A multi-channel comprehensive test device and method for Erbium-Ytterbium co-doped high-power optical fiber amplifier

Abstract

The present application relates to the field of fiber amplifier integrated testing technology, and specifically to a multi-channel integrated testing device and method for erbium-ytterbium co-doped high-power fiber amplifiers. The method comprises: analyzing the discrete degree and average distribution of pump power at all moments within a preset time period after each characteristic moment, measuring the fluctuation degree and average level of input optical power at all moments within a preset time period after each characteristic moment, combining the difference in the optical spectrum between the optical pulse signal and the output signal at each characteristic moment, and performing weighted fitting on the output optical power and gain to perform a multi-channel integrated test on the current channel of the fiber amplifier under test at the current moment. The present application solves the problem of the instability of the pump light source and signal light in the time domain, as well as the interference of spontaneous radiation amplification noise on the saturated output optical power test, thereby improving the accuracy of the integrated test results of pulsed erbium-ytterbium co-doped high-power fiber amplifiers.

Description

Technical Field

[0001] The present application relates to the technical field of integrated testing of optical fiber amplifiers, and in particular to a multi-channel integrated testing device and method for erbium-ytterbium co-doped high-power optical fiber amplifiers. Background Art

[0002] Erbium-ytterbium co-doped high-power fiber amplifiers are high-performance fiber amplifiers that utilize optical fibers co-doped with erbium and ytterbium ions as the gain medium. They offer the advantages of high power output and low cost. As core components for signal transmission in fiber-optic communication systems, fiber amplifier performance directly impacts the stability and transmission efficiency of the entire network. Multi-channel integrated testing, which enables simultaneous testing of multiple signals within a fiber amplifier's multiple channels, provides a more comprehensive assessment of the amplifier's overall performance in multi-signal processing scenarios, providing strong support for amplifier optimization.

[0003] Existing fiber amplifier performance tests typically examine various performance parameters, including saturated output optical power, power conversion efficiency, and quantum conversion efficiency. The saturated output optical power reflects the maximum optical power that a fiber amplifier can output when in a gain saturation state and is a key parameter for evaluating its amplification performance. Existing methods typically obtain the saturated output optical power by establishing a relationship curve between the gain of a fiber amplifier and its output optical power. However, when testing pulsed erbium-ytterbium co-doped high-power fiber amplifiers, the instability of the pump light source and signal light in the time domain, as well as interference from spontaneous emission amplification noise, can lead to certain deviations in measuring the signal light output power and calculating the gain of the fiber amplifier. This makes it difficult to accurately obtain the saturated output optical power test results of the fiber amplifier, thereby reducing the accuracy of the comprehensive test results of pulsed erbium-ytterbium co-doped high-power fiber amplifiers. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide an Erbium-Ytterbium co-doped high-power fiber amplifier multi-channel comprehensive testing device and method. The technical solutions adopted are as follows:

[0005] In a first aspect, an embodiment of the present application provides a multi-channel comprehensive testing method for an erbium-ytterbium co-doped high-power fiber amplifier, the method comprising the following steps:

[0006] An optical pulse signal is emitted to the current channel of the optical fiber amplifier under test, and the input optical power, output optical power, and pump power of the optical fiber amplifier under test are obtained in real time. The moment when the input optical power reaches the preset target power is recorded as the characteristic moment; the optical spectrum of the optical pulse signal and the output signal at each characteristic moment is obtained respectively; and the wavelength of the optical pulse signal and the pump light source are obtained respectively;

[0007] The first confidence level of the input optical power at each characteristic moment is determined by analyzing the dispersion and average distribution of the pump power at all moments within a preset time period after each characteristic moment; the second confidence level of the input optical power at each characteristic moment is determined by measuring the fluctuation and average level of the input optical power at all moments within a preset time period after each characteristic moment; and the third confidence level of the input optical power at each characteristic moment is determined by comparing the difference in the optical spectrum between the optical pulse signal and the output signal at each characteristic moment.

[0008] Based on the first confidence level, the second confidence level, and the third confidence level, determining a comprehensive confidence level of the input optical power at each characteristic moment; recording the ratio of the output optical power to the input optical power at each moment as the gain, and based on the comprehensive confidence level, performing a weighted fitting of the output optical power and gain at the characteristic moments corresponding to all different preset target powers closest to the current moment before the current moment;

[0009] Based on the fitting curve, the difference between the average level of gain and the average level of all pump powers at all times in the preset period before the current moment, and the difference between the wavelength of the optical pulse signal and the wavelength of the pump light source, a multi-channel comprehensive test is performed on the current channel of the optical fiber amplifier under test at the current moment.

[0010] Preferably, the preset target power includes: -5dBm, -3.5dBm, -2dBm, -0.5dBm, 1dBm, 2.5dBm, 4dBm, 5.5dBm, 7dBm, 8.5dBm, and 10dBm.

[0011] Preferably, the method for determining the first confidence level of the input optical power at each characteristic moment is:

[0012] The standard deviation and mean of the pump power at all moments within a preset time period after each characteristic moment are calculated, and the reciprocal of the product of the normalized value of the standard deviation and the normalized value of the reciprocal of the mean is taken as the first confidence level of the input optical power at each characteristic moment.

[0013] Preferably, the method for determining the second confidence level of the input optical power at each characteristic moment is:

[0014] Calculate the standard deviation and mean of the input optical power at all moments within a preset time period after each characteristic moment, and record them as the first eigenvalue and the second eigenvalue respectively. Take the reciprocal of the product of the normalized value of the first eigenvalue and the normalized value of the reciprocal of the second eigenvalue as the second confidence level of the input optical power at each characteristic moment.

[0015] Preferably, the method for determining the interference characteristic value of the input optical power at each characteristic moment is:

[0016] Spectra within a preset wavelength range are extracted from the spectrum diagram of the optical pulse signal at each characteristic moment, and are recorded as a first spectrum and a second spectrum, respectively. The mean of the spectral intensity at all wavelengths other than the wavelength corresponding to the optical pulse signal in the first spectrum and the mean of the spectral intensity at all wavelengths other than the wavelength corresponding to the optical pulse signal in the second spectrum are calculated, and are recorded as a first mean value and a second mean value, respectively. The difference between the second mean value and the first mean value is divided by the first mean value, and the result is used as the interference characteristic value of the input optical power at each characteristic moment.

[0017] Preferably, the third confidence level of the input optical power at each characteristic moment is the inverse of a normalized value of an interference characteristic value of the input optical power at each characteristic moment.

[0018] Preferably, the comprehensive confidence of the input optical power at each characteristic moment is the product of the normalized value of the first confidence, the normalized value of the second confidence and the normalized value of the third confidence of the input optical power at each characteristic moment.

[0019] Preferably, performing weighted fitting on the output optical power and gain at characteristic moments corresponding to all different preset target powers closest to the current moment before the current moment includes:

[0020] The output optical power and gain at each characteristic moment are combined into a binary group, and all binary groups corresponding to the characteristic moments of all different preset target powers closest to the current moment before the current moment are used as inputs based on the weighted fitting algorithm, wherein the normalized value of the comprehensive confidence of the input optical power at the corresponding characteristic moment is used as the weight of the binary group, and the fitting curve is output.

[0021] Preferably, the performing of a multi-channel comprehensive test on the current channel of the optical fiber amplifier to be tested at the current moment includes:

[0022] The saturated output optical power of the optical fiber amplifier under test at the current moment is calculated based on the fitting curve, and is used as the saturated output optical power test result of the current channel of the optical fiber amplifier under test at the current moment;

[0023] Calculate the gain average at all times in a preset period before the current moment divided by the pump power average at all times as the power conversion efficiency test result of the current channel of the optical fiber amplifier under test at the current moment;

[0024] The ratio of the wavelength of the optical pulse signal to the wavelength of the pump light source is calculated, and the product of the ratio and the power conversion efficiency test result is used as the quantum conversion efficiency test result of the current channel of the optical fiber amplifier to be tested at the current moment.

[0025] In a second aspect, an embodiment of the present application further provides an erbium-ytterbium co-doped high-power fiber amplifier multi-channel integrated testing device, comprising a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of any one of the above-mentioned erbium-ytterbium co-doped high-power fiber amplifier multi-channel integrated testing methods are implemented.

[0026] This application has at least the following beneficial effects:

[0027] The present application determines first, second, and third confidence levels for the input optical power by analyzing the dispersion and average distribution of the pump power, the fluctuation and average level of the input optical power, and the spectral characteristics of the output signal. A comprehensive confidence level is constructed based on the obtained first, second, and third confidence levels. This allows for a more accurate assessment of the degree to which the measurement results of different output optical powers of the optical fiber amplifier under test, as well as the gains calculated from the measurement results, approach their respective actual results when measuring the output optical power of the optical fiber amplifier under test. This allows for a more accurate establishment of a relationship curve between the gain of the optical fiber amplifier and its output optical power. Furthermore, the present application utilizes a weighted fitting algorithm to perform data fitting on the output optical power and gain of the optical fiber amplifier under test. The weights corresponding to the output optical powers and gains of the comprehensive confidence levels are assigned in the fitting algorithm. This allows the fitting curve to more closely follow the output optical powers and gains of the optical fiber amplifiers with higher confidence levels, more accurately reflecting the relationship between the gain and output optical power of the optical fiber amplifier under test. This allows for more accurate detection of the saturated output optical power of the optical fiber amplifier, thereby improving the accuracy of the comprehensive test results of pulsed erbium-ytterbium co-doped high-power optical fiber amplifiers. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present application or the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0029] Figure 1 A flowchart of a multi-channel comprehensive testing method for an erbium-ytterbium co-doped high-power fiber amplifier provided in one embodiment of the present application;

[0030] Figure 2 A schematic diagram of the comprehensive confidence extraction process provided for one embodiment of the present application. DETAILED DESCRIPTION

[0031] To further illustrate the technical means and effectiveness of this application's objectives, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effectiveness of the Er / Yb co-doped high-power fiber amplifier multi-channel integrated testing device and method proposed in this application. In the following description, references to "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0032] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0033] The specific scheme of the multi-channel comprehensive testing device and method for erbium-ytterbium co-doped high-power optical fiber amplifier provided by the present application is described in detail below with reference to the accompanying drawings.

[0034] See also Figure 1 , which shows a flowchart of a multi-channel comprehensive testing method for an erbium-ytterbium co-doped high-power fiber amplifier provided by an embodiment of the present application, the method comprising the following steps:

[0035] Step S1: An optical pulse signal is emitted to the current channel of the optical fiber amplifier under test, and the input optical power, output optical power, and pump power of the optical fiber amplifier under test are obtained in real time. The moment when the input optical power reaches a preset target power is recorded as a characteristic moment; the optical spectrum of the optical pulse signal and the output signal at each characteristic moment is obtained respectively; and the wavelength of the optical pulse signal and the pump light source are obtained respectively.

[0036] An optical pulse signal generated by a pulsed laser is used as the input signal of the current channel in the optical fiber amplifier under test. In this embodiment, the wavelength, repetition rate, pulse width, and pulse peak power of the optical pulse signal are 1550 nm, 100 kHz, 50 ns, and 10 W, respectively. The wavelength, repetition rate, pulse width, and pulse peak value of the optical pulse signal are manually set. In actual application, as other implementation methods, implementers can also set them according to specific circumstances. This embodiment does not impose any special restrictions. The wavelength must be within the operating band of the optical fiber amplifier under test.

[0037] In this embodiment, an optical power meter is used to obtain the input optical power and output optical power of the optical fiber amplifier under test in real time, and a pump power monitoring system is used to synchronously and in real time obtain the pump power of the optical fiber amplifier under test. The data acquisition frequency is set to f, and multiple different input optical powers are selected for the optical fiber amplifier under test. In this embodiment, the moment when the input optical power reaches a preset target power is recorded as a characteristic moment. The input optical power range of the optical fiber amplifier under test is from -5 dBm to 10 dBm. In this embodiment, the preset input optical powers are -5 dBm, -3.5 dBm, -2 dBm, -0.5 dBm, 1 dBm, 2.5 dBm, 4 dBm, 5.5 dBm, 7 dBm, 8.5 dBm, and 10 dBm, respectively. The value of the input optical power is manually set. In actual application, as other implementation methods, implementers can also set it according to specific circumstances. This embodiment does not impose any special restrictions.

[0038] It should be noted that the value of the data acquisition frequency f is set manually. In this embodiment, the value of the data acquisition frequency f is 100kHz. In actual application, as other implementation methods, the implementer can also set it by himself according to the specific situation. This embodiment does not impose any special restrictions.

[0039] Furthermore, a spectrum analyzer is used to obtain the optical pulse signal and the spectrum of the output signal of the optical fiber amplifier to be tested at each characteristic moment; further, the wavelengths of the optical pulse signal and the pump light source are obtained respectively.

[0040] The pump power monitoring system is a well-known technology, and the specific process of using the pump power monitoring system to synchronously and real-time obtain the pump power of the optical fiber amplifier to be tested will not be described in detail.

[0041] Step S2: Determine a first confidence level of the input optical power at each characteristic moment by analyzing the degree of dispersion and average distribution of the pump power at all moments within a preset time length after each characteristic moment; measure the degree of fluctuation and average level of the input optical power at all moments within a preset time length after each characteristic moment to determine a second confidence level of the input optical power at each characteristic moment; compare the difference in the optical spectrum between the optical pulse signal and the output signal at each characteristic moment to determine the interference characteristic value of the input optical power at each characteristic moment, so as to determine a third confidence level of the input optical power at each characteristic moment.

[0042] Generally, when using a pulsed fiber amplifier to amplify optical pulse signals, the pump light, input optical signal, and spontaneous emission noise in the pulsed fiber amplifier are all time-dependent quantities. As the pump power of the fiber amplifier under test increases, more and more low-energy erbium ion electrons in the fiber of the fiber amplifier under test absorb the high energy of the pump light and transition to high energy levels, thereby increasing the output optical power of the fiber amplifier under test. However, as the pump power increases, the gain of the fiber amplifier under test is increasingly less affected by the pump power, and gradually becomes saturated. Therefore, when measuring the output optical power corresponding to each input optical power of the fiber amplifier under test, the more stable and larger the pump power variation of the fiber amplifier under test, the closer the gain calculated based on the measured output optical power and the corresponding input optical power is to its true value.

[0043] Therefore, based on the above analysis, this embodiment determines the first confidence level of the input optical power at each characteristic moment by analyzing the dispersion and average distribution of the pump power at all moments within a preset time period after each characteristic moment. Specifically, it is:

[0044] In this embodiment, the standard deviation and mean of the pump power at all moments within a preset time period after each characteristic moment are calculated. The reciprocal of the product of the normalized value of the standard deviation and the normalized value of the reciprocal of the mean is taken as the first confidence level of the input optical power at each characteristic moment. This is used to evaluate the degree of fluctuation in the pump power of the optical fiber amplifier under test and the degree of its impact on the gain of the optical fiber amplifier under test at the input optical power corresponding to the characteristic moment.

[0045] It should be noted that the value of the preset duration is set manually. In this embodiment, the value of the preset duration is the length between two adjacent characteristic moments. In actual application, as other implementation methods, the implementer can also set it by himself based on the specific situation. This embodiment does not impose any special restrictions.

[0046] It should be noted that there are many commonly used normalization methods. In this embodiment, all contents involving normalization and calculation adopt the maximum and minimum value normalization method. In actual application, as other implementation methods, implementers can also adopt other normalization methods such as z-score normalization method based on specific circumstances. Regarding the selection of normalization method, this embodiment does not impose any special restrictions.

[0047] Among them, the maximum and minimum value normalization method is a well-known technology, and the specific process of normalizing and calculating the data will not be described in detail.

[0048] According to the first confidence level of the input optical power at each characteristic moment, it can be understood that the smaller the standard deviation of the pump power within the preset time length after the current characteristic moment, the smaller the fluctuation of the pump power, indicating that the change of the pump power is more stable when measuring the output optical power. Therefore, the first confidence level of the corresponding input optical power at the current characteristic moment is greater. At the same time, if the mean value of the pump power within the preset time length after the current characteristic moment is greater, it means that the gain calculated from the measured output optical power and the corresponding input optical power is closer to its true value. Therefore, the first confidence level of the input power at the current characteristic moment is greater.

[0049] On the contrary, the larger the standard deviation of the pump power within the preset time length after the current characteristic moment, the greater the fluctuation of the pump power, indicating that the change of the pump power is more unstable when measuring the output optical power. Therefore, the first confidence level of the corresponding input optical power at the current characteristic moment is smaller. At the same time, if the mean value of the pump power within the preset time length after the current characteristic moment is smaller, it means that the gain calculated from the measured output optical power and the corresponding input optical power deviates more from its true value. Therefore, the first confidence level of the input power at the current characteristic moment is smaller.

[0050] When measuring the output power of a fiber optic amplifier, the more stable the change in the input optical power of the fiber optic amplifier, the closer the measured output optical power result is generally to the true value. In addition, the output power of a fiber optic amplifier generally increases with the increase in its input optical power. However, as the input optical power increases, the rate of increase in the output optical power gradually slows down and then approaches a saturation state. Therefore, when measuring the output optical power corresponding to each input optical power of the fiber optic amplifier under test, the more stable and larger the change in the input optical power of the fiber optic amplifier under test, the closer the measured output optical power value is to its true value.

[0051] Therefore, based on the above analysis, this embodiment determines the second confidence level of the input optical power at each characteristic moment by measuring the fluctuation degree and average level of the input optical power at all moments within a preset time period after each characteristic moment, specifically:

[0052] As an implementation method, in this embodiment, the standard deviation and mean of the input optical power at all moments within a preset time period after each characteristic moment are calculated, and are recorded as the first eigenvalue and the second eigenvalue, respectively. The reciprocal of the result of multiplying the normalized value of the first eigenvalue by the normalized value of the reciprocal of the second eigenvalue is taken as the second confidence level of the input optical power at each characteristic moment.

[0053] According to the second confidence level of the input optical power at each characteristic moment, it can be understood that the smaller the standard deviation of the input optical power within the preset time length after the current characteristic moment, the smaller the fluctuation of the input optical power, indicating that when measuring the output optical power, the change of the input optical power is more stable. Therefore, the second confidence level of the corresponding input optical power at the current characteristic moment is greater; at the same time, if the mean value of the input optical power within the preset time length after the current characteristic moment is greater, it means that the gain calculated from the measured output optical power and the corresponding input optical power is closer to its true value. Therefore, the second confidence level of the input power at the current characteristic moment is greater;

[0054] On the contrary, the larger the standard deviation of the input optical power within the preset time length after the current characteristic moment, the greater the fluctuation of the input optical power, which indicates that the change of the input optical power is more unstable when measuring the output optical power. Therefore, the second confidence level of the corresponding input optical power at the current characteristic moment is smaller; at the same time, if the mean value of the input optical power within the preset time length after the current characteristic moment is smaller, it means that the gain calculated from the measured output optical power and the corresponding input optical power deviates more from its true value. Therefore, the second confidence level of the input power at the current characteristic moment is smaller.

[0055] Furthermore, during the process of amplifying the input optical signal using the optical fiber amplifier under test, some erbium ions in the upper energy level of the laser will spontaneously transition to the ground state and randomly emit photons without stimulated radiation, generating light of all wavelengths within a wavelength range. These lights will also be amplified during transmission, thereby generating spontaneous emission amplification noise covering the entire operating wavelength band of the optical fiber amplifier under test. The spontaneous emission amplification noise will be output at the output end of the optical fiber simultaneously with the amplified signal light, so that the actually measured output optical power will usually include the power of the spontaneous emission amplification noise, thereby deviating from the actual optical signal output power.

[0056] The operating bands of erbium-ytterbium co-doped fiber amplifiers generally include the C-band (1530-1565 nm) and the L-band (1565-1625 nm). Therefore, spectra within preset wavelength ranges are extracted from the spectrum of the optical pulse signal at each characteristic moment, respectively recorded as a first spectrum and a second spectrum. The mean values ​​of the spectral intensities at all wavelengths other than the wavelength corresponding to the optical pulse signal in the first spectrum and the mean values ​​of the spectral intensities at all wavelengths other than the wavelength corresponding to the optical pulse signal in the second spectrum are calculated, respectively recorded as a first mean value and a second mean value. The difference between the second mean value and the first mean value is divided by the first mean value to obtain the result of the interference characteristic value of the input optical power at each characteristic moment.

[0057] The value of the preset wavelength range is manually set. In this embodiment, the value of the preset wavelength range is 1530 nm-1625 nm.

[0058] According to the interference characteristic values ​​of the input optical power at each characteristic moment, it can be understood that the first mean value is used to evaluate the spectral intensity corresponding to the background noise of the input optical signal of the optical fiber amplifier under test before amplification, and the second mean value is used to evaluate the spectral intensity corresponding to the background noise of the input signal of the optical fiber amplifier under test after amplification. The greater the difference between the second mean value and the first mean value compared with the first mean value, the larger the corresponding interference characteristic value, indicating that at the input optical power corresponding to the current characteristic moment, the degree of interference of the output optical signal of the optical fiber amplifier under test by the spontaneous emission amplification noise is greater, indicating that the influence of the spontaneous emission amplification noise is more serious, indicating that at the input optical power corresponding to the current characteristic moment, the measured output optical power deviates more from the actual optical signal output power of the optical fiber amplifier under test;

[0059] On the contrary, the smaller the difference between the second mean and the first mean is compared with the first mean, the smaller the corresponding interference characteristic value is, indicating that at the input optical power corresponding to the current characteristic moment, the degree to which the output optical signal of the optical fiber amplifier under test is interfered with by the spontaneous radiation amplification noise is smaller, indicating that the influence of the spontaneous radiation amplification noise is smaller, indicating that at the input optical power corresponding to the current characteristic moment, the degree to which the measured output optical power deviates from the actual optical signal output power of the optical fiber amplifier under test is smaller.

[0060] Furthermore, in this embodiment, the inverse of the normalized value of the interference characteristic value of the input optical power at each characteristic moment is used as the third confidence level of the input optical power at each characteristic moment based on the interference characteristic value, wherein a larger third confidence level indicates a smaller impact of the spontaneous emission amplification noise on the emitted radiation amplification noise, indicating that at the input optical power corresponding to the current characteristic moment, the measured output optical power deviates less from the actual optical signal output power of the optical fiber amplifier under test.

[0061] Thus, this embodiment determines the first, second, and third confidence levels for the input optical power by analyzing the dispersion and average distribution of the pump power, the fluctuation and average level of the input optical power, and the spectral characteristics of the output signal. The first confidence level reflects the impact of pump power stability on gain, the second confidence level reflects the impact of input optical power stability on the authenticity of the output optical power, and the third confidence level reflects the degree of interference of spontaneous emission noise on the output optical power measurement. Combining these three confidence levels can more accurately evaluate the performance of fiber amplifiers at different input optical powers, improving the reliability, accuracy, and signal quality of measurement results.

[0062] Step S3: Based on the first confidence level, the second confidence level, and the third confidence level, determine the comprehensive confidence level of the input optical power at each characteristic moment; record the ratio of the output optical power to the input optical power at each moment as the gain, and based on the comprehensive confidence level, perform weighted fitting on the output optical power and gain at the characteristic moment corresponding to all different preset target powers closest to the current moment before the current moment. Based on the analysis and calculation of step S2, the first confidence level, the second confidence level, and the third confidence level are obtained. Therefore, this embodiment further determines the comprehensive confidence level of the input optical power at each characteristic moment based on the first confidence level, the second confidence level, and the third confidence level, specifically:

[0063] As an implementation method, in this embodiment, the product of the normalized value of the first confidence level of the input optical power at each characteristic moment, the normalized value of the second confidence level, and the normalized value of the third confidence level is used as the comprehensive confidence level of the input optical power at each characteristic moment.

[0064] Preferably, the schematic diagram of the comprehensive confidence extraction process provided in this embodiment is as follows Figure 2 shown.

[0065] According to the comprehensive confidence of the input optical power at each characteristic moment, it can be understood that the comprehensive confidence reflects the reliability, accuracy and signal quality of the output optical power measurement results. The larger the first confidence, the more stable the pump power, and the less the output optical power measurement results are affected by pump power fluctuations. Therefore, the higher the reliability of the measurement results, the higher the comprehensive confidence. The larger the second confidence, the closer the gain calculated based on the input and output optical powers is to the true value, and the higher the accuracy of the measurement results. Therefore, the higher the comprehensive confidence. At the same time, the larger the third confidence, the less the output signal is affected by the spontaneous radiation amplification noise, the higher the signal quality, and the smaller the deviation of the measured output optical power from the actual optical signal output power of the fiber amplifier under test. Therefore, the comprehensive confidence is also higher.

[0066] On the contrary, the smaller the first confidence level, the more unstable the pump power is, and the greater the impact of pump power fluctuations on the output optical power measurement result is. Therefore, the reliability of the measurement result is lower, and the overall confidence level is lower. The smaller the second confidence level, the more the gain calculated based on the input and output optical powers deviates from the true value, and the lower the accuracy of the measurement result is. Therefore, the overall confidence level is also lower. At the same time, the smaller the third confidence level, the greater the degree of interference of the output signal by spontaneous emission amplification noise, the lower the signal quality, and the greater the degree to which the measured output optical power deviates from the actual optical signal output power of the fiber amplifier under test. Therefore, the overall confidence level is also lower.

[0067] Furthermore, this embodiment performs weighted fitting on the output optical power and gain at the characteristic moments corresponding to all different preset target powers closest to the current moment based on the comprehensive confidence, specifically:

[0068] In this embodiment, the ratio of the output optical power to the input optical power at each moment is recorded as the gain at each moment, the output optical power and the gain at each characteristic moment are combined into a binary group, and all binary groups corresponding to the characteristic moments of all different preset target powers closest to the current moment before the current moment are used as inputs based on the weighted fitting algorithm, wherein the normalized value of the comprehensive confidence of the input optical power at the corresponding characteristic moment is used as the weight of the binary group, and the fitting curve is output.

[0069] It should be noted that, during the fitting process, the output optical power is the independent variable and the gain is the dependent variable.

[0070] In addition, it should be noted that if there is no characteristic moment before the current moment, it means that the output optical power has not yet reached saturation. Therefore, this moment is not considered and curve fitting is not performed.

[0071] It should be noted that there are many commonly used fitting methods. In this embodiment, a weighted least squares fitting method is used to perform weighted fitting on the binary group. In actual application, the implementer may also adopt other weighted fitting algorithms based on specific circumstances. Regarding the selection of the fitting method, this embodiment does not impose any special restrictions.

[0072] The weighted least squares fitting method is a well-known technique, and the specific process of fitting the binary group using the method will not be described in detail.

[0073] Thus, this embodiment constructs a comprehensive confidence level by integrating the first, second, and third confidence levels of the input optical power at each characteristic moment. Based on the comprehensive confidence level, a weighted fitting is performed on the output optical power and gain of the optical fiber amplifier. Through weighted fitting, a more accurate relationship curve between the output optical power and gain can be obtained, which helps to evaluate the performance of the optical fiber amplifier.

[0074] Step S4: Based on the fitting curve, the difference between the average level of gain and the average level of all pump powers at all times in a preset period before the current moment, and the difference between the wavelength of the optical pulse signal and the wavelength of the pump light source, a multi-channel comprehensive test is performed on the current channel of the optical fiber amplifier to be tested at the current moment.

[0075] Based on the fitting curve obtained by analysis in step S3, this embodiment further performs a multi-channel comprehensive test on the current channel of the optical fiber amplifier under test at the current moment based on the fitting curve, the difference between the average level of gain and the average level of all pump powers at all moments in a preset period before the current moment, and the difference between the wavelength of the optical pulse signal and the wavelength of the pump light source. Specifically,

[0076] The saturated output optical power of the optical fiber amplifier under test at the current moment is calculated based on the fitting curve, and is used as the saturated output optical power test result of the current channel of the optical fiber amplifier under test at the current moment;

[0077] Further, the gain average at all moments in a preset time period before the current moment is divided by the pump power average at all moments, and the result is used as the power conversion efficiency test result of the current channel of the optical fiber amplifier under test at the current moment;

[0078] Furthermore, the ratio of the wavelength of the optical pulse signal to the wavelength of the pump light source is calculated, and the product of the ratio and the power conversion efficiency test result is used as the quantum conversion efficiency test result of the current channel of the optical fiber amplifier to be tested at the current moment.

[0079] The calculation of the saturated output optical power of the optical fiber amplifier to be tested at the current moment based on the fitting curve is a well-known technique, and the specific calculation process of the saturated output optical power will not be described in detail.

[0080] Thus, this embodiment determines the first, second, and third confidence levels of the input optical power by analyzing the dispersion of the pump power, the fluctuation of the input optical power, and the spectral characteristics of the output signal. Combining these three confidence levels can more accurately evaluate the performance of the fiber amplifier at different input optical powers. Based on the combined confidence levels, a weighted fit of the output optical power and gain can be performed to obtain a more accurate relationship curve between the output optical power and gain, which helps to evaluate the saturated output optical power, power conversion efficiency, and quantum conversion efficiency of the fiber amplifier.

[0081] Based on the same inventive concept as the above-mentioned method, an embodiment of the present application further provides an erbium-ytterbium co-doped high-power fiber amplifier multi-channel integrated testing device, comprising a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of any one of the above-mentioned erbium-ytterbium co-doped high-power fiber amplifier multi-channel integrated testing methods are implemented.

[0082] It should be noted that the order in which the embodiments of the present application are presented is for illustrative purposes only and does not necessarily represent the superiority or inferiority of the embodiments. Furthermore, the foregoing descriptions of specific embodiments of this specification are provided. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order or sequential sequence shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0083] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0084] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A multi-channel comprehensive testing method for Erbium-Ytterbium co-doped high-power fiber amplifier, characterized in that: The method comprises the following steps: An optical pulse signal is emitted to the current channel of the optical fiber amplifier under test, and the input optical power, output optical power, and pump power of the optical fiber amplifier under test are obtained in real time. The moment when the input optical power reaches the preset target power is recorded as the characteristic moment; the optical spectrum of the optical pulse signal and the output signal at each characteristic moment is obtained respectively; and the wavelength of the optical pulse signal and the pump light source are obtained respectively; The first confidence level of the input optical power at each characteristic moment is determined by analyzing the dispersion and average distribution of the pump power at all moments within a preset time period after each characteristic moment; the second confidence level of the input optical power at each characteristic moment is determined by measuring the fluctuation and average level of the input optical power at all moments within a preset time period after each characteristic moment; and the third confidence level of the input optical power at each characteristic moment is determined by comparing the difference in the optical spectrum between the optical pulse signal and the output signal at each characteristic moment. Based on the first confidence level, the second confidence level, and the third confidence level, determining a comprehensive confidence level of the input optical power at each characteristic moment; recording the ratio of the output optical power to the input optical power at each moment as the gain, and based on the comprehensive confidence level, performing a weighted fitting of the output optical power and gain at the characteristic moments corresponding to all different preset target powers closest to the current moment before the current moment; Based on the fitting curve, the difference between the average level of gain and the average level of all pump powers at all times in the preset period before the current moment, and the difference between the wavelength of the optical pulse signal and the wavelength of the pump light source, a multi-channel comprehensive test is performed on the current channel of the optical fiber amplifier under test at the current moment.

2. The multi-channel comprehensive testing method for an Erbium-Ytterbium co-doped high-power optical fiber amplifier according to claim 1, wherein: The preset target power includes: -5dBm, -3.5dBm, -2dBm, -0.5dBm, 1dBm, 2.5dBm, 4dBm, 5.5dBm, 7dBm, 8.5dBm, and 10dBm.

3. The multi-channel comprehensive testing method for an Erbium-Ytterbium co-doped high-power optical fiber amplifier according to claim 1, wherein: The method for determining the first confidence level of the input optical power at each characteristic moment is: The standard deviation and mean of the pump power at all moments within a preset time period after each characteristic moment are calculated, and the reciprocal of the product of the normalized value of the standard deviation and the normalized value of the reciprocal of the mean is taken as the first confidence level of the input optical power at each characteristic moment.

4. The multi-channel comprehensive testing method for an Erbium-Ytterbium co-doped high-power optical fiber amplifier according to claim 1, wherein: The method for determining the second confidence level of the input optical power at each characteristic moment is: Calculate the standard deviation and mean of the input optical power at all moments within a preset time period after each characteristic moment, and record them as the first eigenvalue and the second eigenvalue respectively. Take the reciprocal of the product of the normalized value of the first eigenvalue and the normalized value of the reciprocal of the second eigenvalue as the second confidence level of the input optical power at each characteristic moment.

5. The multi-channel comprehensive testing method for an Erbium-Ytterbium co-doped high-power optical fiber amplifier according to claim 1, wherein: The method for determining the interference characteristic value of the input optical power at each characteristic moment is: Spectra within a preset wavelength range are extracted from the spectrum diagram of the optical pulse signal at each characteristic moment, and are recorded as a first spectrum and a second spectrum, respectively. The mean of the spectral intensity at all wavelengths other than the wavelength corresponding to the optical pulse signal in the first spectrum and the mean of the spectral intensity at all wavelengths other than the wavelength corresponding to the optical pulse signal in the second spectrum are calculated, and are recorded as a first mean value and a second mean value, respectively. The difference between the second mean value and the first mean value is divided by the first mean value, and the result is used as the interference characteristic value of the input optical power at each characteristic moment.

6. The multi-channel comprehensive testing method for an Erbium-Ytterbium co-doped high-power optical fiber amplifier according to claim 1, wherein: The third confidence level of the input optical power at each characteristic moment is the inverse of the normalized value of the interference characteristic value of the input optical power at each characteristic moment.

7. The multi-channel comprehensive testing method for an Erbium-Ytterbium co-doped high-power optical fiber amplifier according to claim 1, wherein: The comprehensive confidence level of the input optical power at each characteristic moment is the product of the normalized value of the first confidence level, the normalized value of the second confidence level, and the normalized value of the third confidence level of the input optical power at each characteristic moment.

8. The multi-channel comprehensive testing method for an Erbium-Ytterbium co-doped high-power optical fiber amplifier according to claim 1, wherein: The weighted fitting of the output optical power and gain at characteristic moments corresponding to all different preset target powers closest to the current moment before the current moment includes: The output optical power and gain at each characteristic moment are combined into a binary group, and all binary groups corresponding to the characteristic moments of all different preset target powers closest to the current moment before the current moment are used as inputs based on the weighted fitting algorithm, wherein the normalized value of the comprehensive confidence of the input optical power at the corresponding characteristic moment is used as the weight of the binary group, and the fitting curve is output.

9. The multi-channel comprehensive testing method for Erbium-Ytterbium co-doped high-power optical fiber amplifier according to claim 1, characterized in that: The performing of a multi-channel comprehensive test on the current channel of the optical fiber amplifier to be tested at the current moment includes: The saturated output optical power of the optical fiber amplifier under test at the current moment is calculated based on the fitting curve, and is used as the saturated output optical power test result of the current channel of the optical fiber amplifier under test at the current moment; Calculate the gain average at all times in a preset period before the current moment divided by the pump power average at all times as the power conversion efficiency test result of the current channel of the optical fiber amplifier under test at the current moment; The ratio of the wavelength of the optical pulse signal to the wavelength of the pump light source is calculated, and the product of the ratio and the power conversion efficiency test result is used as the quantum conversion efficiency test result of the current channel of the optical fiber amplifier to be tested at the current moment.

10. A multi-channel integrated test device for an Erbium-Ytterbium co-doped high-power optical fiber amplifier, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the multi-channel comprehensive testing method of an erbium-ytterbium co-doped high-power optical fiber amplifier as described in any one of claims 1 to 9 are implemented.

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