Single-mode optical fiber multi-parameter synchronous measurement method and system based on OTDR (Optical Time Domain Reflectometer)

Abstract

The invention provides a single-mode optical fiber multi-parameter synchronous measurement method based on an OTDR (Optical Time Domain Reflectometer). The method comprises the following steps: generating an optical pulse signal; injecting the optical pulse signal into a forward optical path to generate a forward first backward Rayleigh scattering light power signal, and injecting the optical pulse signal into a reverse optical path to generate a reverse second backward Rayleigh scattering light power signal; converting the first back Rayleigh scattering light power signal photoelectric signal and the second back Rayleigh scattering light power signal photoelectric signal into two electric signals; the two electric signals are converted into two digital signals through analog-to-digital conversion; drawing a back Rayleigh scattering power distribution diagram based on the two digital signals, and calculating a plurality of parameter values of the measured optical fiber through a data model in combination with the plurality of parameter values of the first reference optical fiber and the second reference optical fiber; wherein the forward light path is from the first reference optical fiber, the to-be-measured optical fiber to the second reference optical fiber, and the reverse light path is opposite to the first reference optical fiber and the to-be-measured optical fiber. According to the invention, the multi-parameter synchronous measurement of the single-mode fiber can be realized, and the measurement cost and complexity are obviously reduced.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber technology, and in particular to a single-mode optical fiber multi-parameter synchronous measurement method and system based on OTDR (Optical Time-Domain Reflectometer). Background Art

[0002] With the rapid development of modern communication services, the demand for transmission capacity continues to increase, which has promoted the research hotspot of new optical fiber transmission technology. Space-Division Multiplexing (SDM) represented by multi-core fiber and few-mode fiber is a new way to break through the capacity bottleneck of single-mode optical fiber system. By making full use of the spatial dimension, it can double the system transmission capacity and become one of the core technologies for realizing Tbit / s or even Pbit / s level transmission in the future. However, the current space-division multiplexing transmission technology is still in the laboratory research stage and has not yet been widely used in actual scenarios. In order to further improve the spectral efficiency of optical fiber systems and reduce the transmission cost per bit, the application of high-dimensional modulation methods has become the key, which puts higher requirements on the loss, linearity and other performance of optical fiber.

[0003] At present, a variety of technical solutions have been developed for the measurement of different optical fiber parameters. For example, dispersion measurement usually uses the time domain method, frequency domain method and backscattering method; optical fiber loss measurement mainly relies on the truncation method and backscattering method; the measurement of effective mode field area and mode field diameter often uses the near-field scanning method, far-field scanning method and variable aperture method; the refractive index distribution can be achieved through near-field scanning, longitudinal interference, focusing method and backscattering method; the cutoff wavelength of optical fiber can be measured by the transmission power method and other technologies.

[0004] From the current research progress, there are already a lot of measurement methods for various optical fiber parameters, and they have reached a high level in terms of measurement accuracy and stability. However, these measurement methods generally have the limitation of only being able to measure a single parameter, and it is difficult to meet the needs of measuring multiple parameters at the same time. In addition, some measurement schemes are high in cost and system complexity, and cannot effectively measure the distribution characteristics of parameters.

[0005] Therefore, there is an urgent need to develop a new method that is simple, economical and can achieve synchronous measurement of multiple parameters in optical fibers. Summary of the invention

[0006] The technical problem to be solved by the embodiments of the present invention is to provide a single-mode optical fiber multi-parameter synchronous measurement method and system based on OTDR, which can realize multi-parameter synchronous measurement of single-mode optical fiber and significantly reduce the measurement cost and complexity.

[0007] In order to solve the above technical problems, an embodiment of the present invention provides a single-mode optical fiber multi-parameter synchronous measurement method based on OTDR, and a single-mode optical fiber multi-parameter synchronous measurement system based on OTDR is used to perform multi-parameter synchronous measurement on a measured optical fiber with a first reference optical fiber and a second reference optical fiber connected at both ends. The method comprises the following steps:

[0008] generating an optical pulse signal;

[0009] Injecting the optical pulse signal into a preset forward optical path to generate a forward first back-Rayleigh scattered optical power signal; and injecting the optical pulse signal into the preset reverse optical path to generate a reverse second back-Rayleigh scattered optical power signal; wherein the forward optical path is a path from which the signal is injected from the first reference optical fiber and passes through the optical fiber to be tested to the second reference optical fiber; and the reverse optical path is a path from which the signal is injected from the second reference optical fiber and passes through the optical fiber to be tested to the first reference optical fiber;

[0010] Performing photoelectric signal conversion on the first back-scattered Rayleigh light power signal and the second back-scattered Rayleigh light power signal to form two electrical signals;

[0011] Performing analog-to-digital conversion on the two formed electrical signals to obtain two digital signals;

[0012] Based on the two digital signals obtained, a corresponding backscattering power distribution diagram is drawn, and multiple parameter values ​​of the first reference optical fiber and the second reference optical fiber are combined to calculate multiple parameter values ​​of the measured optical fiber through a preset data model.

[0013] The optical pulse signal is a stable optical pulse signal specified within the range of a central wavelength of 1550 nm, a pulse optical power of 0 to 40 mW, a pulse width of 10 to 1200 ns, and a repetition frequency of 1 to 100 kHz.

[0014] The first reference optical fiber, the second reference optical fiber and the optical fiber under test have the same parameters, including mode field diameter, effective mode field area, core diameter, effective refractive index and cut-off wavelength.

[0015] Wherein, the method further comprises:

[0016] A human-computer interaction instruction is received to control the pulse power, pulse width and repetition frequency of the optical pulse signal, and to save the first back-scattered Rayleigh light power signal and the second back-scattered Rayleigh light power signal.

[0017] The embodiment of the present invention also provides a single-mode optical fiber multi-parameter synchronous measurement system based on OTDR, which performs multi-parameter synchronous measurement on a measured optical fiber with a first reference optical fiber and a second reference optical fiber connected at both ends, including:

[0018] An optical pulse generating module, used for generating an optical pulse signal;

[0019] An optical path module, used for injecting the optical pulse signal into a preset forward optical path to generate a forward first back-Rayleigh scattered optical power signal; and injecting the optical pulse signal into the preset reverse optical path to generate a reverse second back-Rayleigh scattered optical power signal; wherein the forward optical path is a path from which the signal is injected from the first reference optical fiber and passes through the optical fiber to be tested to the second reference optical fiber; and the reverse optical path is a path from which the signal is injected from the second reference optical fiber and passes through the optical fiber to be tested to the first reference optical fiber;

[0020] a photoelectric detection module, configured to perform photoelectric signal conversion on the first back-scattered Rayleigh light power signal and the second back-scattered Rayleigh light power signal to form two electrical signals;

[0021] A data acquisition module is used to perform analog-to-digital conversion on the two generated electrical signals to obtain two digital signals;

[0022] The main control module is used to draw a corresponding backscattering power distribution diagram based on the two digital signals obtained, and calculate multiple parameter values ​​of the measured optical fiber through a preset data model in combination with multiple parameter values ​​of the first reference optical fiber and the second reference optical fiber.

[0023] The optical pulse signal is a stable optical pulse signal specified within the range of a central wavelength of 1550 nm, a pulse optical power of 0 to 40 mW, a pulse width of 10 to 1200 ns, and a repetition frequency of 1 to 100 kHz.

[0024] The first reference optical fiber, the second reference optical fiber and the optical fiber under test have the same parameters, including mode field diameter, effective mode field area, core diameter, effective refractive index and cut-off wavelength.

[0025] Among them, it also includes: human-computer interaction module; among them,

[0026] The human-computer interaction module is used to receive user instructions to generate human-computer interaction instructions, so that the main control module controls the pulse power, pulse width and repetition frequency of the optical pulse signal on the optical pulse generating module.

[0027] Implementing the embodiments of the present invention has the following beneficial effects:

[0028] The present invention injects optical pulse signals into the optical fiber under test through a forward optical path and a reverse optical path respectively to form a first back-scattered Rayleigh light power signal and a second back-scattered Rayleigh light power signal, and combines multiple parameter values ​​of the first reference optical fiber and the second reference optical fiber to obtain multiple parameter values ​​of the optical fiber under test through a data model. Not only is the measurement process and the calculation process simple, but also the multi-parameter synchronous measurement of the single-mode optical fiber can be realized, which significantly reduces the measurement cost and complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the present invention.

[0030] Figure 1 A schematic diagram of the structure of a single-mode optical fiber multi-parameter synchronous measurement system based on OTDR provided in an embodiment of the present invention;

[0031] Figure 2 A specific deployment diagram of a single-mode optical fiber multi-parameter synchronous measurement system based on OTDR in an application scenario provided by an embodiment of the present invention;

[0032] Figure 3 A back-Rayleigh scattering result diagram drawn by a forward first back-Rayleigh scattering light signal and a back-Rayleigh scattering result diagram drawn by a reverse second back-Rayleigh scattering light signal in an application scenario of an OTDR-based single-mode optical fiber multi-parameter synchronous measurement system provided by an embodiment of the present invention;

[0033] Figure 4 A test result diagram of the mode field diameter and core diameter of a measured optical fiber in an application scenario of an OTDR-based single-mode optical fiber multi-parameter synchronous measurement system provided in an embodiment of the present invention;

[0034] Figure 5 The present invention provides a flowchart of a method for synchronously measuring multiple parameters of a single-mode optical fiber based on OTDR. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0036] like Figure 1As shown in the figure, a single-mode optical fiber multi-parameter synchronous measurement system based on OTDR is provided in an embodiment of the present invention, which performs multi-parameter synchronous measurement on a measured optical fiber with a first reference optical fiber (such as reference optical fiber A) and a second reference optical fiber (such as reference optical fiber B) connected at both ends, including a main control module 201, an optical pulse generating module 202, an optical path module 203, a photoelectric detection module 204 and a data acquisition module 205; wherein,

[0037] The optical pulse generating module 202 is used to generate an optical pulse signal; at this time, the optical pulse signal is a stable optical pulse signal specified within the range of 1550nm, 0-40mW pulse optical power, 10-1200ns pulse width, and 1-100kHz repetition frequency; for example, the optical pulse signal has a central wavelength of 1550nm, a pulse optical power of 20mW, a pulse width of 100ns, and a repetition frequency of 10kHz;

[0038] The optical path module 203 is used to inject the optical pulse signal (such as through a single-mode circulator) into a preset forward optical path to generate a forward first backscattered Rayleigh scattered optical power signal P bs (z); and, injecting the optical pulse signal into a preset reverse optical path to generate a reverse second backscattered Rayleigh light power signal P′ bs (z); wherein the forward optical path is the path from which the signal is injected from the first reference optical fiber and passes through the optical fiber to be tested to the second reference optical fiber; the reverse optical path is the path from which the signal is injected from the second reference optical fiber and passes through the optical fiber to be tested to the first reference optical fiber;

[0039] The photoelectric detection module 204 is used to detect the first backscattered Rayleigh light power signal P bs (z) and the second backscattered Rayleigh light power signal P′ bs (z) Convert the photoelectric signal to form two electrical signals P bs' (z), P′ bs' (z);

[0040] The data acquisition module 205 is used to generate the two electrical signals P bs' (z), P′ bs' (z) Perform analog-to-digital conversion to obtain two digital signals P bs‘' (z), P′ bs'’ (z);

[0041] The main control module 201 is used to obtain two digital signals P bs‘' (z), P′ bs'’(z), draw the corresponding backscattering power distribution diagram, and combine the multiple parameter values ​​of the first reference fiber and the second reference fiber to calculate the multiple parameter values ​​of the measured fiber through a preset data model; wherein the first reference fiber, the second reference fiber and the measured fiber have the same parameters, and the parameters of the three include the mode field diameter 2w(z), the effective mode field area A eff (z), fiber diameter a(z), effective refractive index Δ(z) and cut-off wavelength λ c (z).

[0042] In an embodiment of the present invention, the system further includes: a human-computer interaction module 200; wherein the human-computer interaction module 200 is used to receive user instructions to generate human-computer interaction instructions to allow the main control module 201 to control the pulse power, pulse width and repetition frequency of the optical pulse signal on the optical pulse generating module 202.

[0043] like Figures 2 to 4 The application scenario of a single-mode optical fiber multi-parameter synchronous measurement system based on OTDR provided in an embodiment of the present invention is further described as follows:

[0044] exist Figure 2 In the process, the operator connects the measured optical fiber 8 with the first reference optical fiber 6 and the second reference optical fiber 10 by fusing and splicing the optical fiber connectors 7 and 9, and then sets the pulse width of the pulse laser 3 (i.e., the optical pulse generating module 202) to 100ns and the repetition frequency to 10kHz optical pulse signal through the UP Squared board x86 main control board 2 (i.e., the main control module 201).

[0045] At this time, the optical pulse signal generated by the pulse laser 3 is transmitted from port 1 to port 2 of the single-mode circulator 4. If port 2 of the single-mode circulator 4 is connected to port A, the optical pulse signal is transmitted through the first reference optical fiber 6 to the optical fiber under test 8 to the second reference optical fiber 10 to obtain the first forward back Rayleigh scattered optical power signal. At this time, the optical power signal is transmitted from port 2 to port 3 of the single-mode circulator to the photoelectric detector 11 (i.e., the photoelectric detection module 204) to be converted into an electrical signal and then transmitted to the data acquisition card 12 (i.e., the data acquisition module 205) to be converted into a digital signal. The operator controls the UP Squared board x86 main control board 2 through the human-computer interaction module 1 (i.e., the human-computer interaction module 200) to save the digital signal to the storage unit.

[0046] Similarly, if port 2 of the single-mode circulator 4 is connected to port B, the transmission path of the optical pulse signal is changed, and the above operation is repeated, the obtained reverse second back Rayleigh scattered optical power signal is also stored in the storage unit.

[0047] Finally, the digital signal stored in the UP Squared board x86 main control board 2 is called through the human-computer interaction module 1 to draw the positive and negative backscattering power distribution diagrams, and the parameters of the first reference optical fiber 6 and the second reference optical fiber 10 are input into the human-computer interaction module 1 to control the UP Squared board x86 main control board 2 to calculate the data according to the pre-established mathematical model, obtain the relevant parameters of the measured optical fiber 8 and draw the relevant parameter diagram.

[0048] exist Figure 3 In the test, according to the optical pulse signal with the pulse width set to 100ns and the repetition frequency set to 10kHz, the back-Rayleigh scattering result graph drawn by the forward first back-Rayleigh scattering light signal and the back-Rayleigh scattering result graph drawn by the reverse second back-Rayleigh scattering light signal were obtained.

[0049] exist Figure 4 In, based on Figure 3 The first and second back-scattered Rayleigh light signals in the forward and reverse directions are input into the mode field diameters 2w(z) of the first reference optical fiber 6 and the second reference optical fiber 10, which are 10.2μm and 9.88μm, respectively, and the core diameters a(z) are 8.25μm and 8.28μm, respectively. The mode field diameter 2w(z) and the core diameter a(z) of the measured optical fiber 8 are calculated to be 9.24μm and 8.28μm, respectively, which are very close to the actual mode field diameter 2w(z) of the measured optical fiber of 9.21μm and the core diameter a(z) of 8.25μm.

[0050] like Figure 5 As shown in the figure, a single-mode optical fiber multi-parameter synchronous measurement method based on OTDR is provided in an embodiment of the present invention. The single-mode optical fiber multi-parameter synchronous measurement system based on OTDR in the embodiment of the present invention is used to perform multi-parameter synchronous measurement on the optical fiber under test with the first reference optical fiber and the second reference optical fiber connected at both ends. The method comprises the following steps:

[0051] Step S1, generating an optical pulse signal;

[0052] Step S2, injecting the optical pulse signal into a preset forward optical path to generate a forward first back Rayleigh scattered optical power signal; and injecting the optical pulse signal into the preset reverse optical path to generate a reverse second back Rayleigh scattered optical power signal; wherein the forward optical path is a path from which the signal is injected from the first reference optical fiber and passes through the optical fiber to be tested to the second reference optical fiber; and the reverse optical path is a path from which the signal is injected from the second reference optical fiber and passes through the optical fiber to be tested to the first reference optical fiber;

[0053] Step S3, performing photoelectric signal conversion on the first backscattered Rayleigh light power signal and the second backscattered Rayleigh light power signal to form two electrical signals;

[0054] Step S4, performing analog-to-digital conversion on the two generated electrical signals to obtain two digital signals;

[0055] Step S5: based on the two digital signals obtained, draw a corresponding backscattering power distribution diagram, and combine the multiple parameter values ​​of the first reference optical fiber and the second reference optical fiber to calculate the multiple parameter values ​​of the measured optical fiber through a preset data model.

[0056] The optical pulse signal is a stable optical pulse signal specified within the range of a central wavelength of 1550 nm, a pulse optical power of 0 to 40 mW, a pulse width of 10 to 1200 ns, and a repetition frequency of 1 to 100 kHz.

[0057] The first reference optical fiber, the second reference optical fiber and the optical fiber under test have the same parameters, including mode field diameter, effective mode field area, core diameter, effective refractive index and cut-off wavelength.

[0058] Wherein, the method further comprises:

[0059] A human-computer interaction instruction is received to control the pulse power, pulse width and repetition frequency of the optical pulse signal, and to save the first back-scattered Rayleigh light power signal and the second back-scattered Rayleigh light power signal.

[0060] Implementing the embodiments of the present invention has the following beneficial effects:

[0061] The present invention injects optical pulse signals into the optical fiber under test through a forward optical path and a reverse optical path respectively to form a first back-scattered Rayleigh light power signal and a second back-scattered Rayleigh light power signal, and combines multiple parameter values ​​of the first reference optical fiber and the second reference optical fiber to obtain multiple parameter values ​​of the optical fiber under test through a data model. Not only is the measurement process and the calculation process simple, but also the multi-parameter synchronous measurement of the single-mode optical fiber can be realized, which significantly reduces the measurement cost and complexity.

[0062] It is worth noting that in the above system embodiment, the various system modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of the various functional modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention.

[0063] A person skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, such as ROM / RAM, disk, CD-ROM, etc.

[0064] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for synchronously measuring multi-parameters of a single-mode optical fiber based on OTDR, characterized in that: A multi-parameter synchronous measurement system for a single-mode optical fiber based on OTDR is used to perform multi-parameter synchronous measurement on an optical fiber under test with a first reference optical fiber and a second reference optical fiber connected at both ends. The method comprises the following steps: generating an optical pulse signal; Injecting the optical pulse signal into a preset forward optical path to generate a forward first back-Rayleigh scattered optical power signal; and injecting the optical pulse signal into the preset reverse optical path to generate a reverse second back-Rayleigh scattered optical power signal; wherein the forward optical path is a path from which the signal is injected from the first reference optical fiber and passes through the optical fiber to be tested to the second reference optical fiber; and the reverse optical path is a path from which the signal is injected from the second reference optical fiber and passes through the optical fiber to be tested to the first reference optical fiber; Performing photoelectric signal conversion on the first back-scattered Rayleigh light power signal and the second back-scattered Rayleigh light power signal to form two electrical signals; Performing analog-to-digital conversion on the two formed electrical signals to obtain two digital signals; Based on the two digital signals obtained, a corresponding backscattering power distribution diagram is drawn, and multiple parameter values ​​of the first reference optical fiber and the second reference optical fiber are combined to calculate multiple parameter values ​​of the measured optical fiber through a preset data model.

2. The OTDR-based single-mode optical fiber multi-parameter synchronous measurement method according to claim 1, characterized in that: The optical pulse signal is a stable optical pulse signal specified within the range of a central wavelength of 1550nm, a pulse optical power of 0-40mW, a pulse width of 10-1200ns, and a repetition frequency of 1-100kHz.

3. The single-mode optical fiber multi-parameter synchronous measurement method based on OTDR as claimed in claim 2, characterized in that: The first reference optical fiber, the second reference optical fiber and the optical fiber under test have the same parameters, including mode field diameter, effective mode field area, core diameter, effective refractive index and cut-off wavelength.

4. The OTDR-based single-mode optical fiber multi-parameter synchronous measurement method according to claim 3, characterized in that: The method further comprises: A human-computer interaction instruction is received to control the pulse power, pulse width and repetition frequency of the optical pulse signal, and to save the first back-scattered Rayleigh light power signal and the second back-scattered Rayleigh light power signal.

5. A single-mode optical fiber multi-parameter synchronous measurement system based on OTDR, characterized in that: It performs multi-parameter synchronous measurement on a measured optical fiber with a first reference optical fiber and a second reference optical fiber connected at both ends, including: An optical pulse generating module, used for generating an optical pulse signal; An optical path module, used for injecting the optical pulse signal into a preset forward optical path to generate a forward first back-Rayleigh scattered optical power signal; and injecting the optical pulse signal into the preset reverse optical path to generate a reverse second back-Rayleigh scattered optical power signal; wherein the forward optical path is a path from which the signal is injected from the first reference optical fiber and passes through the optical fiber to be tested to the second reference optical fiber; and the reverse optical path is a path from which the signal is injected from the second reference optical fiber and passes through the optical fiber to be tested to the first reference optical fiber; a photoelectric detection module, configured to perform photoelectric signal conversion on the first back-scattered Rayleigh light power signal and the second back-scattered Rayleigh light power signal to form two electrical signals; A data acquisition module is used to perform analog-to-digital conversion on the two generated electrical signals to obtain two digital signals; The main control module is used to draw a corresponding backscattering power distribution diagram based on the two digital signals obtained, and calculate multiple parameter values ​​of the measured optical fiber through a preset data model in combination with multiple parameter values ​​of the first reference optical fiber and the second reference optical fiber.

6. The single-mode optical fiber multi-parameter synchronous measurement system based on OTDR according to claim 5, characterized in that: The optical pulse signal is a stable optical pulse signal specified within the range of a central wavelength of 1550nm, a pulse optical power of 0-40mW, a pulse width of 10-1200ns, and a repetition frequency of 1-100kHz.

7. The single-mode optical fiber multi-parameter synchronous measurement system based on OTDR according to claim 6, characterized in that: The first reference optical fiber, the second reference optical fiber and the optical fiber under test have the same parameters, including mode field diameter, effective mode field area, core diameter, effective refractive index and cut-off wavelength.

8. The single-mode optical fiber multi-parameter synchronous measurement system based on OTDR according to claim 7, characterized in that: Also includes: Human-computer interaction module; The human-computer interaction module is used to receive user instructions to generate human-computer interaction instructions, so that the main control module controls the pulse power, pulse width and repetition frequency of the optical pulse signal on the optical pulse generating module.

Images