Device and method for measuring stimulated Raman scattering threshold value of multi-core optical fiber

Abstract

The invention discloses a device and a method for measuring a stimulated Raman scattering threshold value of a multi-core optical fiber, the device comprises a pumping source, a multi-core optical fiber fan-in module, a multi-core optical fiber fan-out module, a spectrograph and an upper computer, the device measures a stimulated Raman scattering threshold value sample of each fiber core of a multi-core optical fiber sample; according to the stimulated Raman scattering threshold value sample, the effective length sample and the effective mode field area sample, fitting to obtain a stimulated Raman scattering threshold value calculation formula of the fiber core; and obtaining the effective length and the effective mode field area of each fiber core of the to-be-measured core optical fiber, and calculating the comprehensive stimulated Raman scattering threshold value of the to-be-measured multi-core optical fiber through a stimulated Raman scattering threshold value calculation formula. According to the method, the inter-core crosstalk effect is involved when the stimulated Raman scattering threshold value sample is collected, so that the stimulated Raman scattering threshold value calculation formula obtained through fitting is more suitable for the multi-core optical fiber, and the technical vacancy of calculation of the stimulated Raman scattering threshold value of the multi-core optical fiber is filled.

Description

Technical Field

[0001] The present invention relates to the technical field of stimulated Raman scattering measurement, and particularly to an apparatus and method for measuring the stimulated Raman scattering threshold of a multi-core optical fiber. Background Art

[0002] The topological structure of a digital power grid constitutes a distributed multi-level and multi-domain system. The information interaction between multiple levels of smart grid systems is one of the important technologies of a digital and intelligent power network. Optical fiber communication can achieve interconnection and interoperability in a digital power grid. It has the advantages of high transmission rate, strong stability, long transmission distance, etc., and is the preferred communication means for the interconnection and interoperability of a digital power grid.

[0003] Multi-core single-mode optical fibers can transmit high-power energy optical signals. However, due to the influence of the stimulated nonlinear scattering effect of the optical fiber, the input pump optical power at a specific wavelength is converted into other frequency components, and this part of the energy cannot be normally received by the detector at the output end of the optical fiber, resulting in an increase in energy optical loss and a decrease in optical transmission efficiency. At the same time, the output Raman Stokes optical signal generated by stimulated Raman scattering will randomly reflect back to the signal input end, which may cause a decline or even damage to the performance of the input laser. Therefore, in order to control the occurrence of stimulated Raman reflection during the optical signal transmission process, it is necessary to know the threshold of stimulated Raman scattering. The prior art knows how to calculate the stimulated Raman scattering threshold of a single-core optical fiber. For multi-core optical fibers, due to the existence of inter-core crosstalk effects, the measurement method of the stimulated Raman scattering threshold of a single-core optical fiber is not applicable to multi-core optical fibers. Currently, there is a technical gap in the calculation specifically for the stimulated Raman scattering threshold of multi-core optical fibers. Summary of the Invention

[0004] The present invention provides an apparatus and method for measuring the stimulated Raman scattering threshold of a multi-core optical fiber to fill the technical gap in the calculation specifically for the stimulated Raman scattering threshold of multi-core optical fibers.

[0005] To solve the above technical problems, an embodiment of the present invention provides an apparatus for measuring the stimulated Raman scattering threshold of a multi-core optical fiber, including: a pump source, a multi-core optical fiber fan-in module, a multi-core optical fiber fan-out module, a spectrometer, and a host computer; the multi-core optical fiber fan-in module includes a plurality of fan-in ports; the multi-core optical fiber fan-out module includes a plurality of fan-out ports;

[0006] Each of the fan-in ports is used to connect the pump source and a core of a multi-core optical fiber sample;

[0007] Each of the fan-out ports is used to connect the spectrometer and a core of the multi-core optical fiber sample;

[0008] The spectrometer is connected to the host computer;

[0009] The pump source is used to generate an optical signal and fan the optical signal into the cores of the multi-core fiber sample through the fan-in port;

[0010] The spectrometer is used to measure the scattered optical signals output from each core of the multi-core fiber sample;

[0011] The host computer is used to obtain the effective length samples and effective mode field area samples of each core of the multi-core fiber sample; determine the stimulated Raman scattering threshold samples of each core of the multi-core fiber sample according to the measurement results of the scattered optical signals of the spectrometer; fit a stimulated Raman scattering threshold calculation formula based on the stimulated Raman scattering threshold samples, effective length samples, and effective mode field area samples of all cores in the multi-core fiber sample; and,

[0012] Obtain the effective length and effective mode field area of each core of the multi-core fiber to be measured; calculate the stimulated Raman scattering threshold of each fiber in the multi-core fiber to be measured through the stimulated Raman scattering threshold calculation formula according to the effective length and effective mode field area of each core of the multi-core fiber to be measured; calculate the comprehensive stimulated Raman scattering threshold of the multi-core fiber to be measured according to the stimulated Raman scattering threshold of each fiber in the multi-core fiber to be measured.

[0013] As a preferred solution, the determining the stimulated Raman scattering threshold sample of each core of the multi-core fiber sample according to the measurement results of the scattered optical signals of the spectrometer includes:

[0014] For each core of the multi-core fiber sample, determine the power of the input optical signal corresponding to the non-linear sudden increase in the power of the scattered optical signal according to the measurement results of the scattered optical signal of the core, and use it as the stimulated Raman scattering threshold of the core.

[0015] As a preferred solution, the fitting a stimulated Raman scattering threshold calculation formula with the effective length and effective mode field area as independent variables and the stimulated Raman scattering threshold as the dependent variable according to the stimulated Raman scattering threshold samples, effective length samples, and effective mode field area samples of all cores in the multi-core fiber sample includes:

[0016] Construct a candidate formula containing several fitting parameters with the effective length and effective mode field area as independent variables and the stimulated Raman scattering threshold as the dependent variable;

[0017] Fit the candidate formula according to the stimulated Raman scattering threshold samples, effective length samples, and effective mode field area samples of all cores in the multi-core fiber sample to obtain the parameter values of each fitting parameter;

[0018] Generate a stimulated Raman scattering threshold calculation formula according to the parameter values of all fitting parameters and the candidate formula.

[0019] As a preferred solution, the candidate formula is:

[0020]

[0021] In the formula, P represents the stimulated Raman scattering threshold of the core; L represents the effective length of the core; A represents the effective mode field area of the core; g R is the Raman gain coefficient; a, b, c, and d represent fitting parameters.

[0022] As a preferred solution, the calculation formula for the comprehensive stimulated Raman scattering threshold is:

[0023]

[0024] In the formula, P CT represents the comprehensive stimulated Raman scattering threshold; P i represents the stimulated Raman scattering threshold of the i-th core; N represents the total number of cores in the multi-core optical fiber.

[0025] Based on the above embodiments, another embodiment of the present invention provides a method for measuring the stimulated Raman scattering threshold of a multi-core optical fiber, which is applicable to the multi-core optical fiber stimulated Raman scattering threshold measuring device as described in the above embodiments;

[0026] The method for measuring the stimulated Raman scattering threshold of a multi-core optical fiber includes:

[0027] Obtaining the effective length and effective mode field area of each core of the multi-core optical fiber to be measured through the host computer;

[0028] Calculating the stimulated Raman scattering threshold of each optical fiber in the multi-core optical fiber to be measured according to the effective length and effective mode field area of each core of the multi-core optical fiber to be measured through the fitted stimulated Raman scattering threshold calculation formula;

[0029] Calculating the comprehensive stimulated Raman scattering threshold of the multi-core optical fiber to be measured according to the stimulated Raman scattering threshold of each optical fiber in the multi-core optical fiber to be measured;

[0030] Among them, the fitting process of the stimulated Raman scattering threshold calculation formula includes:

[0031] Generating an optical signal through the pump source and fan-inting the optical signal into the core of the multi-core optical fiber sample through the fan-in port;

[0032] Measuring the scattered optical signal output from each core of the multi-core optical fiber sample through the spectrometer;

[0033] Obtaining the effective length sample and effective mode field area sample of each core in the multi-core optical fiber sample through the host computer;

[0034] Determine the stimulated Raman scattering threshold sample of each core of the multi-core optical fiber sample according to the measurement result of the scattered light signal of the spectrometer;

[0035] According to the stimulated Raman scattering threshold samples, effective length samples and effective mode field area samples of all cores in the multi-core optical fiber sample, fit to obtain a calculation formula for the stimulated Raman scattering threshold.

[0036] As a preferred solution, the determining the stimulated Raman scattering threshold sample of each core of the multi-core optical fiber sample according to the measurement result of the scattered light signal of the spectrometer includes:

[0037] For each core of the multi-core optical fiber sample, according to the measurement result of the scattered light signal of the core, determine the power of the input optical signal corresponding to the non-linear sudden increase in the power of the scattered light signal, and use it as the stimulated Raman scattering threshold of the core.

[0038] As a preferred solution, the fitting to obtain a calculation formula for the stimulated Raman scattering threshold according to the stimulated Raman scattering threshold samples, effective length samples and effective mode field area samples of all cores in the multi-core optical fiber sample, with the effective length and the effective mode field area as independent variables and the stimulated Raman scattering threshold as the dependent variable, includes:

[0039] Construct a candidate formula containing several fitting parameters with the effective length and the effective mode field area as independent variables and the stimulated Raman scattering threshold as the dependent variable;

[0040] According to the stimulated Raman scattering threshold samples, effective length samples and effective mode field area samples of all cores in the multi-core optical fiber sample, fit the candidate formula to obtain the parameter values of each fitting parameter;

[0041] Generate a calculation formula for the stimulated Raman scattering threshold according to the parameter values of all fitting parameters and the candidate formula.

[0042] As a preferred solution, the candidate formula is:

[0043]

[0044] In the formula, P represents the stimulated Raman scattering threshold of the core; L represents the effective length of the core; A represents the effective mode field area of the core; g R is the Raman gain coefficient; a, b, c and d represent fitting parameters.

[0045] As a preferred solution, the calculation formula for the comprehensive stimulated Raman scattering threshold is:

[0046]

[0047] In the formula, P CTrepresents the comprehensive stimulated Raman scattering threshold; P i represents the stimulated Raman scattering threshold of the i-th core; N represents the total number of cores in the multi-core optical fiber.

[0048] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0049] The measurement device for the stimulated Raman scattering threshold of a multi-core optical fiber provided by the present invention measures and collects the scattered light signals output by each core in the multi-core optical fiber sample, and determines the stimulated Raman scattering threshold samples of each core in the multi-core optical fiber sample; according to the stimulated Raman scattering threshold samples, effective length samples, and effective mode field area samples of each core in the core optical fiber sample, a calculation formula for the stimulated Raman scattering threshold of the core is obtained by fitting; the effective length and effective mode field area of each core of the core optical fiber to be measured are obtained, and the stimulated Raman scattering threshold of each optical fiber in the multi-core optical fiber to be measured is calculated through the calculation formula for the stimulated Raman scattering threshold, and further the comprehensive stimulated Raman scattering threshold of the multi-core optical fiber to be measured is calculated. In the process of fitting the calculation formula for the stimulated Raman scattering threshold through sample data, the present invention realizes the acquisition of the stimulated Raman scattering threshold samples of each optical fiber in the multi-core optical fiber sample through a pump source, a multi-core optical fiber fan-in module, a multi-core optical fiber fan-out module, and a spectrometer. This process will inevitably involve the inter-core crosstalk effect, that is to say, this process takes into account the inter-core crosstalk effect. Therefore, the calculated formula for the stimulated Raman scattering threshold obtained by fitting is more applicable to multi-core optical fibers than the traditional measurement method for the stimulated Raman scattering threshold of a single-core optical fiber that does not involve the inter-core crosstalk effect, filling the technical gap in the calculation of the stimulated Raman scattering threshold of multi-core optical fibers. Description of the Drawings

[0050] Figure 1 is a schematic structural diagram of a measurement device for the stimulated Raman scattering threshold of a multi-core optical fiber provided by an embodiment of the present invention;

[0051] Figure 2 is a schematic flowchart of a method for measuring the stimulated Raman scattering threshold of a multi-core optical fiber provided by an embodiment of the present invention;

[0052] Among them, the reference numerals in the accompanying drawings of the specification are as follows: pump source 1, multi-core optical fiber fan-in module 2, fan-in port 21, multi-core optical fiber fan-out module 3, fan-out port 31, spectrometer 4, and host computer 5. Detailed Embodiments

[0053] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0054] Embodiment 1

[0055] Please refer to Figure 1 , which is a schematic structural diagram of a multi-core optical fiber stimulated Raman scattering threshold measurement device provided by an embodiment of the present invention, including: a pump source 1, a multi-core optical fiber fan-in module 2, a multi-core optical fiber fan-out module 3, a spectrometer 4 and a host computer 5; the multi-core optical fiber fan-in module 2 includes a plurality of fan-in ports 21; the multi-core optical fiber fan-out module 3 includes a plurality of fan-out ports 31;

[0056] Each of the fan-in ports 21 is used to connect the pump source 1 and a core of the multi-core optical fiber sample;

[0057] Each of the fan-out ports 31 is used to connect the spectrometer 4 and a core of the multi-core optical fiber sample;

[0058] The spectrometer 4 is connected to the host computer 5;

[0059] The pump source 1 is used to generate an optical signal and fan the optical signal into the core of the multi-core optical fiber sample through the fan-in port 21;

[0060] The spectrometer 4 is used to measure the scattered optical signals output from each core of the multi-core optical fiber sample;

[0061] The host computer 5 is used to obtain the effective length sample and the effective mode field area sample of each core of the multi-core optical fiber sample; determine the stimulated Raman scattering threshold sample of each core of the multi-core optical fiber sample according to the measurement result of the scattered optical signal of the spectrometer 4; fit the stimulated Raman scattering threshold calculation formula according to the stimulated Raman scattering threshold samples, effective length samples and effective mode field area samples of all cores in the multi-core optical fiber sample; and,

[0062] Obtain the effective length and effective mode field area of each core of the multi-core optical fiber to be measured; calculate the stimulated Raman scattering threshold of each optical fiber in the multi-core optical fiber to be measured through the stimulated Raman scattering threshold calculation formula according to the effective length and effective mode field area of each core of the multi-core optical fiber to be measured; calculate the comprehensive stimulated Raman scattering threshold of the multi-core optical fiber to be measured according to the stimulated Raman scattering threshold of each optical fiber in the multi-core optical fiber to be measured.

[0063] It should be noted that there are multiple cores in the multi-core optical fiber, and the effective lengths of different cores are generally the same, while the effective mode field areas may be different. The present invention obtains the effective length and effective mode field area for each core of the multi-core optical fiber to be measured.

[0064] In a preferred embodiment, determining the stimulated Raman scattering threshold sample of each core of the multi-core optical fiber sample according to the measurement result of the scattered light signal of the spectrometer 4 includes:

[0065] For each core of the multi-core optical fiber sample, according to the measurement result of the scattered light signal of the core, determine the power of the input optical signal corresponding to the non-linear sudden increase in the power of the scattered light signal as the stimulated Raman scattering threshold of the core.

[0066] In this embodiment, an input optical signal with different powers is input into the core of the multi-core optical fiber sample through the pump source 1, and at the same time, the spectrometer 4 measures the power of the scattered light signal output by the core under different input powers. The present invention uses the "slope method" to determine the stimulated Raman scattering threshold: when the scattered signal optical power shows a non-linear sudden increase with the input optical power, it is determined as the stimulated Raman scattering threshold point.

[0067] It should be noted that when measuring the stimulated Raman scattering threshold sample of the core, each core of the multi-core optical fiber sample in operation is measured, that is, there is an optical signal transmitted in all cores of the multi-core optical fiber. This is to take into account the inter-core crosstalk effect of the multi-core optical fiber, so that the stimulated Raman scattering threshold calculation formula of the present invention is more applicable to the stimulated Raman scattering threshold calculation of the multi-core optical fiber than the traditional calculation formula of the single-core optical fiber.

[0068] In another embodiment, preprocessing the sample data includes:

[0069] Filtering the sample data or removing outliers to eliminate instrument noise or accidental errors;

[0070] Taking the average value of the repeatedly measured sample data to obtain a more robust value;

[0071] Calibrating the errors of the effective length and the effective mode field area to provide a basis for uncertainty analysis for subsequent fitting.

[0072] In a preferred embodiment, fitting the stimulated Raman scattering threshold calculation formula according to the stimulated Raman scattering threshold samples, effective length samples, and effective mode field area samples of all cores in the multi-core optical fiber sample, with the effective length and the effective mode field area as independent variables and the stimulated Raman scattering threshold as the dependent variable, includes:

[0073] Construct a candidate formula containing several fitting parameters with the effective length and the effective mode field area as independent variables and the stimulated Raman scattering threshold as the dependent variable;

[0074] According to the stimulated Raman scattering threshold samples, effective length samples, and effective mode field area samples of all cores in the multi-core optical fiber sample, fit the candidate formula to obtain the parameter values of each fitting parameter;

[0075] Generate a stimulated Raman scattering threshold calculation formula according to the parameter values of all fitting parameters and the candidate formula.

[0076] In this embodiment, the fitting process of the stimulated Raman scattering threshold calculation formula is as follows: First, obtain the sample data of each core in the multi-core optical fiber sample: effective length samples, effective mode field area samples, and stimulated Raman scattering threshold samples. To ensure the reliability of the fitting results, multiple sets of data are generally obtained for each core in the experiment. For example, 20 - 30 sets of data can be collected under different conditions, covering the change range from low power to high power, and ensuring that the data has sufficient dense sampling in the key areas (such as near the threshold). Then, according to all the sample data of this core, with the effective length and effective mode field area as independent variables and the stimulated Raman scattering threshold as the dependent variable, obtain the well-fitted stimulated Raman scattering threshold calculation formula for this core through data fitting.

[0077] In a preferred embodiment, the candidate formula is:

[0078]

[0079] where P represents the stimulated Raman scattering threshold of the core; L represents the effective length of the core; A represents the effective mode field area of the core; g R is the Raman gain coefficient; a, b, c, and d represent fitting parameters.

[0080] It should be noted that the commonly used stimulated Raman scattering threshold calculation formula for single-core optical fibers is:

[0081]

[0082] where P x represents the stimulated Raman scattering threshold of the single-core optical fiber; L x represents the effective length of the single-core optical fiber; A x represents the effective mode field area of the single-core optical fiber.

[0083] For multi-core optical fibers, due to the existence of inter-core crosstalk effects, the stimulated Raman scattering threshold calculation formula for single-core optical fibers is not applicable to multi-core optical fibers. Therefore, the present invention provides a candidate formula applicable to multi-core optical fibers, fits according to the sample data, determines the parameter values of the four fitting parameters, and obtains the well-fitted stimulated Raman scattering threshold calculation formula. The well-fitted stimulated Raman scattering threshold calculation formula can directly calculate the stimulated Raman scattering threshold of the core according to the effective length and effective mode field area of the core.

[0084] The fitting method adopted in the present invention is the non - linear least - squares method. The Levenberg–Marquardt algorithm is used to estimate the parameters of the non - linear model. The specific steps include: giving an initial parameter guess value; iteratively solving until the residual converges within a preset threshold; obtaining the parameter estimation value and its confidence interval to facilitate further discussion of uncertainty and sensitivity issues. After fitting, compare the experimental data with the model prediction values, draw a residual plot, and check for systematic biases. If fitting biases are found, it may be necessary to introduce additional correction terms in the model or further screen and correct the data. After finally determining the model, the cross - validation method can be used to test the prediction performance of the model.

[0085] In a preferred embodiment, the calculation formula for the comprehensive stimulated Raman scattering threshold is as follows:

[0086]

[0087] In the formula, P CT represents the comprehensive stimulated Raman scattering threshold; P i represents the stimulated Raman scattering threshold of the i - th core; N represents the total number of cores in the multi - core optical fiber.

[0088] In this embodiment, the sum of the stimulated Raman scattering thresholds of all cores in the multi - core optical fiber to be measured is used as the comprehensive stimulated Raman scattering threshold of the multi - core optical fiber to be measured.

[0089] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. In addition, in the attached drawings of the device embodiments provided by the present invention, the connection relationship between modules indicates that they have a communication connection, which can be specifically implemented as one or more communication buses or signal lines. Those of ordinary skill in the art can understand and implement without creative efforts.

[0090] Embodiment Two

[0091] Please refer to Figure 2 , which is a schematic structural diagram of a method for measuring the stimulated Raman scattering threshold of a multi - core optical fiber provided by an embodiment of the present invention, and includes:

[0092] S1. Obtain the effective length and effective mode field area of each core of the multi - core optical fiber to be measured through the host computer 5.

[0093] S2. According to the effective length and effective mode field area of each core of the multi-core optical fiber to be measured, calculate the stimulated Raman scattering threshold of each optical fiber in the multi-core optical fiber to be measured through the well-fitted calculation formula of the stimulated Raman scattering threshold;

[0094] Among them, the fitting process of the calculation formula of the stimulated Raman scattering threshold includes:

[0095] Generate an optical signal through the pump source 1, and fan the optical signal into the core of the multi-core optical fiber sample through the fan-in port 21;

[0096] Measure the scattered optical signals output from each core of the multi-core optical fiber sample through the spectrometer 4;

[0097] Obtain the effective length sample and effective mode field area sample of each core in the multi-core optical fiber sample through the host computer 5;

[0098] Determine the stimulated Raman scattering threshold sample of each core of the multi-core optical fiber sample according to the measurement result of the scattered optical signal of the spectrometer 4;

[0099] Fit the calculation formula of the stimulated Raman scattering threshold according to the stimulated Raman scattering threshold samples, effective length samples and effective mode field area samples of all cores in the multi-core optical fiber sample.

[0100] S3. Calculate the comprehensive stimulated Raman scattering threshold of the multi-core optical fiber to be measured according to the stimulated Raman scattering threshold of each optical fiber in the multi-core optical fiber to be measured.

[0101] In a preferred embodiment, the determining the stimulated Raman scattering threshold sample of each core of the multi-core optical fiber sample according to the measurement result of the scattered optical signal of the spectrometer 4 includes:

[0102] For each core of the multi-core optical fiber sample, determine the power of the input optical signal corresponding to the non-linear sudden increase in the power of the scattered optical signal according to the measurement result of the scattered optical signal of the core, and use it as the stimulated Raman scattering threshold of the core.

[0103] In a preferred embodiment, the fitting the calculation formula of the stimulated Raman scattering threshold with the effective length and effective mode field area as independent variables and the stimulated Raman scattering threshold as the dependent variable according to the stimulated Raman scattering threshold samples, effective length samples and effective mode field area samples of all cores in the multi-core optical fiber sample includes:

[0104] Construct a candidate formula containing several fitting parameters with the effective length and effective mode field area as independent variables and the stimulated Raman scattering threshold as the dependent variable;

[0105] Fitting the candidate formula according to the stimulated Raman scattering threshold samples, effective length samples, and effective mode field area samples of all the cores in the multi-core optical fiber sample to obtain the parameter values of each fitting parameter;

[0106] Generating a stimulated Raman scattering threshold calculation formula according to the parameter values of all fitting parameters and the candidate formula.

[0107] In a preferred embodiment, the candidate formula is:

[0108]

[0109] In the formula, P represents the stimulated Raman scattering threshold of the core; L represents the effective length of the core; A represents the effective mode field area of the core; g R is the Raman gain coefficient; a, b, c, and d represent fitting parameters.

[0110] In a preferred embodiment, the calculation formula of the comprehensive stimulated Raman scattering threshold is:

[0111]

[0112] In the formula, P CT represents the comprehensive stimulated Raman scattering threshold; P i represents the stimulated Raman scattering threshold of the i-th core; N represents the total number of cores in the multi-core optical fiber.

[0113] Those skilled in the art can clearly understand that for the sake of convenience and brevity, the specific process of the method described above can refer to the corresponding process in the foregoing device embodiment, which will not be elaborated here.

[0114] The above specific embodiments have further elaborated on the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. In particular, it is pointed out that for those skilled in the art, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A measuring device for the stimulated Raman scattering threshold of a multi-core optical fiber, characterized in that Including: A pump source, a multi-core fiber fan-in module, a multi-core fiber fan-out module, a spectrometer, and a host computer; the multi-core fiber fan-in module includes a plurality of fan-in ports; the multi-core fiber fan-out module includes a plurality of fan-out ports; Each of the fan-in ports is used to connect the pump source and one core of the multi-core fiber sample; Each of the fan-out ports is used to connect the spectrometer and one core of the multi-core fiber sample; The spectrometer is connected to the host computer; The pump source is used to generate an optical signal and fan the optical signal into the core of the multi-core fiber sample through the fan-in port; The spectrometer is used to measure the scattered optical signals output from each core of the multi-core fiber sample; The host computer is used to obtain the effective length sample and the effective mode field area sample of each core in the multi-core fiber sample; according to the measurement result of the scattered optical signal of the spectrometer, determine the stimulated Raman scattering threshold sample of each core of the multi-core fiber sample; According to the stimulated Raman scattering threshold samples, effective length samples, and effective mode field area samples of all cores in the multi-core fiber sample, fit to obtain a stimulated Raman scattering threshold calculation formula; And, Obtain the effective length and effective mode field area of each core of the multi-core fiber to be measured; According to the effective length and effective mode field area of each core of the multi-core fiber to be measured, through the stimulated Raman scattering threshold calculation formula, calculate the stimulated Raman scattering threshold of each fiber in the multi-core fiber to be measured; According to the stimulated Raman scattering threshold of each fiber in the multi-core fiber to be measured, calculate the comprehensive stimulated Raman scattering threshold of the multi-core fiber to be measured.

2. The stimulated Raman scattering threshold measurement device for multi-core optical fiber according to claim 1, characterized in that, The determining the stimulated Raman scattering threshold sample of each core of the multi-core fiber sample according to the measurement result of the scattered optical signal of the spectrometer includes: For each core of the multi-core fiber sample, according to the measurement result of the scattered optical signal of the core, determine the power of the input optical signal corresponding to the non-linear sudden increase in the power of the scattered optical signal as the stimulated Raman scattering threshold of the core.

3. The stimulated Raman scattering threshold measurement device for multi-core optical fiber according to claim 1, characterized in that, The fitting to obtain the stimulated Raman scattering threshold calculation formula with the effective length and effective mode field area as independent variables and the stimulated Raman scattering threshold as the dependent variable according to the stimulated Raman scattering threshold samples, effective length samples, and effective mode field area samples of all cores in the multi-core fiber sample includes: Construct a candidate formula containing several fitting parameters with the effective length and effective mode field area as independent variables and the stimulated Raman scattering threshold as the dependent variable; According to the stimulated Raman scattering threshold samples, effective length samples, and effective mode field area samples of all cores in the multi-core fiber sample, fit the candidate formula to obtain the parameter values of each fitting parameter; According to the parameter values of all fitting parameters and the candidate formula, generate a stimulated Raman scattering threshold calculation formula.

4. The stimulated Raman scattering threshold measurement device for multi-core optical fiber according to claim 3, wherein, The candidate formula is: Wherein, P represents the stimulated Raman scattering threshold of the core; L represents the effective length of the core; A represents the effective mode field area of the core; g R is the Raman gain coefficient; a, b, c, and d represent fitting parameters.

5. The stimulated Raman scattering threshold measurement device for multi-core optical fiber according to claim 1, characterized in that The calculation formula of the comprehensive stimulated Raman scattering threshold is: where P CT represents the stimulated Raman scattering threshold of the integrated Raman amplifier; P i represents the stimulated Raman scattering threshold of the i-th core; N represents the total number of cores in the multi-core fiber.

6. A method for measuring the stimulated Raman scattering threshold of a multi-core optical fiber, characterized in that, Applicable to the multi-core fiber stimulated Raman scattering threshold measurement device according to any one of claims 1 to 5; The multi-core fiber stimulated Raman scattering threshold measurement method includes: Obtain the effective length and effective mode field area of each core of the multi-core optical fiber to be measured through the host computer; According to the effective length and effective mode field area of each core of the multi-core optical fiber to be measured, calculate the stimulated Raman scattering threshold of each optical fiber in the multi-core optical fiber to be measured through the fitted stimulated Raman scattering threshold calculation formula; Calculate the comprehensive stimulated Raman scattering threshold of the multi-core optical fiber to be measured according to the stimulated Raman scattering threshold of each optical fiber in the multi-core optical fiber to be measured; Among them, the fitting process of the stimulated Raman scattering threshold calculation formula includes: Generate an optical signal through the pump source and fan the optical signal into the core of the multi-core optical fiber sample through the fan-in port; Measure the scattered optical signal output from each core of the multi-core optical fiber sample through the spectrometer; Obtain the effective length sample and effective mode field area sample of each core of the multi-core optical fiber sample through the host computer; Determine the stimulated Raman scattering threshold sample of each core of the multi-core optical fiber sample according to the measurement result of the scattered optical signal of the spectrometer; Fit the stimulated Raman scattering threshold calculation formula according to the stimulated Raman scattering threshold samples, effective length samples and effective mode field area samples of all cores in the multi-core optical fiber sample; 7. The method for measuring the stimulated Raman scattering threshold of a multi-core optical fiber according to claim 6, characterized in that, The determining the stimulated Raman scattering threshold sample of each core of the multi-core optical fiber sample according to the measurement result of the scattered optical signal of the spectrometer includes: For each core of the multi-core optical fiber sample, determine the power of the input optical signal corresponding to the non-linear sudden increase in the power of the scattered optical signal according to the measurement result of the scattered optical signal of the core, as the stimulated Raman scattering threshold of the core; 8. The method for measuring the stimulated Raman scattering threshold of a multi-core optical fiber according to claim 6, characterized in that The fitting the stimulated Raman scattering threshold calculation formula with the effective length and effective mode field area as independent variables and the stimulated Raman scattering threshold as the dependent variable according to the stimulated Raman scattering threshold samples, effective length samples and effective mode field area samples of all cores in the multi-core optical fiber sample includes: Construct a candidate formula containing several fitting parameters with the effective length and effective mode field area as independent variables and the stimulated Raman scattering threshold as the dependent variable; Fit the candidate formula according to the stimulated Raman scattering threshold samples, effective length samples and effective mode field area samples of all cores in the multi-core optical fiber sample to obtain the parameter values of each fitting parameter; Generate the stimulated Raman scattering threshold calculation formula according to the parameter values of all fitting parameters and the candidate formula; 9. The method for measuring the stimulated Raman scattering threshold of a multi-core optical fiber according to claim 8, wherein The candidate formula is: Wherein, P represents the stimulated Raman scattering threshold of the core; L represents the effective length of the core; A represents the effective mode field area of the core; g R is the Raman gain coefficient; a, b, c, and d represent fitting parameters.

10. The method for measuring the stimulated Raman scattering threshold of a multi-core optical fiber according to claim 6, characterized in that, The calculation formula of the comprehensive stimulated Raman scattering threshold is: Wherein, P CT represents the comprehensive stimulated Raman scattering threshold; P i represents the stimulated Raman scattering threshold of the i-th core; N represents the total number of cores in the multi-core optical fiber.

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