Device and method for testing optical transmission performance of passive optical fiber

Abstract

The invention discloses a passive optical fiber optical transmission performance testing device and method, and the device comprises a single-mode single-wavelength light source, an optical fiber patch cord, a red light source, a beam combiner, an extended optical fiber, a tested passive optical fiber, an optical axis calibrator, an attenuation piece, a CCD (Charge Coupled Device) and a processor, the optical axis calibrator, the attenuation slice and the CCD are sequentially arranged at one end, far away from the extended optical fiber, of the passive optical fiber to be tested, the beam combiner is further connected with the red light source, and the CCD is connected with the processor. According to the device and the method for testing the optical transmission performance of the passive optical fiber, the distribution change condition of the light spots after the laser passes through the tested passive optical fiber is evaluated by calculating the ovality of the light spots and the sizes of the long axis and the short axis of the light spots, and the influence of different technological processes on the transmission performance of the passive optical fiber and the optical transmission performance of the passive optical fiber are judged; test time is short, safety is high, and cost is low.

Description

Technical Field

[0001] The invention belongs to the technical field of optical communication, and in particular relates to a passive optical fiber optical transmission performance testing device and method. Background Art

[0002] Fiber lasers have remarkable application prospects in material processing, medical treatment, communication, remote sensing, and national defense security due to their good heat dissipation, compact structure, easy maintenance, and easy high-power single-mode laser output. Passive optical fiber is the basic material for fiber devices such as pump sources, beam combiners, fiber gratings, cladding light filters, and QBH in fiber lasers. The optical transmission performance of passive optical fiber directly affects the beam quality of optical fiber devices and fiber lasers. The optical transmission performance of passive optical fiber is not only related to the geometric dimensions, refractive index distribution, numerical aperture, loss and other parameters of the passive optical fiber, but also to the optical fiber manufacturing process. The slight deviations in the passive optical fiber manufacturing process of different batches are difficult to reflect from the optical fiber parameters such as geometric dimensions, refractive index distribution, numerical aperture, and loss. Therefore, it is necessary to provide a passive optical fiber optical transmission performance test device and method. Summary of the invention

[0003] In order to solve the technical problems existing in the prior art, the object of the present invention is to provide a passive optical fiber optical transmission performance testing device and method.

[0004] In order to achieve the above purpose and the above technical effect, the technical solution adopted by the present invention is:

[0005] A passive optical fiber optical transmission performance test device comprises a single-mode single-wavelength light source, an optical fiber jumper, a red light source, a beam combiner, an extended optical fiber, a passive optical fiber to be tested, an optical axis calibrator, an attenuation plate, a CCD and a processor. One end of the optical fiber jumper is connected to the single-mode single-wavelength light source, and the other end is connected to the beam combiner and then connected to the extended optical fiber and the passive optical fiber to be tested in sequence. The optical axis calibrator, the attenuation plate and the CCD are sequentially arranged at one end of the passive optical fiber to be tested away from the extended optical fiber. The beam combiner is also connected to the red light source. The CCD is connected to the processor. The light output by the single-mode single-wavelength light source passes through the optical fiber jumper, the beam combiner, the extended optical fiber and the passive optical fiber to be tested in sequence, and then is calibrated by the optical axis calibrator, and then enters the CCD through the attenuation plate. Then, the processor calculates the spot ellipticity, the major axis and the minor axis dimensions of the spot to evaluate the spot distribution change after the laser passes through the passive optical fiber to be tested, so as to judge the influence of different process processes on the transmission performance of the passive optical fiber and the optical transmission performance of the passive optical fiber.

[0006] Furthermore, the passive optical fiber optical transmission performance test device also includes a lifting platform, and the output end of the extended optical fiber or the passive optical fiber to be tested is arranged on the lifting platform.

[0007] Furthermore, the single-mode single-wavelength light source is used to provide single-mode single-wavelength light, and its output light spot has uniform light distribution, the spot ellipticity is ≥95%, the wavelength is 1030-1080nm, the power is 1-5mW, and the output port is a FA / APC connector.

[0008] Furthermore, the fiber optic patch cord is a single-mode fiber optic patch cord, the fiber model is Hi1060, one end of the fiber optic patch cord is a FA / APC connector for coupling with a single-mode single-wavelength light source, and the other end is a bare fiber end face for fusion splicing with an input fiber of a combiner.

[0009] Furthermore, the output wavelength of the red light source is 600-700nm.

[0010] Furthermore, the output end face of the tested passive optical fiber is 10-30 mm away from the detection surface of the attenuation plate.

[0011] Furthermore, the optical axis calibrator includes a light inlet sheet, a light inlet sheet hole, a light outlet sheet, a light outlet sheet hole, a base and a foot pad. The light inlet sheet and the light outlet sheet are coaxially arranged at the two ends of the base. The light inlet sheet and the light outlet sheet are respectively provided with a light inlet sheet hole and a light outlet sheet hole at their center positions. A height-adjustable foot pad is arranged under the base.

[0012] Furthermore, the base is a hollow long strip structure with an open top, a long side parallel to the horizontal direction, and a length of ≥20 cm.

[0013] The present invention also discloses a method for testing the optical transmission performance of a passive optical fiber, comprising the following steps:

[0014] 1) During the test, first confirm whether the spot ellipticity of the single-mode single-wavelength light source is ≥95%:

[0015] Couple the single-mode single-wavelength light source with the FA / APC connector of the optical fiber jumper, fuse the bare fiber end face of the optical fiber jumper with one input optical fiber of the combiner, fuse the red light source with another input optical fiber of the combiner, fuse the output end of the combiner with the extended optical fiber, and fix the output end face of the extended optical fiber on the lifting platform;

[0016] The red light source is controlled to emit red light, and the red light is sequentially output through the beam combiner and the extended optical fiber. The position of the lifting platform is adjusted and the optical axis calibrator is used for calibration to ensure that the red light beam output by the extended optical fiber coincides with the central axis of the attenuation plate. After the optical path calibration is completed, the red light source is turned off and the optical axis calibrator is removed. After adjusting the output end face of the extended optical fiber to be 10-30 mm away from the detection surface of the attenuation plate, the single-mode single-wavelength light source is turned on, and the spot image is collected by the CCD and transmitted to the processor. The spot ellipticity of the single-mode single-wavelength light source is calculated by the processor. When it is confirmed that the spot ellipticity of the single-mode single-wavelength light source is ≥95%, step 2) is performed.

[0017] 2) Connect the output end of the extended optical fiber to the passive optical fiber under test, and place the output end of the passive optical fiber under test on a lifting platform;

[0018] The red light source is controlled to emit red light. The red light emitted by the red light source passes through the beam combiner, the extended optical fiber, and the passive optical fiber under test in turn. The position of the lifting platform is adjusted and the optical axis calibrator is used for calibration to ensure that the red light beam output by the passive optical fiber under test coincides with the central axis of the attenuation plate. After the optical path calibration is completed, the red light source is turned off and the optical axis calibrator is removed. After adjusting the output end face of the extended optical fiber to be 10-30mm away from the detection surface of the attenuation plate, the single-mode single-wavelength light source is turned on, and the spot image is collected by the CCD and transmitted to the processor. The spot ellipticity of the single-mode single-wavelength light source is calculated by the processor. When the tested spot ellipticity is ≥95% and the major and minor axis sizes of the spot meet the use requirements, it proves that the passive optical fiber under test has small spot distortion and excellent transmission performance.

[0019] Furthermore, the calculation formula of the spot ellipticity is:

[0020] η=D1 / D2

[0021] Among them, η is the spot ellipticity, which is used to describe the beam quality. The size of the spot ellipticity affects the efficiency and quality of laser processing in laser applications; D1 is the spot size in the direction perpendicular to the optical axis; D2 is the spot size in the direction parallel to the optical axis; the closer D1 and D2 are, the closer η is to 100%, indicating that the spot quality is better, and the spot distortion is smaller after the single-mode single-wavelength light is transmitted through the passive optical fiber;

[0022] The spot size calculation formula is:

[0023] ω'=2λf / πω

[0024] The diameter calculation formula for 86% of the focused laser energy is:

[0025] d0=λf / ω

[0026] Among them, ω' is the spot diameter, ω is the laser beam radius, λ is the incident laser wavelength, f is the focal length of the lens, and d0 is the diameter containing 86% of the focused laser energy.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention discloses a passive optical fiber optical transmission performance testing device and method, which can judge the influence of the passive optical fiber's process other than geometrical dimensions, refractive index distribution, numerical aperture, loss and other parameters on the passive optical fiber transmission performance and evaluate the passive optical fiber transmission performance by the light spot distortion after the laser passes through the passive optical fiber, and has the advantages of short testing time, high safety and low cost, and is a reliable evaluation method for the passive optical fiber optical transmission performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the present invention;

[0030] Figure 2 It is a structural schematic diagram of the optical axis calibrator of the present invention;

[0031] Figure 3 It is a schematic diagram of step 1) of a method for testing the optical transmission performance of a passive optical fiber of the present invention. DETAILED DESCRIPTION

[0032] The present invention is described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0033] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0034] like Figure 1-3As shown, a passive optical fiber optical transmission performance test device comprises a single-mode single-wavelength light source 1, an optical fiber jumper 2, a red light source 3, a beam combiner 4, an extended optical fiber 5, a passive optical fiber to be tested 6, a lifting platform 7, an optical axis calibrator 8, an attenuation plate 9, a CCD 10 and a display 11 connected in sequence, wherein one end of the optical fiber jumper 2 is connected to the single-mode single-wavelength light source 1, and the other end is connected to the beam combiner 4 and then connected to the extended optical fiber 5 and the passive optical fiber to be tested 6 in sequence, the output end of the extended optical fiber 5 or the passive optical fiber to be tested 6 is arranged on the lifting platform 7, the optical axis calibrator 8, the attenuation plate 9 and the CCD 10 are arranged in sequence at the end of the passive optical fiber 6 to be tested away from the extended optical fiber 5, the beam combiner 4 is also connected to the red light source 3, and the CCD 10 is connected to the processor 11. The light output by the single-mode single-wavelength light source 1 passes through the fiber jumper 2, the beam combiner 4, the extended fiber 5 and the passive fiber 6 to be tested in sequence, and then is calibrated by the optical axis calibrator 8, and then enters the CCD 10 through the attenuation plate 9. The processor 11 then calculates the spot ellipticity, the major axis and the minor axis dimensions of the spot to evaluate the change in the spot distribution after the laser passes through the passive fiber 6 to be tested, and to judge the impact of different process steps on the transmission performance of the passive fiber and the optical transmission performance of the passive fiber.

[0035] The single-mode single-wavelength light source 1 is used to provide single-mode single-wavelength light, and its output light spot has uniform light distribution, the spot ellipticity is ≥95%, the wavelength range is 1030-1080nm, the power is 1-5mW, and the output port is FA / APC connector.

[0036] The optical fiber jumper 2 is a single-mode optical fiber jumper, and the optical fiber model is Hi1060. One end of the optical fiber jumper 2 is a FA / APC connector, which is coupled and connected to the single-mode single-wavelength light source 1, and the other end is a bare fiber end face of the optical fiber, which is fused with an input optical fiber of the combiner 4.

[0037] The output wavelength of the red light source 3 is 600-700nm, which is used for naked eye observation. The optical axis coincides with the vertical center axis of the attenuation plate 9 and the CCD 10 to avoid measurement errors caused by the angle of the optical path entering the CCD 10. Because the angle of the output fiber optical axis directly affects the test result of the spot ellipticity, the spot ellipticity can only be accurately measured when the output fiber optical axis completely coincides with the center axis of the CCD 10 mirror. Its advantage is that red light is visible to the naked eye, and the optical path adjustment can be completed without the assistance of night vision goggles.

[0038] The beam combiner 4 is used to ensure that the output light of the single-mode single-wavelength light source 1 and the red light path of the red light source 3 coincide with each other after being output through the beam combiner pigtail.

[0039] The two ends of the extended optical fiber 5 are fused with the output tail fiber of the combiner 4 and the passive optical fiber 6 under test respectively, and its size matches the size of the passive optical fiber 6 under test to ensure that the light entering the passive optical fiber 6 under test is single mode.

[0040] The tested passive optical fiber 6 is a passive optical fiber whose light spot ellipticity needs to be tested.

[0041] The lifting platform 7 can be adjusted in multiple directions such as up and down, left and right, and pitch to ensure that the light beam output from the fixed optical fiber end face coincides with the central axis of the attenuation plate 9 and the CCD 10 mirror, and the distance between the output end face of the tested passive optical fiber 6 and the detection surface of the attenuation plate 9 is 10-30mm.

[0042] The optical axis calibrator 8 includes a light inlet sheet 12, a light inlet sheet hole 13, a light outlet sheet 14, a light outlet sheet hole 15, a base 16 and a foot pad 17. The base 16 is a long rectangular parallelepiped with an open top and a hollow interior. The length of the rectangular parallelepiped is ≥20 cm, and the long side is parallel to the horizontal direction. The light inlet sheet 12 and the light outlet sheet 14 are embedded in the smallest group of faces among the six faces of the base 16, and the planes of the light inlet sheet 12 and the light outlet sheet 14 coincide with the planes of the embedded rectangular parallelepiped. The light inlet sheet 12 and the light outlet sheet 14 each have a small hole at the center of the axis in the vertical plane direction, which are the light inlet sheet hole 13 and the light outlet sheet hole 15 respectively. The line connecting the center points of the small holes of the light inlet sheet 12 and the light outlet sheet 14 is parallel to the horizontal direction. The four corners below the base 16 are equipped with height-adjustable foot pads 17 for adjusting the level of the optical axis calibrator 8.

[0043] The attenuation sheet 9 is used to ensure that the light saturation entering the CCD 10 is 20%-100%, which matches the signal acquisition capability of the CCD.

[0044] CCD 10 is used to collect the light spot image, and its collection wavelength range is 1470nm-1605nm, and is used to calculate the parameters such as the light spot ellipticity, the light spot size, and the length of the light spot along the coordinate axis.

[0045] A method for testing the optical transmission performance of a passive optical fiber, the detection principle is: after a single-mode single-wavelength light beam with uniform light spot distribution and light spot ellipticity ≥ 95% passes through the passive optical fiber 6 under test, if the transmission performance of the passive optical fiber 6 under test is poor, the output light spot will be distorted and the light spot ellipticity will deteriorate; if the transmission performance of the passive optical fiber 6 under test is good, the output light spot will still be uniform and the light spot ellipticity will be ≥ 95%. The method mainly includes the following steps:

[0046] 1) During the test, first confirm whether the spot ellipticity of the single-mode single-wavelength light source 1 is ≥95%:

[0047] The single-mode single-wavelength light source 1 is coupled to the FA / APC connector of the optical fiber jumper 2, the bare fiber end face of the optical fiber jumper 2 is fused to an input optical fiber of the combiner 4, the red light source is fused to another input optical fiber of the combiner, the output end of the combiner is fused to the extended optical fiber, and the output end face of the extended optical fiber 5 is fixed on the lifting platform 7;

[0048] The red light source 3 is controlled to emit red light, and the red light is outputted through the beam combiner 4 and the extended optical fiber 5 in sequence. By adjusting the position of the lifting platform 7 and calibrating with the optical axis calibrator 8, it is ensured that the red light beam outputted by the extended optical fiber 5 coincides with the central axis of the attenuation plate 9; after the optical path calibration is completed, the red light source 3 is turned off and the optical axis calibrator 8 is removed; after adjusting the output end face of the extended optical fiber 5 to be 10-30 mm away from the detection surface of the attenuation plate 9, the single-mode single-wavelength light source 1 is turned on, and the spot image is collected by the CCD 10 and transmitted to the processor 11, and the spot ellipticity of the single-mode single-wavelength light source 1 is calculated by the processor 11. When it is confirmed that the spot ellipticity of the single-mode single-wavelength light source 1 is ≥95%, step 2) is performed;

[0049] 2) Connecting the output end of the extended optical fiber 5 to the passive optical fiber 6 to be tested, and placing the output end of the passive optical fiber 6 to be tested on the lifting platform 7;

[0050] The red light source 3 is controlled to emit red light. The red light emitted by the red light source 3 is outputted through the beam combiner 4, the extended optical fiber 5, and the passive optical fiber 6 under test in sequence. By adjusting the position of the lifting platform 7 and calibrating with the optical axis calibrator 8, it is ensured that the red light beam output by the passive optical fiber 6 under test coincides with the central axis of the attenuation plate 9. After the optical path calibration is completed, the red light source 3 is turned off and the optical axis calibrator 8 is removed. After adjusting the output end face of the extended optical fiber 5 to be 10-30mm away from the detection surface of the attenuation plate 9, the single-mode single-wavelength light source 1 is turned on, and the spot image is collected by the CCD 10 and transmitted to the processor 11. The spot ellipticity of the single-mode single-wavelength light source 1 is calculated by the processor 11. When the tested spot ellipticity is ≥95% and the major and minor axis dimensions of the spot meet the use requirements, it is proved that the passive optical fiber 6 under test has small spot distortion and excellent transmission performance.

[0051] The calculation formula of the spot ellipticity is:

[0052] η=D1 / D2

[0053] Among them, η is the spot ellipticity, which is used to describe the beam quality. The size of the spot ellipticity affects the efficiency and quality of laser processing in laser applications; D1 is the spot size in the direction perpendicular to the optical axis; D2 is the spot size in the direction parallel to the optical axis; the closer D1 and D2 are, the closer η is to 100%, which means the better the spot quality is, and the smaller the spot distortion is after the single-mode single-wavelength light is transmitted through the passive optical fiber.

[0054] The spot size calculation formula is:

[0055] ω'=2λf / πω

[0056] The diameter calculation formula for 86% of the focused laser energy is:

[0057] d0=λf / ω

[0058] Among them, ω' is the spot diameter, ω is the laser beam radius, λ is the incident laser wavelength, f is the focal length of the lens, and d0 is the diameter containing 86% of the focused laser energy.

[0059] Parts or structures not specifically described in the present invention may adopt existing technologies or existing products and will not be described in detail here.

[0060] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A passive optical fiber optical transmission performance test device, characterized in that: The invention comprises a single-mode single-wavelength light source, an optical fiber jumper, a red light source, a beam combiner, an extended optical fiber, a passive optical fiber to be tested, an optical axis calibrator, an attenuation plate, a CCD and a processor. One end of the optical fiber jumper is connected to the single-mode single-wavelength light source, and the other end is connected to the beam combiner, which is then connected to the extended optical fiber and the passive optical fiber to be tested in sequence. The optical axis calibrator, the attenuation plate and the CCD are sequentially arranged at one end of the passive optical fiber to be tested away from the extended optical fiber. The beam combiner is also connected to the red light source, and the CCD is connected to the processor.

2. A passive optical fiber optical transmission performance test device according to claim 1, characterized in that: The passive optical fiber optical transmission performance test device also includes a lifting platform, and the output end of the extended optical fiber or the passive optical fiber to be tested is arranged on the lifting platform.

3. A passive optical fiber optical transmission performance test device according to claim 1, characterized in that: The single-mode single-wavelength light source is used to provide single-mode single-wavelength light, and its output light spot has uniform light distribution, the spot ellipticity is ≥95%, the wavelength is 1030-1080nm, the power is 1-5mW, and the output port is a FA / APC connector.

4. A passive optical fiber optical transmission performance test device according to claim 1, characterized in that: The fiber optic patch cord is a single-mode fiber optic patch cord, the fiber model is Hi1060, one end of the fiber optic patch cord is a FA / APC connector for coupling and connecting with a single-mode single-wavelength light source, and the other end is a bare fiber end face for fusion splicing with an input fiber of a combiner.

5. A passive optical fiber optical transmission performance test device according to claim 1, characterized in that: The output wavelength of the red light source is 600-700nm.

6. A passive optical fiber optical transmission performance test device according to claim 1, characterized in that: The output end face of the tested passive optical fiber is 10-30 mm away from the detection face of the attenuation plate.

7. A passive optical fiber optical transmission performance test device according to claim 1, characterized in that: The optical axis calibrator includes a light inlet sheet, a light inlet sheet hole, a light outlet sheet, a light outlet sheet hole, a base and a foot pad. The light inlet sheet and the light outlet sheet are coaxially arranged at the two ends of the base. The light inlet sheet and the light outlet sheet are respectively provided with a light inlet sheet hole and a light outlet sheet hole at their center positions. A height-adjustable foot pad is arranged under the base.

8. A passive optical fiber optical transmission performance test device according to claim 7, characterized in that: The base is a hollow long strip structure with an open top, a long side parallel to the horizontal direction, and a length of ≥20 cm.

9. A method for testing the optical transmission performance of a passive optical fiber, characterized in that: The following steps are involved: 1) During the test, first confirm whether the spot ellipticity of the single-mode single-wavelength light source is ≥95%: Couple the single-mode single-wavelength light source with the FA / APC connector of the optical fiber jumper, fuse the bare fiber end face of the optical fiber jumper with one input optical fiber of the combiner, fuse the red light source with another input optical fiber of the combiner, fuse the output end of the combiner with the extended optical fiber, and fix the output end face of the extended optical fiber on the lifting platform; The red light source is controlled to emit red light, and the red light is sequentially output through the beam combiner and the extended optical fiber. The position of the lifting platform is adjusted and the optical axis calibrator is used for calibration to ensure that the red light beam output by the extended optical fiber coincides with the central axis of the attenuation plate. After the optical path calibration is completed, the red light source is turned off and the optical axis calibrator is removed. After adjusting the output end face of the extended optical fiber to be 10-30 mm away from the detection surface of the attenuation plate, the single-mode single-wavelength light source is turned on, and the spot image is collected by the CCD and transmitted to the processor. The spot ellipticity of the single-mode single-wavelength light source is calculated by the processor. When it is confirmed that the spot ellipticity of the single-mode single-wavelength light source is ≥95%, step 2) is performed. 2) Connect the output end of the extended optical fiber to the passive optical fiber under test, and place the output end of the passive optical fiber under test on a lifting platform; The red light source is controlled to emit red light. The red light emitted by the red light source passes through the beam combiner, the extended optical fiber, and the passive optical fiber under test in turn. The position of the lifting platform is adjusted and the optical axis calibrator is used for calibration to ensure that the red light beam output by the passive optical fiber under test coincides with the central axis of the attenuation plate. After the optical path calibration is completed, the red light source is turned off and the optical axis calibrator is removed. After adjusting the output end face of the extended optical fiber to be 10-30mm away from the detection surface of the attenuation plate, the single-mode single-wavelength light source is turned on, and the spot image is collected by the CCD and transmitted to the processor. The spot ellipticity of the single-mode single-wavelength light source is calculated by the processor. When the tested spot ellipticity is ≥95% and the major and minor axis sizes of the spot meet the use requirements, it proves that the passive optical fiber under test has small spot distortion and excellent transmission performance.

10. A passive optical fiber optical transmission performance testing method according to claim 9, characterized in that: The calculation formula of the spot ellipticity is: η=D1 / D2 Among them, η is the spot ellipticity, which is used to describe the beam quality. The size of the spot ellipticity affects the efficiency and quality of laser processing in laser applications; D1 is the spot size in the direction perpendicular to the optical axis; D2 is the spot size in the direction parallel to the optical axis; the closer D1 and D2 are, the closer η is to 100%, indicating that the spot quality is better, and the spot distortion is smaller after the single-mode single-wavelength light is transmitted through the passive optical fiber; The spot size calculation formula is: ω'=2λf / πω The diameter calculation formula for 86% of the focused laser energy is: d0=λf / ω Among them, ω' is the spot diameter, ω is the laser beam radius, λ is the incident laser wavelength, f is the focal length of the lens, and d0 is the diameter containing 86% of the focused laser energy.

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