure 5 for Figure 3 Schematic diagram of the limit clamp structure used in the embodiment.

[0029] Description of reference numerals:

[0030] 10. Optical fiber fixing mold; 11. Light transmission hole; 12. Lead-in hole; 13. Fixing cylinder; 131. Annular seat; 132. Annular groove; 14. Rotating cylinder; 15. Locking member; 16. Sealing rubber ring; 17. First nut portion; 18. Second nut portion; 19. Position limiting clamp; 191. Annular ring; 192. Position limiting clamp plate; 193. Bayonet;

[0031] 20. Microscope;

[0032] 30. Matching fluid;

[0033] 40. Handheld optical power meter;

[0034] 50. Translucent board;

[0035] 60. Ytterbium-doped optical fiber. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0037] Please also read Figure 1 and Figure 4 , the ytterbium-doped optical fiber coating defect detection and analysis method provided by the present invention is now described.

[0038] The current detection method can only determine coating defects, but cannot locate the specific position of the coating defects in the structure of the ytterbium-doped optical fiber 60, and cannot play a role in analysis and positioning.

[0039] Therefore, the ytterbium-doped optical fiber coating defect detection and analysis method provided by the embodiment of the present invention comprises the following steps:

[0040] S100: Prepare raw materials and tools, prepare an optical fiber fixing mold 10 with a light-transmitting hole 11 and an introduction hole 12, make the light-transmitting hole 11 and the introduction hole 12 perpendicular to each other and connected to each other, and set a light-transmitting plate 50 at one end of the light-transmitting hole 11. At the same time, prepare the ytterbium-doped optical fiber 60 to be tested, a microscope 20, a matching liquid 30, and a shooting device.

[0041] S300 Fiber fixed installation, one end of the ytterbium-doped fiber 60 to be tested is passed through the introduction hole 12 and sealed with the introduction hole 12. Then the fiber fixing mold 10 is placed on the stage of the microscope 20, and the end with the light-transmitting plate 50 corresponds to the light-transmitting area under the stage of the microscope 20.

[0042] S400 optical fiber rotation detection, adding matching liquid 30 into the light transmission hole 11, observing the ytterbium-doped optical fiber 60 through the microscope 20 after the matching liquid 30 is stable, and rotating the ytterbium-doped optical fiber 60 during the observation process to observe the core layer, cladding, inner coating and outer coating respectively.

[0043] S500 defect recording and analysis: use camera to record defects and analyze the causes.

[0044] Compared with the prior art, the ytterbium-doped optical fiber coating defect detection and analysis method provided in this embodiment is provided with an optical fiber fixing mold 10 having a light-transmitting hole 11 and an introduction hole 12, which can form a seal with the ytterbium-doped optical fiber 60 after the ytterbium-doped optical fiber 60 passes through the introduction hole 12 to prevent leakage of the matching liquid 30. By rotating the ytterbium-doped optical fiber 60, the positions of the core layer, cladding, inner coating and outer coating can be observed separately, and the specific position of the coating defect in the structure of the ytterbium-doped optical fiber 60 can be located, and the detection work is more comprehensive and has strong adaptability.

[0045] For ease of understanding, after the optical fiber fixture 10 is placed on the stage of the microscope 20, its light-transmitting hole 11 is vertically arranged, and the introduction hole 12 is horizontally arranged. At this time, due to the blocking effect of the light-transmitting plate 50, the light-transmitting hole 11 is only open at the top, and the matching liquid 30 can be added thereto, and it is necessary to ensure that the matching liquid 30 does not pass through the ytterbium-doped optical fiber 60 passing through the introduction hole 12. In addition, the matching liquid 30 needs to include a refractive index adaptation with the ytterbium-doped optical fiber 60 to be tested.

[0046] In the optical fiber fixing installation step and the optical fiber rotation detection step, after the optical fiber fixing mold 10 is placed on the stage of the microscope 20 , the transmitted light below the stage is vertically emitted upward into the light transmission hole 11 through the light transmission plate 50 .

[0047] During the detection process, it is necessary to connect a handheld optical power meter 40 to the tail end of the optical fiber and pass red light of 650±10nm band, which is a prior art. At the same time, the position of the light leakage point or impurity point is found in the microscope 20. In addition, the debugging method of the microscope 20 is also a prior art and will not be repeated here.

[0048] It is also necessary to explain that in the defect recording and analysis steps, after locating the defect position, the process personnel will analyze the cause of the problem area. For example, if the impurity point appears in the core layer, it is mainly for the core rod preparation process; if it appears in the cladding, it is necessary to confirm whether there are abnormalities in the pickling, rod sleeve, assembly and other processes; if it appears in the inner and outer coatings, it is mainly for the analysis of the coating system corresponding to the wire drawing process.

[0049] In some embodiments, see Figure 1 The above-mentioned ytterbium-doped optical fiber coating defect detection and analysis method further includes step S200 of cleaning the tool surface. After the raw material and tool preparation steps, the surface of the light-transmitting plate 50 and the surface of the stage of the microscope 20 are cleaned. By cleaning the light-transmitting plate 50 and the stage of the microscope 20, the accuracy of observation is ensured.

[0050] In some embodiments, the tool surface cleaning step may be performed as follows: Figure 1 See the structure shown. Figure 2 In the tool surface cleaning step, a dust blowing gun is used. The dust removal gun can flush the light-transmitting plate 50 and the stage of the microscope 20 by ejecting high-pressure gas, thereby ensuring that the dust is cleaned and the detection effect can be guaranteed.

[0051] In some embodiments, the optical fiber fixing mold 10 can be used as follows: Figures 2 to 4 See the structure shown. Figures 2 to 4The optical fiber fixing mold 10 includes a fixing cylinder 13, a rotating cylinder 14, a locking member 15 and a sealing rubber ring 16. The fixing cylinder 13 has a cylinder cavity, which is a light-transmitting hole 11. One end of the light-transmitting hole 11 is provided with a groove for the light-transmitting plate 50 to be embedded. A through hole perpendicular to the cylinder cavity and connected to the cylinder cavity is provided on the side wall of the fixing cylinder 13, and the through hole forms two sub-holes on the side wall of the fixing cylinder 13. There are two rotating cylinders 14, and the two rotating cylinders 14 are respectively rotatably arranged in the two sub-holes. One end of each rotating cylinder 14 extends out of the fixing cylinder 13, and a first nut portion 17 is provided at the extended end of the rotating cylinder 14. A first opening is provided at one end of each rotating cylinder 14 close to the cylinder cavity, and a second opening is provided at one end where the first nut portion 17 is located. The aperture of the second opening is larger than the aperture of the first opening, and an inner annular surface is formed between the second opening and the first opening. There are two locking members 15, and the two locking members 15 correspond to the two rotating cylinders 14 one by one. Each locking member 15 is threadedly connected to the internal thread set in the corresponding second opening, and a through hole is provided on the locking member 15. The locking member 15 has an outer annular surface adapted to the corresponding inner annular surface. A second nut portion 18 is provided at one end of each locking member 15 extending out of the second opening. Two sealing rubber rings 16 are provided, and the two sealing rubber rings 16 are respectively arranged at the two inner annular surfaces. Each sealing rubber ring 16, each rotating cylinder 14, each locking member 15 and the through hole are combined to form the introduction hole 12. The sealing rubber ring 16 can extend inward after the locking member 15 rotates relative to the rotating cylinder 14 and is squeezed by the inner annular surface, so as to seal and abut against the outer wall of the ytterbium-doped optical fiber 60.

[0052] The principle of using the optical fiber fixing mold 10 is that after cleaning the surface of the light-transmitting plate 50, the two rotating cylinders 14 are fixed by the two first nut parts 17, and then the two locking members 15 are rotated by the second nut part 18 on the locking member 15, so that the two locking members 15 move out of the second opening, and at this time, the pressure of the sealing rubber ring 16 is released and retracted to the area between the inner annular surface and the outer annular surface. The ytterbium-doped optical fiber 60 to be tested passes through the two locking members 15 in turn, and the ytterbium-doped optical fiber 60 is also located in the light-transmitting hole 11, and the two rotating cylinders 14 are still fixed by the two first nut parts 17, and the two locking members 15 are rotated by the second nut part 18, so that the locking member 15 moves inside the second opening, and then the sealing rubber ring 16 is deformed by the extrusion of the outer annular surface and the inner annular surface, and extends to the inside of the introduction hole 12, and the sealing rubber ring 16 abuts against the outer wall of the ytterbium-doped optical fiber 60 to form a seal.

[0053] During the detection process, the fixed cylinder 13 is placed on the stage of the microscope 20, and the light-transmitting plate 50 corresponds to the light-transmitting area of ​​the stage. During the detection process, the rotation of the ytterbium-doped optical fiber 60 is achieved by synchronously rotating the two rotating cylinders 14.

[0054] The sealing contact between the sealing rubber ring 16 and the ytterbium-doped optical fiber 60 can effectively prevent the leakage of the matching liquid 30, thereby avoiding the waste of the matching liquid 30 and preventing the matching liquid 30 from contaminating the stage of the microscope 20. Moreover, this structure can ensure that the ytterbium-doped optical fiber 60 is driven by the rotating cylinder 14 to rotate synchronously, further ensuring the sealing effect between the sealing rubber ring 16 and the ytterbium-doped optical fiber 60 during the rotation process. In addition, the sealing rubber ring 16 has good flexibility and can have a large extension amount, which can ensure that it can adapt to ytterbium-doped optical fibers 60 of different specifications, thereby further enhancing the adaptability.

[0055] In this embodiment, regarding the rotation process of the ytterbium-doped optical fiber 60, the handheld optical power meter 40 connected to the tail end thereof can rotate synchronously, and the specific operation can be assisted by other staff members.

[0056] In addition, if it involves the transfer of the ytterbium-doped optical fiber 60 in the introduction hole 12, the ytterbium-doped optical fiber 60 can be gently pulled because the contact force between the sealing rubber ring 16 and the optical fiber is not very large, and lateral transfer can also be achieved.

[0057] In some embodiments, the above-mentioned limit clamp 19 can be used as follows Figure 5 See the structure shown. Figure 5 The optical fiber fixing mold 10 also includes a limiting clamp 19, which has a round hole for the rotating cylinder 14 to pass through, and the limiting clamp 19 has two claws corresponding to the two first nut parts 17 respectively, and each claw is provided with a bayonet 193 for the first nut to enter and limit.

[0058] The setting of the limiting clamp 19 can ensure that the two first nut parts 17 are limited in position during the installation of the ytterbium-doped optical fiber 60 to prevent the two rotating cylinders 14 from rotating. The limiting clamp 19 can ensure the annular ring 191 and the limiting clamp plate 192 arranged on the outer edge of the annular ring 191 and perpendicular to the annular ring 191. The limiting clamp plate 192 is a claw, and the bayonet 193 is located on the limiting clamp plate 192. Figure 5 The first nut portion 17 may be hexagonal, having three sets of parallel planes, and the width of the bayonet 193 is the same as the distance between the two parallel planes, so as to ensure the simultaneous positioning of the two first nut portions 17 .

[0059] In some embodiments, the rotating drum 14 may be used as follows: Figure 4 See the structure shown. Figure 4 A sealed bearing is provided between the rotating cylinder 14 and the through hole, and the sealed bearing can ensure the rotation connection between the rotating cylinder 14 and the through hole, and at the same time ensure the sealing effect between the two.

[0060] The sub-holes can be stepped holes, for example Figure 4 .

[0061] In some embodiments, the fixing tube 13 may be Figure 4 See the structure shown. Figure 4 The end of the fixing tube 13 close to the light-transmitting plate 50 is fixed with an annular seat 131, and the end of the annular seat 131 away from the light-transmitting plate 50 is provided with an annular groove 132 surrounding the fixing tube 13. When the ytterbium-doped optical fiber 60 passes through the introduction hole 12 horizontally, or the matching liquid 30 overflows due to excessive addition by hand, a small amount of matching liquid 30 may flow out of the light-transmitting hole 11. At this time, the matching liquid 30 can be received by the annular groove 132 to prevent the matching liquid 30 from flowing onto the stage of the microscope 20, thereby ensuring cleanliness and detection effect.

[0062] In some embodiments, the annular seat 131 may be formed as follows: Figures 2 to 4 See the structure shown. Figures 2 to 4 The annular seat 131 and the rotating cylinder 14 are spaced apart along the axial direction of the fixed cylinder 13 . This structure can avoid interference between the annular seat 131 and the rotating cylinder 14 or the locking member 15 .

[0063] In some embodiments, the sealing rubber ring 16 can be made of Figure 4 See the structure shown. Figure 4 The sealing rubber ring 16 is made of silicone rubber, which has good flexibility and good wear resistance, thereby ensuring the sealing effect.

[0064] In some embodiments, the light-transmitting plate 50 may be Figure 4 See the structure shown. Figure 4 The light-transmitting plate 50 is a glass plate, which can be easily cut and installed to ensure the light-transmitting effect.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting and analyzing defects in ytterbium-doped optical fiber coatings, characterized in that: The steps include: Raw materials and tools are prepared, and an optical fiber fixing mold having a light-transmitting hole and an introduction hole is prepared, so that the light-transmitting hole and the introduction hole are arranged perpendicular to each other and connected to each other, and a light-transmitting plate is arranged at one end of the light-transmitting hole; At the same time, prepare the ytterbium-doped optical fiber to be tested, microscope, matching fluid, and photography equipment; The optical fiber is fixedly installed, and one end of the ytterbium-doped optical fiber to be tested is passed through the introduction hole and sealed and connected with the introduction hole; then the optical fiber fixing mold is placed on the stage of the microscope, and the end with the light-transmitting plate is made to correspond to the light-transmitting area under the stage of the microscope; Optical fiber rotation detection, adding the matching liquid into the light-transmitting hole, observing the ytterbium-doped optical fiber through a microscope after the matching liquid is stable, and rotating the ytterbium-doped optical fiber during the observation process to observe the core layer, cladding, inner coating and outer coating respectively; Defect recording and analysis: using the camera to record defects and analyze the causes; Among them, the optical fiber fixing mold used includes a fixed cylinder, a rotating cylinder, a locking piece and a sealing rubber ring; the fixed cylinder has a cylinder cavity, and the cylinder cavity is the light-transmitting hole; one end of the light-transmitting hole is provided with a groove for the light-transmitting plate to be embedded; the side wall of the fixed cylinder is provided with a through hole that is perpendicular to the cylinder cavity and connected to the cylinder cavity, and the through hole forms two sub-holes on the side wall of the fixed cylinder; the rotating cylinder is provided with two, and the two rotating cylinders are respectively rotatably arranged in the two sub-holes, one end of each rotating cylinder protrudes from the fixed cylinder, and a first nut part is provided at the protruding end of the rotating cylinder; each rotating cylinder is provided with a first opening at one end close to the cylinder cavity, and a second opening is provided at the end where the first nut part is located, the aperture of the second opening is larger than the aperture of the first opening, and at the second opening An inner annular surface is formed between the first opening; there are two locking pieces, and the two locking pieces correspond to the two rotating cylinders one by one respectively; each locking piece is threadedly connected to the internal thread set in the corresponding second opening, and a through hole is provided on the locking piece; the locking piece has an outer annular surface adapted to the corresponding inner annular surface; one end of each locking piece extending out of the second opening is provided with a second nut portion; there are two sealing rubber rings, and the two sealing rubber rings are respectively arranged at the two inner annular surfaces; each sealing rubber ring, each rotating cylinder, each locking piece and the through hole are combined to form the introduction hole; the sealing rubber ring is used to extend inwardly after the locking piece rotates relative to the rotating cylinder and is squeezed by the inner annular surface, so as to seal and abut against the outer wall of the ytterbium-doped optical fiber.

2. The method for detecting and analyzing defects in ytterbium-doped optical fiber coating according to claim 1, wherein: The ytterbium-doped optical fiber coating defect detection and analysis method further comprises a tool surface cleaning step, wherein the tool surface cleaning step is performed after the raw material and tool preparation step to clean the surface of the light-transmitting plate and the surface of the microscope stage.

3. The ytterbium-doped optical fiber coating defect detection and analysis method according to claim 2, characterized in that: A dust blowing gun is used in the tool surface cleaning step.

4. The method for detecting and analyzing defects in ytterbium-doped optical fiber coating according to claim 1, wherein: The optical fiber fixing mold also includes a limiting clamp, which has a round hole for the rotating cylinder to pass through, and the limiting clamp has two claws corresponding to the two first nut parts respectively, and each of the claws is provided with a bayonet for the first nut to enter and limit.

5. The ytterbium-doped optical fiber coating defect detection and analysis method according to claim 1, characterized in that: A sealed bearing is provided between the rotating cylinder and the through hole.

6. The ytterbium-doped optical fiber coating defect detection and analysis method according to claim 1, characterized in that: An annular seat is fixedly arranged at the end of the fixing tube close to the light-transmitting plate, and an annular groove surrounding the fixing tube is arranged at one end of the annular seat away from the light-transmitting plate.

7. The method for detecting and analyzing defects in ytterbium-doped optical fiber coating according to claim 6, wherein: The annular seat and the rotating cylinder are spaced apart from each other along the axial direction of the fixed cylinder.

8. The method for detecting and analyzing defects in ytterbium-doped optical fiber coating according to claim 1, wherein: The sealing rubber ring is made of silicone rubber.

9. The method for detecting and analyzing defects in ytterbium-doped optical fiber coating according to claim 1, wherein: The light-transmitting plate is a glass plate.

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