A device and method for testing optical fiber microbend loss in OPLC cable

Abstract

The present invention discloses a device and method for testing the microbend loss of optical fiber in OPLC cable, the device includes an optical fiber microbend model and an optical power meter, etc. During the test, the microbend model is set on a displacement platform, and the single-mode optical fiber to be tested passes through the optical fiber microbend model. The displacement platform controller is used to adjust the displacement size of the displacement platform so that the single-mode optical fiber is clamped between the fixed end and the movable end of the displacement platform; the two ends of the single-mode optical fiber are respectively connected to the light source and the optical power meter through optical fiber jumpers, and different optical powers are obtained by moving the displacement platform and stored on a computer. The present invention uses 3D printing technology to accurately produce a variety of microbend models, solving the problem that the existing microbend test methods are difficult to achieve accuracy, efficiency, and repeatability; the computer controls the coordinated movement of the displacement platform and the microbend model, and the single-mode optical fiber is squeezed with different degrees of accuracy to achieve different microbend effects, solving the technical problem that the existing technology lacks experimental and theoretical basis.

Description

Technical Field

[0001] The invention belongs to the technical field of optical fiber detection, and in particular relates to a device and a method for testing optical fiber microbend loss in an OPLC cable. Background Art

[0002] The power fiber-to-the-home project based on optical fiber composite low-voltage cable (OPLC) utilizes power channel resources to achieve deep integration of power grid and communication network infrastructure, which is an effective way to realize information communication of energy Internet. However, the optical fiber in the OPLC cable works under the condition of superposition of thermal field and stress field for a long time, and the attenuation degradation of the optical fiber directly affects the optical fiber transmission capacity and the service life of OPLC. However, there is a lack of research on the attenuation change characteristics of the optical fiber in the OPLC cable under this superposition environment, and it is necessary to test the loss of macrobending and microbending of the optical fiber in the OPLC cable caused by the increase in temperature.

[0003] Although many research institutions have done a lot of research on optical fiber microbend loss and proposed some test methods, all test methods are relatively single in microbend test type, lack theoretical support, and the results cannot be compared with simulation software. For example, the existing expandable cylinder method: a layer of sandpaper is covered on a cylinder, the optical fiber is wound on it, and then the optical fiber is heated and expanded to observe its attenuation characteristic curve. Compared with the similar fixed diameter cylinder method, these two methods are not only relatively expensive and have poor repeatability, but also lack theoretical support. They are simply testing microbend loss. Another example is the metal grid method and the metal grid marking line method. Although the cost is relatively low, their test microbend type is single and is not suitable for analyzing the cause of optical fiber microbend loss.

[0004] Therefore, the existing methods cannot simply and theoretically support the testing of optical fiber microbend loss, and the existing devices lack accurate, efficient and repeatable test models. These problems are problems that technicians need to solve now. Summary of the invention

[0005] The purpose of the present invention is to provide a device and method for testing optical fiber microbend loss in OPLC cable, the device is simple to test and easy to operate. The method is simple, highly repeatable, can test multiple microbend types, and the measurement results are highly consistent with the simulation results.

[0006] The present invention is achieved by adopting the following technical solutions:

[0007] A device for testing optical fiber microbend loss in OPLC cable, comprising an optical fiber microbend model, a displacement platform, a single-mode optical fiber to be tested, an optical fiber jumper, a displacement platform controller, a light source and an optical power meter; wherein:

[0008] During the test, the optical fiber micro-bend model is set on the displacement platform, and the single-mode optical fiber to be tested passes through the micro-bend model. The displacement platform controller is used to adjust the displacement size of the displacement platform so that the single-mode optical fiber is clamped between the fixed end and the movable end of the displacement platform; the two ends of the single-mode optical fiber are respectively connected to the light source and the optical power meter through optical fiber jumpers, and different optical powers are obtained by moving the displacement platform and stored on the computer.

[0009] A further improvement of the present invention is that the optical fiber micro-bend models are arranged in pairs, and each pair of micro-bend models is 3D printed, with two pieces matching each other up and down, including positioning holes that match the positioning columns, and the tooth spacing size, number, length and curvature radius of the micro-bend models are different.

[0010] A further improvement of the present invention is that the minimum displacement of the displacement platform is 1 μm.

[0011] A method for testing optical fiber microbending loss in an OPLC cable, the method being based on the above-mentioned device for testing optical fiber microbending loss in an OPLC cable, comprising:

[0012] First, the two ends of the single-mode optical fiber to be tested are respectively fused with one end of a fiber jumper, the micro-bend model is fixed in the middle of the displacement platform, the single-mode optical fiber passes through the micro-bend model, the other end of one fiber jumper is connected to the light source, and the other end of the other fiber jumper is connected to the optical power meter, the light source is turned on, and the initial value of the optical power meter is recorded; the computer controls the displacement of the displacement platform through the displacement platform controller, and records the value of the optical power meter at this time; ten times the logarithm of the two optical power values ​​is the optical fiber attenuation of the single-mode optical fiber to be tested under different micro-bend conditions.

[0013] A further improvement of the present invention is that the optical fiber microbend model adopts a toothed microbend loss model.

[0014] A further improvement of the present invention is that the single-mode optical fiber to be tested is placed between toothed microbend loss models to generate microbends, and the toothed microbend loss models bend the single-mode optical fiber to generate microbends for analyzing attenuation loss; the optical transmission path will be similar to a sine wave, but not completely a sine wave; the wave is somewhere between a sine wave and a triangular wave, and the wave equation is determined by Fourier transforming the triangular wave and considering the third harmonic;

[0015] The wave equation of the triangular wave is shown in formula (1):

[0016]

[0017] Where A is the amplitude of the triangular wave, ∧ is the period; and the Fourier series of the triangular wave is shown in formula (2):

[0018]

[0019] Solving the Fourier series of the triangular wave, including the third harmonic, the wave equation is shown in formula (3):

[0020]

[0021] The relationship between optical fiber microbending loss and displacement is shown in formula (4):

[0022]

[0023] Where γ is the loss coefficient.

[0024] The present invention has the following beneficial technical effects:

[0025] The present invention provides a device for testing the microbend loss of optical fiber in an OPLC cable. Due to the use of a high-precision displacement platform, the displacement distance can be input in the control software in the computer, and the operation is simple. Moreover, the distance of each displacement is at the millimeter level, and the accuracy is relatively high. In addition, the microbend model used in the present invention can be replaced after 3D printing according to the microbend effect of different requirements, which greatly improves the accuracy of the microbend. Therefore, compared with the existing detection device, the device for detecting the microbend loss of optical fiber of the present invention is simple to operate, has high accuracy, and has many types of microbends.

[0026] The present invention provides a method for testing optical fiber microbend loss in OPLC cable. Compared with the traditional method, the detection method of the present invention has strong theoretical and research characteristics and more reliable results. Since different types of microbend models are used to achieve the microbend effect, the microbend model can be derived through formulas, and then the optical fiber microbend loss results can be obtained through simulation calculations. At the same time, the results are compared with experimental results, and the results are more reliable, supported by theory, and more research-oriented. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the optical fiber microbend loss test system.

[0028] Figure 2 It is the functional block diagram of the optical fiber microbend loss test system.

[0029] Figure 3 It is a side view of the optical fiber microbend loss test system.

[0030] Figure 4 It is a top view of the optical fiber microbend loss test system.

[0031] Figure 5 This is the three-view diagram of the optical fiber microbend model. Figure 5 (a) Main view, Figure 5 (b) is a top view, Figure 5 (c) is a side view.

[0032] Figure 6 This is a test result diagram of optical fiber microbend loss under different tooth spacings of the present invention.

[0033] Figure 7 It is a comparison chart of the optical fiber microbend loss test and theoretical calculation results when the tooth spacing is 4 mm in the present invention.

[0034] Description of reference numerals:

[0035] 1. Fiber microbend model, 2. Displacement platform, 3. Single-mode fiber to be tested, 4. Fiber jumper, 5. Displacement platform controller, 6. Light source, 7. Optical power meter. DETAILED DESCRIPTION

[0036] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0037] Part I:

[0038] like Figures 1 to 5 As shown, the present invention provides a device for testing the optical fiber microbend loss in an OPLC cable, comprising multiple types of paired optical fiber microbend models 1, a displacement platform 2, a single-mode optical fiber to be tested 3, an optical fiber jumper 4, a displacement platform controller 5, a light source 6, and an optical power meter 7. During the test, the displacement platform 2 is precisely controlled by the displacement platform controller 5 on a computer, the single-mode optical fiber 3 to be tested is connected to the light source 6 and the optical power meter 7 respectively through the optical fiber jumper 4, and different optical powers are obtained by moving the displacement platform 2 and stored on the computer.

[0039] Part II:

[0040] The method for testing different types of microbend losses of optical fibers in OPLC cables using the device of the present invention is to place the required equipment as follows: Figure 3 Installation and debugging, the specific test method is as follows:

[0041] (1) The two ends of a 1 m single-mode optical fiber 3 are first fusion-spliced ​​with the optical fiber jumper 4.

[0042] (2) Fix the optical fiber microbend model 1 in the middle of the displacement platform 2.

[0043] (3) The single-mode optical fiber 3 to be tested is passed through the optical fiber microbend model 1, and the displacement of the displacement platform 2 is adjusted by the displacement platform controller 5, so that the single-mode optical fiber 1 is clamped between the fixed end and the movable end of the displacement platform 2.

[0044] (4) Connect one end of the optical fiber jumper 4 to the high-stability light source 6 , and connect the other end of the optical fiber jumper 4 to the optical power meter 7 .

[0045] (5) Turn on the light source 6 and record the initial value of the optical power meter 7.

[0046] (6) The displacement of the displacement platform 2 is controlled by the displacement platform controller 5, and the value of the optical power meter 7 at this time is recorded.

[0047] (7) Repeat step (5), each time for 15 minutes, and record the optical power values ​​in turn.

[0048] (8) The difference between step (5) and step (6) is the microbending loss magnitude of different microstrains in step (6).

[0049] (9) If a different type of optical fiber microbend model 1 is required, the microbend model 1 in step (2) only needs to be replaced with the required model.

[0050] The purpose of step (1) is to overcome the optical power fluctuation caused by the traditional optical fiber coupler, which affects the experimental results.

[0051] Step (2) In order to ensure the high accuracy of the microbend model, multiple types of microbend models are first designed and the models are printed using 3D printing technology. Since the accuracy of 3D is 0.1 mm, the accuracy of the microbend model can be guaranteed.

[0052] Step (2) uses an electric displacement platform, which can control the different micro-strain sizes of the optical fiber by changing the displacement size.

[0053] The light source in step (3) adopts a high-stability light source to ensure that the optical power fluctuation caused by the light source is minimized.

[0054] Part III:

[0055] In order to form microbends in the optical fiber, the present invention designs a toothed microbend loss model. The single-mode optical fiber 3 is placed between these toothed microbend loss models to generate microbends. The toothed microbend loss model bends the single-mode optical fiber 3 to generate microbends for analyzing attenuation loss. The path of the wave will be similar to a sine wave, but not completely a sine wave. The wave is somewhere between a sine wave and a triangular wave. By Fourier transforming the triangular wave and considering the third harmonic, the wave equation is determined.

[0056] The wave equation of the triangular wave is shown in formula (1):

[0057]

[0058] Where A is the amplitude of the triangular wave, ∧ is the period; and the Fourier series of the triangular wave is shown in formula (2):

[0059]

[0060] Solving the Fourier series of the triangular wave, including the third harmonic, the wave equation is shown in formula (3):

[0061]

[0062] The relationship between optical fiber microbending loss and displacement is shown in formula (4):

[0063]

[0064] Where γ is the loss coefficient.

[0065] Part 4:

[0066] The method of using different types of microbend losses of optical fibers in OPLC cables is compared with the results in MATLAB simulation.

[0067] The light source is 1550nm, the single-mode fiber model G.652.D is 1m long, the displacement of the displacement platform is 0.1mm, and each test time is 15min. The fiber attenuation test results of the fiber microbend model with different tooth spacing are as follows Figure 6 As shown in the figure, the fiber loss test of single-mode fiber under 6 different microbends shows that when the displacement stage moves the same distance, the smaller the tooth spacing, the greater the fiber loss. Comparison of the experimental test and theoretical calculation results of the fiber attenuation of the fiber microbend model with a tooth spacing of 4mm Figure 7 As shown in the figure, the optical fiber loss data under different stage moving distances have good consistency between the theoretical value and the experimental value.

Claims

1. A method for testing optical fiber microbend loss in OPLC cable, characterized in that: The method is based on a device for testing optical fiber microbend loss in an OPLC cable, the device comprising an optical fiber microbend model (1), a displacement platform (2), a single-mode optical fiber to be tested (3), an optical fiber jumper (4), a displacement platform controller (5), a light source (6) and an optical power meter (7); wherein during testing, the optical fiber microbend model (1) is arranged on the displacement platform (2), the single-mode optical fiber to be tested (3) passes through the optical fiber microbend model (1), the displacement platform controller (5) is used to adjust the displacement size of the displacement platform (2), so that the single-mode optical fiber to be tested (3) is clamped between the fixed end and the movable end of the displacement platform (2); the two ends of the single-mode optical fiber to be tested (3) are respectively connected to the light source (6) and the optical power meter (7) through the optical fiber jumper (4); the displacement platform (2) is used to move so that the single-mode optical fiber to be tested (3) produces different microbend deformations, the optical power under different microbend conditions is measured by the optical power meter (7), and the optical power is stored in a computer; The method includes: First, the two ends of the single-mode optical fiber (3) to be tested are respectively fused with one end of an optical fiber jumper, the optical fiber micro-bend model (1) is fixed in the middle of the displacement platform (2), the single-mode optical fiber (3) to be tested passes through the optical fiber micro-bend model (1), the other end of an optical fiber jumper (4) is connected to the light source (6), the other end of another optical fiber jumper (4) is connected to the optical power meter (7), the light source (6) is turned on, and the initial value of the optical power meter (7) is recorded; the computer controls the displacement of the displacement platform (2) through the displacement platform controller (5), and records the value of the optical power meter (7) at this time; the ten times the logarithm of the two optical power values ​​is the optical fiber attenuation of the single-mode optical fiber (3) to be tested under different micro-bend conditions; The microbend model (1) adopts a toothed microbend loss model; the single-mode optical fiber (3) to be tested is placed between the toothed microbend loss models to generate microbends, and the toothed microbend loss model bends the single-mode optical fiber (3) to be tested to generate microbends for analyzing attenuation loss; the optical transmission path will be similar to a sine wave, but not completely a sine wave; the wave is somewhere between a sine wave and a triangular wave, and the wave equation is determined by Fourier transforming the triangular wave and considering the third harmonic, thereby calculating the microbend loss; The triangular wave equation is shown in formula (1): Where A is the amplitude of the triangular wave, ∧ is the period; and the Fourier series of the triangular wave is shown in formula (2): Solving the Fourier series of the triangle wave, including the third harmonic, the equation is shown in formula (3): The relationship between optical fiber microbending loss and displacement is shown in formula (4): Where γ is the loss coefficient.

2. A method for testing optical fiber microbend loss in an OPLC cable according to claim 1, characterized in that: The optical fiber microbend models (1) are arranged in pairs. Each pair of optical fiber microbend models (1) is formed by 3D printing, and the two pieces match each other up and down, and include positioning holes for matching positioning columns. The tooth spacing size, number, length and curvature radius of the optical fiber microbend models (1) are different.

3. A method for testing optical fiber microbend loss in an OPLC cable according to claim 1, characterized in that: The minimum displacement of the displacement platform (2) is 1 μm.

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