Testing device for extinction ratio of active polarization maintaining optical fiber

Abstract

The utility model discloses a device for testing the extinction ratio of an active polarization maintaining optical fiber, and relates to the technical field of optical fiber testing. The device comprises a testing device body, a testing optical fiber and a bare fiber protection mechanism, the testing device body comprises an incoherent light source, an adjustable polarizer, a polarization-maintaining mode field adapter, a cladding light stripper and an extinction ratio tester, a bare fiber section is formed on the testing optical fiber by stripping a coating layer, and the bare fiber protection mechanism comprises a protection sleeve and two fastening end sleeves. According to the utility model, through the design of the bare fiber protection mechanism, the bare fiber section on the test optical fiber can be wrapped and protected, the bare fiber section can be efficiently protected, the test optical fiber is prevented from being protected in the process of transferring or installing the test optical fiber on the cladding light stripper, and the service life of the test optical fiber is prolonged. The problem of damage or deformation or surface pollution of the bare fiber section caused by collision or external tension is avoided, and the quality of the bare fiber section of the tested optical fiber before testing is ensured, so that the subsequent testing precision and testing stability are ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of optical fiber testing, in particular to a testing device for the extinction ratio of an active polarization-maintaining optical fiber. Background Art

[0002] Active optical fiber has excellent conversion efficiency, low heat load, high output power and quantum efficiency, making it a key component of high-energy, high-power fiber lasers. However, due to the physical limitations of active optical fibers such as severe nonlinear effects, optical damage, and mode instability, it is difficult for fiber laser systems to achieve high peak power laser output.

[0003] Polarization-maintaining fiber can keep the polarization state of light unchanged, so that the light is transmitted in the fiber as linearly polarized light. Based on the integration of the performance and advantages of active fiber and polarization-maintaining fiber, the technical means of using full polarization-maintaining active fiber to combine coherent light and achieve higher-power laser output is one of the current mainstream solutions.

[0004] Polarization-maintaining fiber is a type of single-mode fiber. Sufficient stress is added to both sides of the single-mode fiber core to produce a large difference in propagation constants in two mutually perpendicular directions on the cross section of the fiber, that is, high birefringence. The extinction ratio is the main indicator to measure the polarization characteristics of polarization-maintaining fiber. The basic method of its test is to convert the measurement of the extinction ratio into the measurement of light intensity through a certain polarization device. Compared with the simple structure, small size and single-mode transmission of polarization-maintaining fiber, the active optical fiber core package has a diverse structure, large size and complex transmission mode. The existing polarization-maintaining fiber extinction ratio test system cannot accurately and stably test the extinction ratio of active polarization-maintaining fiber.

[0005] For the test of optical fiber extinction ratio, it is necessary to strip the coating layer on the optical fiber to form a bare fiber segment. In subsequent tests, the bare fiber segment is immersed in the matching liquid of the cladding light stripper. However, the bare fiber segment has no protection after forming. When the test optical fiber is transferred and installed, the bare fiber segment may be damaged, stretched, deformed, or surface contaminated, affecting the subsequent test accuracy and stability. Utility Model Content

[0006] The utility model aims to provide a test device for the extinction ratio of an active polarization-maintaining optical fiber. Through the design of a bare fiber protection mechanism, the bare fiber segment on the test optical fiber can be wrapped and protected, and the bare fiber segment can be efficiently protected to avoid the test optical fiber from playing a protective role during transfer or installation in a cladding light stripper, to avoid damage or deformation of the bare fiber segment caused by bumps or external tension, or surface contamination, to ensure the quality of the bare fiber segment of the test optical fiber before testing, thereby ensuring subsequent test accuracy and test stability.

[0007] In order to solve the above technical problems, the utility model is realized by the following technical solutions:

[0008] The utility model discloses a testing device for the extinction ratio of an active polarization-maintaining optical fiber, comprising a testing device body, a testing optical fiber and a bare fiber protection mechanism. The testing device body comprises an incoherent light source, an adjustable polarizer, a polarization-maintaining mode field adapter, a cladding light stripper and an extinction ratio tester. A bare fiber section is formed by stripping a coating layer on the testing optical fiber.

[0009] The bare fiber protection mechanism comprises a protective sleeve and two fastening end sleeves;

[0010] Cone heads are provided at both ends of the protective sleeve. The protective sleeve is composed of a group of symmetrically arranged half sleeves. A soft protective layer is fixed on the inner wall of the half sleeves. The two half sleeves are matched and sleeved outside the bare fiber segment. The length of the protective sleeve is greater than the length of the bare fiber segment and both ends extend beyond the bare fiber segment.

[0011] One end of the fastening end sleeve is integrally connected with an elastic telescopic member, and the end of the elastic telescopic member is fixed with a cone sleeve that is gap-matched with the cone head;

[0012] The opposite sides of the integral connection between the fastening end sleeve and the elastic telescopic member are provided with slits, the peripheral side of the fastening end sleeve is provided with a double step groove, the large-diameter end of the double step groove is away from the cone sleeve and is threadedly connected with a fastening nut, two silicone pads are fixed to the inner wall of the fastening end sleeve, and the two slits are respectively located at the connection between the two sides of the two silicone pads;

[0013] An L-shaped support is fixed to the side surface of the fastening end sleeve, and the L-shaped support is located between the two slits;

[0014] The cladding light stripper comprises a liquid mold filled with a matching liquid. Fastening seats are fixed on both sides of the opening of the liquid mold. The L-shaped supports of the fastening end sleeves at both ends of the test optical fiber are fixed to the liquid mold through fasteners and the fastening seats.

[0015] Furthermore, the elastic telescopic part includes an outer cylinder and an inner rod, the outer cylinder and the fastening end sleeve are integrally formed, the inner rod is slidably connected to the outer cylinder, the cone sleeve is fixed to one end of the inner rod away from the outer cylinder, and the other end of the inner rod is located in the outer cylinder and a spring is provided between the inner rod and the outer cylinder.

[0016] Furthermore, the inner rod member located inside the outer cylinder body is fixed with a limit end, and a clearance gap is formed between the peripheral side surface of the limit end and the inner wall of the outer cylinder body.

[0017] Furthermore, the slit is arranged on the outer cylinder and the fastening end sleeve, and the width of the slit increases in sequence from one end of the outer cylinder to the fastening end sleeve.

[0018] Furthermore, an axial hole is provided at the axial center of the inner rod, and the inner diameter of the spring and the aperture of the axial hole are both larger than the outer diameter of the test optical fiber.

[0019] Furthermore, the incoherent light source is an ASE light source that can output stable power, the incoherent light source is connected to an adjustable polarizer through a jumper, the polarization-maintaining mode field adapter input end is connected to the adjustable polarizer output end, the polarization-maintaining mode field adapter output end is connected to the test fiber input end, and the test fiber output end is connected to the extinction ratio tester input end.

[0020] Furthermore, the adjustable polarizer is a mechanically adjustable polarizer, and a polarizing plate and a five-dimensional fine-tuning module are provided inside the adjustable polarizer.

[0021] Furthermore, the bare fiber segment of the test optical fiber is immersed in the matching liquid of the liquid mold, the bare fiber segment is bent in the matching liquid, the length of the bare fiber segment is set in the range of 10-150mm, and the bending radius of the bare fiber segment is set in the range of 10-100mm.

[0022] The utility model provides a method for testing the extinction ratio of an active polarization-maintaining optical fiber, comprising the following steps:

[0023] SS01 takes out the test optical fiber, cuts and processes both ends of the optical fiber and installs the matching connector. Puts on and fixes two fastening end sleeves on one end of the test optical fiber, strips off a certain length of the coating layer of the test optical fiber between the two fastening end sleeves, thereby forming a bare fiber segment. Install a protective sleeve between the two fastening end sleeves to ensure that the bare fiber segment is in the soft protective layer of the two half sleeves.

[0024] SS02 moves the test optical fiber to the position of the cladding light stripper, removes the protective cover of the bare fiber protection mechanism and retains the two fastening end covers, fixes the fastening end covers on the liquid mold through fasteners, L-shaped supports and fastening seats, and exposes the bare fiber section to the outside. The bare fiber section is immersed in the matching liquid of the liquid mold with a certain bending radius through the bending tooling;

[0025] SS03 connects the incoherent light source, adjustable polarizer, polarization-maintaining mode field adapter, test fiber and extinction ratio tester in sequence;

[0026] SS04 turns on the incoherent light source and extinction ratio tester, and adjusts the wavelength of the equipment to match the working wavelength of the test fiber;

[0027] SS05 adjusts the five-dimensional fine-tuning module of the adjustable polarizer. When the extinction ratio tester tests the maximum optical power and the extinction ratio is stable, the extinction ratio value is recorded. This value is the extinction ratio of the tested optical fiber. Furthermore, the installation of the fastening end sleeve and the protective sleeve in the SS01 includes the following steps:

[0028] SS011 inserts two fastening end sleeves from one end of the test optical fiber, accurately determines the installation position and the distance between the two fastening end sleeves, moves the fastening nut from the small-diameter end of the double-step groove to the large-diameter end and tightens it spirally to tighten the slit position, thereby installing the fastening end sleeve on the outside of the test optical fiber;

[0029] SS012 pushes the two cone sleeves to increase the relative distance between the cone sleeves on the two fastening end sleeves to provide space for the protective sleeve. The two half sleeves are connected to the outside of the bare fiber section of the test optical fiber. After the two half sleeves are connected, the cone sleeve is released and reset by the spring. At this time, the two ends of the protective sleeve are stuck in the cone sleeves of the two fastening end sleeves to fasten the protective sleeve. The cone sleeve is pushed again to detach and remove the protective sleeve.

[0030] The utility model has the following beneficial effects:

[0031] 1. The utility model can wrap and protect the bare fiber section on the test optical fiber through the design of the bare fiber protection mechanism, and can effectively protect the bare fiber section, so as to avoid the test optical fiber from being damaged or deformed or surface contamination caused by bumps or external tension, thereby ensuring the quality of the bare fiber section of the test optical fiber before testing, thereby ensuring the subsequent test accuracy and test stability.

[0032] 2. The utility model is designed with a telescopic fastening end sleeve that is easy to disassemble and assemble the protective sleeve, so that the protective sleeve can be quickly disassembled and assembled. The protective sleeve can be quickly removed before testing the optical fiber, which is convenient for the staff to operate, and there is no need to remove the fastening end sleeve. Combined with the design of the fastening seat on the cladding light stripper, the positioning and installation between the test optical fiber and the cladding light stripper can be quickly achieved, which is convenient for operation.

[0033] 3. The test device of the utility model is mainly composed of an incoherent light source, an adjustable polarizer, a polarization-maintaining mode field adapter, a cladding light stripper and an extinction ratio tester. It is simple to operate and has strong versatility. The incoherent light source, the cladding light stripper and the polarization-maintaining mode field adapter are used to ensure that the input to the extinction ratio tester is high-quality fundamental mode transmission high-polarization light, and the test result is stable and accurate.

[0034] 4. The bare fiber protection mechanism designed in the utility model can not only protect the bare fiber section, but also can strip the coating layer of the next test optical fiber in advance during the testing process of the previous test optical fiber, and directly wrap and protect the bare fiber section after it is formed, so that it can be directly used during the test, avoiding the time occupied by stripping the coating layer, and can realize continuous optical fiber testing, thereby improving the testing efficiency.

[0035] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 It is a schematic diagram of the structure when the protective cover and the fastening end cover of the utility model are installed on the test optical fiber;

[0038] Figure 2 It is a structural cross-sectional view of the connection between the protective sleeve, the fastening end sleeve and the test optical fiber;

[0039] Figure 3 It is a schematic diagram of the structure of the test optical fiber and protective cover;

[0040] Figure 4 It is a structural schematic diagram of the fastening end sleeve;

[0041] Figure 5 This is a schematic diagram of the structure after the test optical fiber is connected to the cladding light stripper;

[0042] Figure 6 This is a connection principle block diagram of the utility model;

[0043] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0044] 1-test optical fiber, 2-incoherent light source, 3-adjustable polarizer, 4-polarization-maintaining mode field adapter, 5-cladding light stripper, 6-extinction ratio tester, 7-protective cover, 8-fastening end cover, 101-bare fiber section, 501-liquid mold, 502-fastening seat, 701-cone head, 702-half sleeve, 703-soft protective layer, 801-elastic telescopic part, 802-cone sleeve, 803-slit, 804-double step groove, 805-fastening nut, 806-silicone pad, 807-L-type support, 808-outer cylinder, 809-inner rod, 810-spring, 811-limit end. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0046] See also Figure 1-6As shown, the utility model is a test device for the extinction ratio of an active polarization-maintaining optical fiber, comprising a test device body, a test optical fiber 1 and a bare fiber protection mechanism, wherein the test device body comprises an incoherent light source 2, an adjustable polarizer 3, a polarization-maintaining mode field adapter 4, a cladding light stripper 5 and an extinction ratio tester 6, a bare fiber section 101 is formed by stripping a coating layer on the test optical fiber 1, the test optical fiber 1 is a 20 / 400 ytterbium-doped active polarization-maintaining optical fiber, and the optical fibers at the input and output ends of the polarization-maintaining mode field adapter 4 are both 20 / 400 polarization-maintaining passive optical fibers;

[0047] The bare fiber protection mechanism comprises a protection sleeve 7 and two fastening end sleeves 8;

[0048] Cone heads 701 are provided at both ends of the protective sleeve 7. The protective sleeve 7 is composed of a group of symmetrically arranged half sleeves 702. A soft protective layer 703 is fixed on the inner wall of the half sleeve 702. The two half sleeves 702 are matched and sleeved on the outside of the bare fiber segment 101. The length of the protective sleeve 7 is greater than the length of the bare fiber segment 101 and both ends extend beyond the bare fiber segment 101.

[0049] One end of the fastening end sleeve 8 is integrally connected with an elastic telescopic member 801, and a cone sleeve 802 which is gap-matched with the cone head 701 is fixed at the end of the elastic telescopic member 801;

[0050] The opposite sides of the integral connection between the fastening end sleeve 8 and the elastic telescopic member 801 are provided with slits 803, and the side surfaces of the fastening end sleeve 8 are provided with double-step grooves 804. The large-diameter end of the double-step grooves 804 is away from the cone sleeve 802 and is threadedly connected with a fastening nut 805. Two silicone pads 806 are fixed to the inner wall of the fastening end sleeve 8, and the two slits 803 are respectively located at the connection between the two sides of the two silicone pads 806.

[0051] An L-shaped support 807 is fixed to the side of the fastening end sleeve 8, and the L-shaped support 807 is located between the two slits 803;

[0052] The cladding light stripper 5 includes a liquid mold 501 filled with a matching liquid. Fastening seats 502 are fixed on both sides of the opening of the liquid mold 501. The L-shaped supports 807 of the fastening end sleeves 8 at both ends of the test optical fiber 1 are fixed to the liquid mold 501 through fasteners and the fastening seats 502.

[0053] Among them Figure 1-2 and Figure 4 As shown, the elastic telescopic member 801 includes an outer cylinder 808 and an inner rod 809. The outer cylinder 808 and the fastening end sleeve 8 are integrally formed. The inner rod 809 is slidably connected to the outer cylinder 808. The conical sleeve 802 is fixed to one end of the inner rod 809 away from the outer cylinder 808. The other end of the inner rod 809 is located in the outer cylinder 808 and a spring 810 is provided between the inner rod 809 and the outer cylinder 808.

[0054] Among them Figure 2As shown, the inner rod 809 located inside the outer cylinder 808 is fixed with a limiting end 811, and a clearance gap is formed between the side surface of the limiting end 811 and the inner wall of the outer cylinder 808.

[0055] Among them Figure 1 and Figure 4 As shown, the slit 803 is arranged on the outer cylinder 808 and the fastening end sleeve 8, and the width of the slit 803 increases in sequence from one end of the outer cylinder 808 to the fastening end sleeve 8.

[0056] Among them Figure 2 As shown, an axial hole is provided at the axial center of the inner rod 809 , and the inner diameter of the spring 810 and the aperture of the axial hole are both larger than the outer diameter of the test optical fiber 1 .

[0057] Among them Figure 6 As shown, the incoherent light source 2 is an ASE light source that can output stable power, the incoherent light source 2 is connected to the adjustable polarizer 3 through a jumper, the input end of the polarization-maintaining mode field adapter 4 is connected to the output end of the adjustable polarizer 3, the output end of the polarization-maintaining mode field adapter 4 is connected to the input end of the test optical fiber 1, and the output end of the test optical fiber 1 is connected to the input end of the extinction ratio tester 6;

[0058] The incoherent light source 2 outputs high-quality incoherent light, which is then outputted via the adjustable polarizer 3 to be highly polarized incoherent light, which is then coupled to the test optical fiber 1 via the polarization-maintaining mode field adapter 4, and then outputted via the cladding light stripper 5 to be transmitted as the fundamental mode to be highly polarized light to be sent to the extinction ratio tester 6. The five-dimensional fine-tuning module of the adjustable polarizer 3 is adjusted to measure the extinction ratio of the test optical fiber at the highest output power via the extinction ratio tester 6.

[0059] The wavelengths of the incoherent light source 2 and the adjustable polarizer 3 match the working wavelength of the test optical fiber 1, and the working wavelength is preferably 800-2000nm;

[0060] The extinction ratio tester 6 includes optical power, polarization angle and extinction ratio test functions. The test wavelength of the extinction ratio tester 6 matches the working wavelength of the test optical fiber 1. The preferred optical power accuracy is 0.01-0.1dBm and the extinction ratio accuracy is 0.01-0.1dB.

[0061] The adjustable polarizer 3 is a mechanically adjustable polarizer, and a polarizing plate and a five-dimensional fine-tuning module are arranged inside the adjustable polarizer 3 .

[0062] Among them Figure 5 As shown, the bare fiber segment 101 of the test optical fiber 1 is immersed in the matching liquid of the liquid mold 501, the bare fiber segment 101 is bent and set in the matching liquid, the length of the bare fiber segment 101 is set in the range of 10-150mm, the bending radius of the bare fiber segment 101 is set in the range of 10-100mm, and the refractive index of the matching liquid is preferably 1.0-2.0.

[0063] The utility model provides a method for testing the extinction ratio of an active polarization-maintaining optical fiber, comprising the following steps:

[0064] SS01 takes out the test optical fiber 1, cuts and processes both ends of the optical fiber and installs the matching connector, covers and fixes two fastening end sleeves 8 on one end of the test optical fiber 1, strips a certain length of the coating layer of the test optical fiber 1 between the two fastening end sleeves 8, thereby forming a bare fiber segment 101, and installs a protective sleeve 7 between the two fastening end sleeves 8 to ensure that the bare fiber segment 101 is in the soft protective layer 703 of the two half sleeves 702, wherein the bare fiber segment 101 is about 200-300mm away from the output end of the test optical fiber 1;

[0065] SS02 moves the test optical fiber 1 to the position of the cladding light stripper 5, removes the protective cover 7 of the bare fiber protection mechanism and retains the two fastening end covers 8, fixes the fastening end covers 8 on the liquid mold 501 through the fasteners, the L-shaped support 807 and the fastening seat 502, and at this time the bare fiber segment 101 is exposed to the outside, and the bare fiber segment 101 is immersed in the matching liquid of the liquid mold 501 with a certain bending radius through the bending tool;

[0066] SS03 sequentially connects the incoherent light source 2, the adjustable polarizer 3, the polarization-maintaining mode field adapter 4, the test optical fiber 1 and the extinction ratio tester 6;

[0067] SS04 turns on the incoherent light source 2 and the extinction ratio tester 6, and adjusts the wavelength of the equipment to match the working wavelength of the test optical fiber 1;

[0068] SS05 adjusts the five-dimensional fine-tuning module of the adjustable polarizer 3. When the extinction ratio tester 6 tests the maximum optical power and the extinction ratio is stable, the extinction ratio value is recorded. This value is the extinction ratio of the tested optical fiber 1.

[0069] The installation of the fastening end sleeve 8 and the protective sleeve 7 in SS01 includes the following steps:

[0070] SS011 inserts two fastening end sleeves 8 from one end of the test optical fiber 1, and after accurately determining the installation position and the distance between the two fastening end sleeves 8, moves the fastening nut 805 from the small-diameter end of the double-step groove 804 to the large-diameter end and screws it tight, which can tighten the position of the slit 803, thereby installing the fastening end sleeve 8 on the outside of the test optical fiber 1;

[0071] SS012 pushes the two cone sleeves 802 to increase the relative distance between the cone sleeves 802 on the two fastening end sleeves 8, providing space for the protective sleeve 7, and connects the two half sleeves 702 to the outside of the bare fiber section 101 of the test optical fiber 1. After the two half sleeves 702 are connected, the cone sleeve 802 is released and reset by the spring 810. At this time, the two ends of the protective sleeve 7 are stuck in the cone sleeves 802 of the two fastening end sleeves 8 to fasten the protective sleeve 7. The cone sleeve 802 is pushed again to detach and remove the protective sleeve 7.

[0072] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0073] The preferred embodiments of the utility model disclosed above are only used to help explain the utility model. The preferred embodiments do not describe all the details in detail, nor do they limit the utility model to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the utility model, so that technicians in the relevant technical field can well understand and use the utility model. The utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A test device for the extinction ratio of an active polarization-maintaining optical fiber, comprising a test device body and a test optical fiber (1), wherein the test device body comprises an incoherent light source (2), an adjustable polarizer (3), a polarization-maintaining mode field adapter (4), a cladding light stripper (5) and an extinction ratio tester (6), wherein a bare fiber section (101) is formed by stripping a coating layer on the test optical fiber (1), and wherein: It also includes a bare fiber protection mechanism; The bare fiber protection mechanism comprises a protection sleeve (7) and two fastening end sleeves (8); Both ends of the protective sleeve (7) are provided with a cone head (701), the protective sleeve (7) is composed of a group of symmetrically arranged half sleeves (702), the inner wall of the half sleeves (702) is fixed with a soft protective layer (703), the two half sleeves (702) are matched and sleeved on the outside of the bare fiber section (101), the length of the protective sleeve (7) is greater than the length of the bare fiber section (101) and both ends extend beyond the bare fiber section (101); One end of the fastening end sleeve (8) is integrally connected with an elastic telescopic member (801), and the end of the elastic telescopic member (801) is fixed with a cone sleeve (802) which is clearance-matched with the cone head (701); The opposite sides of the integral connection between the fastening end sleeve (8) and the elastic telescopic member (801) are provided with slits (803); the peripheral side of the fastening end sleeve (8) is provided with a double-step groove (804); the large-diameter end of the double-step groove (804) is away from the cone sleeve (802) and is threadedly connected with a fastening nut (805); two silicone pads (806) are fixed to the inner wall of the fastening end sleeve (8); and the two slits (803) are respectively located at the connection between the two sides of the two silicone pads (806); An L-shaped support (807) is fixed on the side surface of the fastening end sleeve (8), and the L-shaped support (807) is located between the two slits (803); The cladding light stripper (5) comprises a liquid mold (501), the liquid mold (501) is filled with a matching liquid, fastening seats (502) are fixed on both sides of the opening of the liquid mold (501), and L-shaped supports (807) of the fastening end sleeves (8) at both ends of the test optical fiber (1) are fixed to the liquid mold (501) via fasteners and the fastening seats (502).

2. The device for testing the extinction ratio of an active polarization-maintaining optical fiber according to claim 1, characterized in that: The elastic telescopic member (801) comprises an outer cylinder (808) and an inner rod (809); the outer cylinder (808) and the fastening end sleeve (8) are integrally formed; the inner rod (809) is slidably connected to the outer cylinder (808); the cone sleeve (802) is fixed to one end of the inner rod (809) away from the outer cylinder (808); the other end of the inner rod (809) is located inside the outer cylinder (808) and a spring (810) is provided between the inner rod (809) and the outer cylinder (808).

3. The device for testing the extinction ratio of an active polarization-maintaining optical fiber according to claim 2, characterized in that: The inner rod (809) located inside the outer cylinder (808) is fixed with a limit end (811), and a clearance gap is formed between the peripheral side surface of the limit end (811) and the inner wall of the outer cylinder (808).

4. The device for testing the extinction ratio of an active polarization-maintaining optical fiber according to claim 2, characterized in that: The slit (803) is arranged on the outer cylinder (808) and the fastening end sleeve (8), and the width of the slit (803) increases in sequence from one end of the outer cylinder (808) to the fastening end sleeve (8).

5. The device for testing the extinction ratio of an active polarization-maintaining optical fiber according to claim 2, characterized in that: An axial hole is provided at the axial center of the inner rod (809), and the inner diameter of the spring (810) and the diameter of the axial hole are both larger than the outer diameter of the test optical fiber (1).

6. The device for testing the extinction ratio of an active polarization-maintaining optical fiber according to claim 1, characterized in that: The incoherent light source (2) is an ASE light source capable of outputting stable power. The incoherent light source (2) is connected to an adjustable polarizer (3) via a jumper. The input end of the polarization-maintaining mode field adapter (4) is connected to the output end of the adjustable polarizer (3). The output end of the polarization-maintaining mode field adapter (4) is connected to the input end of a test optical fiber (1). The output end of the test optical fiber (1) is connected to the input end of an extinction ratio tester (6).

7. The device for testing the extinction ratio of an active polarization-maintaining optical fiber according to claim 1, characterized in that: The adjustable polarizer (3) is a mechanically adjustable polarizer, and a polarizing plate and a five-dimensional fine-tuning module are arranged inside the adjustable polarizer (3).

8. The device for testing the extinction ratio of an active polarization-maintaining optical fiber according to claim 1, characterized in that: The bare fiber segment (101) of the test optical fiber (1) is immersed in the matching liquid of the liquid mold (501), the bare fiber segment (101) is bent and arranged in the matching liquid, the length of the bare fiber segment (101) is set in the range of 10-150 mm, and the bending radius of the bare fiber segment (101) is set in the range of 10-100 mm.

Images