Active optical fiber photon darkening performance test system

Abstract

The utility model provides an active fiber photon darkening performance test system comprising an indication light input optical path used for dividing indication light into a plurality of sub indication light; the pump light input light path is used for dividing the pump light into a plurality of branch pump light; the active optical fiber test light path comprises a plurality of active optical fiber test branches, one branch indication light and one branch pump light are input into the input end of each active optical fiber test branch, and the active optical fiber is tested after beam combination; and the signal monitoring unit comprises an optical power meter which is connected with the output end of each active optical fiber test branch and is used for monitoring the optical power of each active optical fiber test branch. The system comprises a plurality of active optical fiber test branches, can synchronously monitor the darkening performance of multiple paths of active optical fibers in real time, does not need to build a plurality of experimental devices for testing respectively, reduces the waste of equipment resources, and greatly saves the test time.

Description

Technical Field

[0001] The utility model belongs to the technical field of optical fiber lasers, and in particular relates to an active optical fiber photon darkening performance testing system. Background Art

[0002] Photon darkening testing is a key area of research in active optical fiber performance. Currently, the most effective method uses short-wavelength lasers as indicator light to monitor the photodarkening process. However, testing a single fiber typically requires significant time, often requiring several hours for a single test.

[0003] During the actual R&D and production process, the existing test system was completely unable to meet the existing testing requirements due to the large number and variety of optical fibers to be tested. For each fiber of different sizes and models, a complete optical path with matching dimensions must be rebuilt, requiring multiple sets of light sources and components. As a test platform, the goal was to minimize test time, improve test efficiency, and reduce resource waste. This required the design of an efficient and versatile test system that could meet the needs of parallel testing of multiple fiber groups, while also providing supporting software for data collection and improved testing efficiency. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide an active optical fiber photon darkening performance test system, which can be applicable to the synchronous test of darkening performance of multiple active optical fibers and reduce resource waste.

[0005] The technical solutions adopted by the present invention to solve the above technical problems are:

[0006] An active optical fiber photon darkening performance test system, comprising:

[0007] An indicator light input optical path is provided with a signal light beam splitter for splitting the indicator light into a plurality of sub-indicator lights;

[0008] A pump light input optical path, wherein a pump light beam splitter is provided in the pump light input optical path for splitting the pump light into a plurality of sub-pump lights;

[0009] An active optical fiber test optical path includes a plurality of active optical fiber test branches, wherein an input end of each active optical fiber test branch inputs one of the sub-indicator lights and one of the sub-pump lights, and the active optical fiber is tested after being combined;

[0010] The signal monitoring unit includes an optical power meter, which is respectively connected to the output end of each active optical fiber test branch and is used to monitor the optical power of each active optical fiber test branch.

[0011] According to the above solution, each active optical fiber test branch includes a signal pump combiner, an optical mode stripper and an optical fiber filter arranged in sequence; wherein,

[0012] The two input ends of the signal pump combiner are respectively input with one of the sub-indicator lights and one of the sub-pump lights;

[0013] The output end of the signal pump combiner and the input end of the optical stripper are used to connect the active optical fiber under test; the model of the signal pump combiner is adjusted according to the size of the active optical fiber under test, so that the output fiber at the output end of the signal pump combiner matches the size of the active optical fiber under test;

[0014] The optical mode stripper is used to strip away the residual pump light in the optical fiber cladding of the active optical fiber and retain the indicator light in the core;

[0015] Fiber filters are used to further filter the residual pump light in the optical path.

[0016] According to the above solution, the active optical fiber test branch further includes a light-absorbing housing, which is arranged at the output end of the signal pump combiner when there is no active optical fiber to be tested in the active optical fiber test branch during testing.

[0017] According to the above solution, the light transmission range of the optical fiber filter is such that the transmittance of the wavelength band where the indicator light is located is above 95%.

[0018] According to the above solution, the indicator light input optical path includes an indicator light source, a first optical isolator and the signal light beam splitter connected in sequence. The indicator light output by the indicator light source passes through the first optical isolator and then outputs the plurality of split indicator lights by the signal light beam splitter.

[0019] The pump light input optical path includes a pump light source, a second optical isolator and the pump light beam splitter which are optically connected in sequence. The pump light output by the pump light source passes through the second optical isolator and then outputs the plurality of branch pump lights by the pump light beam splitter.

[0020] According to the above solution, the active optical fiber is an erbium-ytterbium co-doped optical fiber; the pump light source is a semiconductor pump laser with a wavelength of 940nm and an adjustable output power of 0~100W.

[0021] According to the above solution, the active optical fiber is an ytterbium-doped optical fiber; the pump light source is a semiconductor pump laser with a wavelength of 915nm or 976nm, and the output power is adjustable from 0 to 100W.

[0022] According to the above solution, the optical power meter is a multi-channel optical power meter, and the output end of each active optical fiber test branch is respectively connected to a channel of the optical power meter.

[0023] According to the above solution, the signal monitoring unit further includes a data processing unit electrically connected to the optical power meter.

[0024] According to the above scheme, the indicator light source is a monochromatic laser light source with a wavelength of 200nm-1100nm.

[0025] The beneficial effects of the utility model are:

[0026] 1. The utility model includes several active optical fiber test branches, which can monitor the darkening performance of multiple active optical fibers in real time and synchronously. There is no need to build multiple experimental devices for separate testing, which reduces the waste of equipment resources and greatly saves testing time.

[0027] 2. Each active optical fiber test branch directly uses a signal pump combiner for cladding pumping, and the signal pump combiner models can be diversified. Different signal pump combiners have different output fiber sizes. The test fiber can select a link with matching size for testing. That is, the fiber mode matching can be achieved by adjusting the signal pump combiner model. It has universality, making the active optical fiber darkening performance test batch-based and greatly improving the speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the principle of an embodiment of the present utility model.

[0029] Figure 2 This is a schematic diagram of another application scenario of an embodiment of the present utility model.

[0030] In the picture:

[0031] 1- indicator light input optical path, 11- indicator light source, 12- first optical isolator, 13- signal light beam splitter;

[0032] 2-pump light input optical path, 21-pump light source, 22-second optical isolator, 23-pump light beam splitter;

[0033] 3-active fiber test optical path, 31-signal pump combiner, 32-optical mode stripper, 33-fiber filter, 34-light absorbing shell;

[0034] 4-Signal monitoring unit, 41-Optical power meter, 42-Data processing unit;

[0035] 5- Active optical fiber. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to 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] In the description of this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this invention, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0038] The utility model provides an active optical fiber photon darkening performance test system, such as Figure 1 As shown, it includes an indicator light input optical path 1, a pump light input optical path 2, an active optical fiber test optical path 3 and a signal monitoring unit 4.

[0039] The indicator light input optical path 1 includes an indicator light source 11, a first optical isolator 12 and a signal light beam splitter 13 which are optically connected in sequence. The indicator light output by the indicator light source 11 passes through the first optical isolator 12 and then outputs a plurality of split indicator lights by the signal light beam splitter 13.

[0040] The pump light input optical path 2 includes a pump light source 21, a second optical isolator 22 and the pump light beam splitter 23 which are sequentially connected. The pump light output by the pump light source 21 passes through the second optical isolator 22 and then outputs a plurality of branch pump lights by the pump light beam splitter 23.

[0041] The active optical fiber test optical path 3 includes several active optical fiber test branches. The input end of each active optical fiber test branch inputs one of the sub-indicator lights and one of the sub-pump lights. After combining, the active optical fiber is tested.

[0042] Specifically, each active optical fiber test branch includes a signal pump combiner 31, an optical mode stripper 32, and an optical fiber filter 33, which are arranged in sequence. The two input ends of the signal pump combiner 31 respectively input one of the sub-indicator light and one of the sub-pump light to combine the two optical paths. The output end of the signal pump combiner 31 and the input end of the optical mode stripper 32 are used to connect the active optical fiber 5 under test; the model of the signal pump combiner 31 is adjusted according to the size of the active optical fiber 5 under test so that the output fiber at the output end of the signal pump combiner 31 matches the size of the active optical fiber 5 under test. The optical mode stripper 32 is used to strip away the residual pump light in the optical fiber cladding of the active optical fiber 5 and retain the indicator light in the core. The optical fiber filter 33 is used to further attenuate the pump light. The active optical fiber test branch of this embodiment can directly use the signal pump combiner 31 for cladding pumping, and optical fiber mode matching can be achieved by adjusting the model of the signal pump combiner 31. When different types of active optical fibers need to be tested simultaneously, it is only necessary to adjust the model of the signal pump combiner 31 of the corresponding active optical fiber test branch.

[0043] The signal monitoring unit 4 includes an optical power meter 41, which is connected to the output end of each active optical fiber test branch and is used to monitor the optical power of each active optical fiber test branch. In this embodiment, the optical power meter 41 is a multi-channel optical power meter, and the output end of each active optical fiber test branch is connected to a channel of the optical power meter 41. To facilitate secondary processing of the measured signals, the signal monitoring unit may also include a data processing unit 42, which is electrically connected to the optical power meter 41. The data processing unit 42 is preferably a computer.

[0044] In this embodiment, the following settings are made for the selection of each component:

[0045] Because additional losses are greater in short-wavelength bands, measurement accuracy can be greatly improved. In this embodiment, a monochromatic laser light source with a short wavelength of 200nm-1100nm can be selected as the indicator light source, such as typical wavelengths of 355nm, 405nm, 633nm, and 793nm. However, it should be noted that excessive indicator light power can cause photobleaching of the photon darkening effect. To reduce the additional photon darkening losses, the indicator light power should be adjusted to a lower level, typically in the microwatt range, during actual testing to ensure test accuracy.

[0046] In this embodiment, the output wavelength of the pump light source 21 can be selected based on the dopant medium of the active fiber 5 being tested. For example, for ytterbium-doped fiber, the pump light source wavelength can be a semiconductor laser with a wavelength of 915nm or 976nm; for erbium-ytterbium co-doped fiber, the pump light source wavelength can be a semiconductor laser with a wavelength of 940nm. The pump light output power is adjustable from 0 to 100W. By adjusting the pump power, the pump power injected into the fiber under test can be adjusted to ensure a high and uniform inversion rate of the dopant ions in the active fiber.

[0047] The signal light beam splitter 13 is a Y-branch type optical beam splitter with a splitting ratio of 1:N. The optical fiber model at the input end of the signal light beam splitter 13 matches the pigtail of the indicator light source. For example, the pigtail of the indicator light source is usually a 10 / 125 single-mode optical fiber, so the input fiber of the signal light beam splitter 13 is a 10 / 125 single-mode optical fiber, and each output end of the signal light beam splitter 13 is a 10 / 125 single-mode optical fiber, which is mainly used to transmit signal light.

[0048] The number of output ends of the pump light beam splitter 23 is the same as the number of output ends of the signal light beam splitter 13. The fiber model of the input end of the pump light beam splitter 23 matches the pump light source pigtail. For example, the pump light source pigtail is usually a 105 / 125 multimode fiber. The fiber model of the input end of the pump light beam splitter 23 is a 105 / 125 multimode fiber, ensuring that the pump light can be better coupled into the input fiber of the beam splitter. Each output end of the pump light beam splitter 23 is a 105 / 125 multimode fiber.

[0049] Each signal pump combiner 31 has two input ports, one with a pump fiber and the other with a signal fiber. Its pump fiber matches the output fiber of the pump beam splitter 23. Typically, if the output fiber of the pump beam splitter 23 is a 105 / 125 multimode fiber, then the pump fiber of the signal pump combiner is also a 105 / 125 multimode fiber. Its signal fiber matches the output fiber of the signal beam splitter 13. Typically, if the output fiber of the signal beam splitter 13 is a 10 / 125 single-mode fiber, then the signal fiber of the signal pump combiner 31 is also a 10 / 125 single-mode fiber. The output fiber size of the signal pump combiner 31 must match the size of the active fiber 5 to be tested. Typically, if the active fiber 5 to be tested is a 10 / 125 double-clad active fiber, then the output fiber of the signal pump combiner 31 is a 10 / 125 double-clad passive fiber. This ensures that the pump light is injected into the inner cladding of the active fiber 5 with low loss, and the signal light is injected into the core of the active fiber 5 with low loss. This is merely an example, and the matching relationship is conventional in the art. The optical fibers at the input and output ends of the signal light beam splitter 13 can be adjusted according to the specific active fiber 5 to be tested, thus ensuring universal applicability.

[0050] Similarly, the fiber size at the input end of the optical stripper 32 needs to match the active optical fiber 5 to be tested. Typically, if the active optical fiber 5 to be tested is a 10 / 125 double-clad active optical fiber, the input end of the optical stripper 32 connected to its output end is a 10 / 125 double-clad passive optical fiber, which removes the residual pump light in the optical fiber cladding and retains the indicator light in the fiber core.

[0051] The optical fiber filter 33 has a transmittance exceeding 95% at the wavelength of the indicator light (for example, 635 nm in this embodiment), while remaining wavelengths are virtually impermeable. Because some pump light propagates within the fiber core after passing through the optical stripper 32, the pump light power, compared to the indicator light power, affects the photodarkening test results. To further improve the signal-to-noise ratio and enhance the usability of the test platform, an optical fiber filter 33 is added before the optical power meter to further attenuate the pump light. This embodiment eliminates existing spatial filters in favor of optical fiber filter 33, significantly improving the anti-interference performance of the indicator light monitoring power compared to spatial filters in existing systems. Because optical fiber filters are optical fiber devices, they have a simpler structure than spatially placed filters, require no tooling support, and are less susceptible to vibration interference. Furthermore, because the monitoring band is short-wavelength, the output power of the spatial output filter structure is easily affected by natural light.

[0052] The optical power meter 41 has a measuring range of 3W and a wavelength band of 200-1100nm. The detection band of the power meter covers the wavelength of the indicator light in the shortwave band. It can simultaneously monitor the size of the output indicator light power of multiple channels and is connected to the data processing unit 42. It can record and store the changes in the output indicator light power in real time.

[0053] In some test scenarios, not all active fiber test branches can be used for every test. When there are some active fiber test branches without active fibers 5 to be tested, a light absorbing shell 34 can be set at the output end of the signal pump combiner 31, such as Figure 2 As shown, this prevents laser emission from interfering with the test.

[0054] This invention splits the indicator light and pump light into multiple paths and injects them into multiple active fiber test branches. Using a single test system, the photon darkening performance of multiple groups of optical fibers can be simultaneously measured, eliminating the need to build multiple experimental devices for separate testing. This reduces equipment resource waste and shortens testing time. Furthermore, the signal pump combiner models in the branches can be diversified, and the output fibers of different signal pump combiners vary in size. Test fibers can select links with matching sizes for testing. This versatility significantly accelerates batch testing of active fiber darkening performance, significantly impacting the development of optical fibers for engineering applications.

[0055] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the claims attached to this utility model.

Claims

1. An active fiber photon darkening performance test system, characterized by: include: An indicator light input optical path is provided with a signal light beam splitter for splitting the indicator light into a plurality of sub-indicator lights; A pump light input optical path, wherein a pump light beam splitter is provided in the pump light input optical path for splitting the pump light into a plurality of sub-pump lights; An active optical fiber test optical path includes a plurality of active optical fiber test branches, wherein an input end of each active optical fiber test branch inputs one of the sub-indicator lights and one of the sub-pump lights, and the active optical fiber is tested after being combined; The signal monitoring unit includes an optical power meter, which is respectively connected to the output end of each active optical fiber test branch and is used to monitor the optical power of each active optical fiber test branch.

2. The active optical fiber photon darkening performance test system according to claim 1, characterized in that: Each of the active optical fiber test branches includes a signal pump combiner, an optical mode stripper and an optical fiber filter arranged in sequence; wherein, The two input ends of the signal pump combiner are respectively input with one of the sub-indicator lights and one of the sub-pump lights; The output end of the signal pump combiner and the input end of the optical stripper are used to connect the active optical fiber under test; the model of the signal pump combiner is adjusted according to the size of the active optical fiber under test, so that the output fiber at the output end of the signal pump combiner matches the size of the active optical fiber under test; The optical mode stripper is used to strip away the residual pump light in the optical fiber cladding of the active optical fiber and retain the indicator light in the core; Fiber filters are used to further attenuate the pump light.

3. The active optical fiber photon darkening performance test system according to claim 2, characterized in that: The active optical fiber test branch further comprises a light-absorbing housing, which is arranged at the output end of the signal pump combiner when there is no active optical fiber to be tested in the active optical fiber test branch during testing.

4. The active optical fiber photon darkening performance test system according to claim 2 or 3, characterized in that: The light transmission range of the optical fiber filter is such that the transmittance of the wavelength band where the indicator light is located is above 95%.

5. The active optical fiber photon darkening performance test system according to claim 1, characterized in that: The indicator light input optical path includes an indicator light source, a first optical isolator and the signal light beam splitter connected in sequence. The indicator light output by the indicator light source passes through the first optical isolator and then outputs the plurality of split indicator lights by the signal light beam splitter. The pump light input optical path includes a pump light source, a second optical isolator and the pump light beam splitter which are optically connected in sequence. The pump light output by the pump light source passes through the second optical isolator and then outputs the plurality of branch pump lights by the pump light beam splitter.

6. The active optical fiber photon darkening performance test system according to claim 5, characterized in that: The active optical fiber is an erbium-ytterbium co-doped optical fiber; the pump light source is a semiconductor pump laser with a wavelength of 940nm, and the output power is adjustable from 0 to 100W.

7. The active optical fiber photon darkening performance test system according to claim 5, characterized in that: The active optical fiber is an ytterbium-doped optical fiber; the pump light source is a semiconductor pump laser with a wavelength of 915nm or 976nm, and the output power is adjustable from 0W to 100W.

8. The active optical fiber photon darkening performance test system according to claim 1, characterized in that: The optical power meter is a multi-channel optical power meter, and the output end of each active optical fiber test branch is respectively connected to a channel of the optical power meter.

9. The active optical fiber photon darkening performance test system according to claim 1 or 5, characterized in that: The signal monitoring unit further includes a data processing unit electrically connected to the optical power meter.

10. The active optical fiber photon darkening performance test system according to claim 5, characterized in that: The indicating light source is a monochromatic laser light source with a wavelength of 200nm-1100nm.

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