Light vector analysis device and method for unbalanced cross-polarization inquiry

Abstract

The invention belongs to the technical field of light wave element measurement, and particularly relates to a light vector analysis device and method for unbalanced cross-polarization inquiry, and the device comprises a sweep frequency light source module, a cross-polarization generation module, a measurement interferometer module, a polarization diversity detection module, and a module for obtaining information of a device to be measured. The device is characterized in that an orthogonal polarization generation module composed of a coupler and a polarization beam combiner generates a pair of orthogonal polarization frequency sweeping lasers with a high extinction ratio, and a complicated polarization regulation and control process with the extinction ratio difficult to guarantee is not needed any more. Meanwhile, the tail fibers of all the optical fiber devices in the device are common single-mode optical fibers, so that the error influence of polarization crosstalk on the measurement result is effectively avoided, and the spectral response characteristic measurement precision of the optical device to be measured is greatly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of optical testing, and particularly relates to a light vector analysis device and method based on non-equilibrium orthogonal polarization interrogation. BACKGROUND

[0002] Light vector analysis technology is an important measurement technology for characterizing the spectral response of optoelectronic devices, and is widely used in the fields of photonic integrated chip systems and optical fiber communication systems, and can accurately measure the spectral response of devices. At present, two major categories of light vector transmission characteristic test methods have been developed based on different optical principles—carrier sideband beat frequency method (electrical modulation method) and orthogonal polarization interference method (optical interference method). The main principle of the light vector analysis technology based on the electrical modulation method is to use a modulator to generate a light single sideband, and by analyzing the amplitude and phase changes of the carrier and sideband after passing through the device under test, the frequency response of the device is obtained. However, the measurement range of this scheme is limited by the working bandwidth of the electro-optical modulator; the light vector analysis technology based on the optical interference method uses a pair of linearly swept continuous lasers with fixed time delay and orthogonal polarization as interrogation light, and uses polarization diversity detection for coherent detection, which can completely characterize the transmission matrix of the device under test, and has the advantages of measuring vector characteristics including polarization characteristics and wide wavelength measurement range, but its test precision depends on the polarization alignment state of the interferometer, and the reliability and efficiency of the test are limited.

[0003] The electrical modulation method was proposed by Roman J. et al. of the U.S. Navy Laboratory in 1998. This method generates a swept laser by driving a broadband modulator with a swept microwave signal and uses it for the device under test, and obtains the amplitude and phase characteristics by detecting the swept laser and the carrier beat frequency.

[0004] In 2021, Professor Pan Shilong of Nanjing University of Aeronautics and Astronautics published a paper (Li S, Qing T, Wang L, et al. Optical vector analyzer with time-domain analysis capability [J]. Optics Letters, 2021, 46(2).), which proposed an electrical swept method amplitude / phase spectrum distribution measurement scheme with time-domain analysis capability. The core of this scheme is to generate a low-coherence light carrier by loading an electrical broadband signal on continuous light through acousto-optic modulation, and to measure the total frequency response of the device under test by combining light single sideband modulation and vector balance detection, with a frequency resolution of 5MHz.

[0005] In 2022, Professor Zhang Weifeng of Beijing University of Technology published a paper (Wang B, Fan X, Zhao S, et al. Ultrahigh-resolution optical vector analyzer for multiple parallel measurements based on frequency-domain analysis [J]. Optics Letters, 2022, 47(9).), which used a distributed feedback semiconductor laser to generate a linear sweep optical signal and used a reference interferometer to calibrate the amplitude and phase of the measurement signal in real time, thereby eliminating the effects of laser power fluctuations and system nonlinearities. A frequency resolution of 220 kHz was achieved, but the measurement bandwidth was only 18.5 GHz.

[0006] Therefore, the electrical modulation method has a relatively narrow wavelength range and usually does not have the ability to test the polarization dimension. The optical interference method, although it has a lower frequency resolution, has a wider wavelength range and can further expand the testing ability of the polarization dimension.

[0007] The optical interference method was proposed by M. E. Froggatt. et al. of the American Luna Company in 2005 (D. K. Gifford, B. J. Soller, M. S. Wolfe, and M. E. Froggatt. Optical vector network analyzer for single-scan measurements of loss, group delay, and polarization mode dispersion [J]. Applied Optics, 2005, 44(34):7282-7286.). This method uses a pair of sweep lasers with fixed time delay and orthogonal polarization to interrogate the device under test, and measures the polarization transmission matrix of the device by using orthogonal polarization detection. In addition to amplitude and phase parameters, it can also obtain the spectral distribution characteristics of polarization parameters. The measurement wavelength range depends on the tunable laser and can cover the C+L communication band. However, this scheme requires complex orthogonal polarization control, and the extinction ratio is difficult to guarantee, resulting in larger measurement errors and affecting the measurement accuracy and stability of the system.

[0008] In 2023, Yu Zhang et al. of Guangdong University of Technology proposed an online polarization alignment method (an optical vector analysis device and method for online polarization alignment, CN116222979A). This method is based on the Bayesian optimization algorithm. By introducing a data preprocessing method of trigonometric function transformation, the problem of slow convergence caused by a large number of local extreme values in the optimization objective function is solved. By measuring the signal when the device under test (DUT) is connected, online polarization alignment is achieved, and measurement results consistent with commercial OVA are obtained.

[0009] In the same year, the research group proposed a cascaded polarization maintaining interferometer scheme (a polarization-free optical vector analysis device based on a cascaded polarization maintaining interferometer, application number: 202310422850.X). By using the polarization stability of the polarization maintaining fiber, orthogonal polarization output with high extinction ratio is achieved. However, the measurement accuracy is limited by the polarization crosstalk.

[0010] In summary, the optical vector analysis technology based on optical interference method has the significant advantages of large measurement range and full measurement capability. However, its measurement accuracy is limited by the influence of polarization misalignment. The present invention effectively suppresses the measurement error caused by polarization misalignment. SUMMARY

[0011] The present invention aims to provide an optical vector analysis device and method with short measurement time and simple structure, and a non-balance orthogonal polarization interrogation optical vector analysis device and method, which includes a swept light source module 1, an orthogonal polarization generation module 2, a measurement interferometer module 3, a polarization diversity detection module 4, and a device under test information acquisition module 5. The features are as follows:

[0012] The swept light source module 1 includes a tunable laser source 101, a first coupler 102, a fifth coupler 103, a third delay fiber 104, a sixth coupler 105, and a balanced detector 106. The tunable laser source 101 generates linearly swept continuous light with a wavelength that changes over time at a rate γ. After being split by the first coupler 102, the light is injected into the fifth coupler 103 and the orthogonal polarization generation module 2. The fifth coupler 103 divides the light from the first coupler 102 into two beams, one of which is injected into the fifth coupler first output 103a, and the other of which is injected into the third delay fiber 104 via the fifth coupler second output 103b. The two beams are combined in the sixth coupler 105 and then divided into two beams, which are then injected into the balanced detector 106 for differential detection. The interference fringe signal after photoelectric conversion is injected into the interference fringe acquisition module 405;

[0013] The orthogonal polarization generation module 2 comprises a second coupler 201, a first delay optical fiber 202, an optical switch 203 and a polarization beam combiner 204. The linear sweep continuous light is injected into the second coupler 201 and is divided into two beams. One of the two beams passes through the first output end 201a of the second coupler, then passes through the optical switch 203, and is then injected into the polarization beam combiner 204. The other beam is injected into the second output end 201b of the second coupler with the first delay optical fiber 202, and is then injected into the polarization beam combiner 204. After the two beams of light output by the second coupler 201 pass through the polarization beam combiner 204, the light with each polarization direction is filtered out, and then the light is injected into the measurement interferometer module 3. The time delay difference between the two arms of the orthogonal polarization generation module 2 is τ.

[0014] The measurement interferometer module 3 comprises a third coupler 301, a second delay optical fiber 303, a device to be measured 302 and a fourth coupler 304. The output light of the orthogonal polarization generation module 2 is divided into two beams by the third coupler 301. One of the two beams is input into the first input end 304a of the fourth coupler after passing through the device to be measured 302 from the first output end 301a of the third coupler. The other beam is injected into the second delay optical fiber 303 after passing through the second output end 301b of the third coupler. The output light is then injected into the second input end 304b of the fourth coupler. After the two beams of light are combined in the fourth coupler 304, the light is input into the polarization diversity detection module 4. The time delay difference between the two arms of the measurement interferometer module 3 is τ. m ;

[0015] The polarization diversity detection module 4 comprises a polarization controller 401, a polarization beam splitter 402, a p detector 403, an s detector 404 and an interference fringe acquisition module 405. The output light of the measurement interferometer module 3 passes through the polarization controller 401, is divided into two beams by the polarization beam splitter 402 according to the orthogonal polarization directions, and is then injected into the p detector 403 and the s detector 404, respectively. The interference fringe signals obtained by photoelectric conversion are injected into the interference fringe acquisition module 405, and are then converted into digital signals p polarization interference fringe 405a and s polarization interference fringe 405b after analog-digital conversion.

[0016] Before actual measurement, the polarization controller 401 needs to be adjusted to make the reference arm of the measurement interferometer module 3 reach the balanced polarization alignment state.

[0017] After the reference arm of the measurement interferometer module 3 reaches the balanced polarization alignment state, the optical switch 203 is controlled to be in the connected state, and the first output end 301a of the third coupler and the first input end 304a of the fourth coupler are connected. The measurement amplitude error correction matrix ;

[0018] Then, the optical switch 203 is kept in the connected state, the device to be measured 302 is connected, and actual measurement is performed.

[0019] The device information acquisition module 5 comprises a characteristic filtering extraction module 501 and a transmission characteristic acquisition module 502. The p-polarized interference fringes 405a and s-polarized interference fringes 405b are input into the characteristic filtering extraction module 501, and the interference peaks with time delays of , are filtered, and the initial device transmission matrix composed after processing can be expressed as:

[0020]

[0021] wherein A is an amplitude error coefficient, containing amplitude fluctuation of the probe light and loss information of the optical path device, a, b, c and d are device transmission matrix elements, is a polarization rotation angle of the orthogonal polarization probe light in the optical path from the reference arm to the polarization beam splitter 402;

[0022] In the transmission matrix correction module 502, the amplitude error correction matrix is used to correct the error coefficient A of the transmission matrix .

[0023] Finally, the amplitude, phase, polarization and other optical vector transmission characteristics of the device under test 302 are acquired in the transmission characteristic acquisition module 503.

[0024] The optical vector analysis device and method of unbalanced orthogonal polarization interrogation according to claim 1 are characterized in that:

[0025] The tail fibers and delay optical fibers of all devices in the optical path are ordinary single-mode optical fibers.

[0026] The optical vector analysis device and method of unbalanced orthogonal polarization interrogation according to claim 1 are characterized in that:

[0027] Before actual measurement, the reference arm of the measurement interferometer module 3 needs to be brought to an unbalanced polarization alignment state, specifically: the optical switch 203 is in a non-communication state, the device under test 302 is not connected into the measurement interferometer module 3, and the output light of the orthogonal polarization generation module 2 passes through the reference arm and the polarization controller 401 of the measurement interferometer module 3, and the polarization angle of the output light is . The polarization controller 401 is adjusted until the optical powers measured by the p detector 403 and the s detector 404 are equal.

[0028] The optical vector analysis device and method of unbalanced orthogonal polarization interrogation according to claim 1 are characterized in that:

[0029] ​After adjusting the polarization controller 401, the control light switch 203 is in the connected state, and the first output end 301a of the third coupler and the first input end 304a of the fourth coupler are connected, so as to perform calibration measurement on the measurement parameters in actual measurement, and interference fringe signals of the p detector 403 and the s detector 404 are collected to form an amplitude error correction matrix Then, the device under test 302 is connected to perform actual measurement.

[0030] The optical vector analysis device and method for non-equilibrium orthogonal polarization interrogation according to claim 1 are characterized in that:

[0031] In the actual measurement process, the control light switch 203 is in the connected state, and the first output end 301a of the third coupler and the first input end 304a of the fourth coupler are connected to the two ends of the device under test, respectively, so as to collect interference fringe signals of the p detector 403 and the s detector 404 to form an initial transmission matrix of the device under test .

[0032] The optical vector analysis device and method for non-equilibrium orthogonal polarization interrogation according to claim 1 are characterized in that:

[0033] The interference fringe collection module 405 collects output signals from the p detector 403, the s detector 404 and the balanced detector 106, and outputs p polarization interference fringes 405a, s polarization interference fringes 405b, sampling trigger fringes 106a, sampling trigger fringes (106a) and sampling trigger fringes (106a) after waveform shaping as the sampling trigger signal (106b) of the interference fringe collection module (405).

[0034] The optical vector analysis device for non-equilibrium orthogonal polarization interrogation according to claim 1 is characterized in that:

[0035] In the feature filtering extraction module 501, after Fourier transform of the p polarization interference fringes 405a and the s polarization interference fringes 405b, corresponding time domain signals are obtained, and the positions of the feature peaks are determined in the time domain according to the time delay τ of the orthogonal polarization generation module 2 and the time delay τ of the measurement interferometer module 3 m The positions of the two feature peaks are and The characteristic peaks of the p-polarized interference fringe 405a are extracted using the first bandpass filter 5011 and the second bandpass filter 5012, respectively. The characteristic peaks of the s-polarized interference fringe 405b are extracted using the third bandpass filter 5013 and the fourth bandpass filter 5014, respectively. Then, the four extracted characteristic peaks are sequentially subjected to inverse Fourier transform and Hilbert transform to form a 2×2 complex matrix. In the transmission matrix correction module 502, the amplitude error correction matrix is ​​used... Initial transfer matrix of the device under test The amplitude error coefficient A is corrected by taking the inverse of the amplitude error correction matrix. He will be ordered to ride on the left. , to obtain the matrix :

[0036]

[0037] This is the device transfer matrix after amplitude error correction;

[0038] The optical vector analysis device for non-equilibrium orthogonal polarization interrogation according to claim 1 is characterized in that:

[0039] Finally, the amplitude, phase, and polarization transmission characteristics of the device are calculated in the transmission characteristic acquisition module 503, specifically as follows:

[0040] Insertion loss of the device:

[0041]

[0042] Where a, b, c, and d are the normalized device transmission matrix elements;

[0043] Group delay of the device:

[0044]

[0045] Polarization-dependent loss of the device:

[0046]

[0047] in, , Separate matrices Maximum eigenvalue and minimum eigenvalue ( (representing the conjugate transpose), representing the maximum and minimum transmittance of the device under test when the input light is in any different polarization state;

[0048] Polarization mode dispersion of the device:

[0049]

[0050] wherein, , are two eigenvalues of the matrix .

[0051] The present application has the advantages that: the present application is a light vector analysis device for non-balance orthogonal polarization interrogation, polarization combiner 204 is introduced in the orthogonal polarization generation module 2 to ensure the orthogonal polarization output, and only simple polarization regulation is needed in the calibration process to realize polarization alignment, and the measurement error caused by the traditional OVA polarization misalignment is inhibited. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 It is a schematic diagram of a light vector analysis device for non-balance orthogonal polarization interrogation;

[0053] The Figure 1 , 1 - sweep light source module; 2 - orthogonal polarization generation module; 3 - measurement interference module; 4 - polarization diversity detection module; 5 - device information acquisition module to be measured; 101 - tunable laser source; 102 - first coupler; 103 - fifth coupler; 103a - first output end of the fifth coupler; 103b - second output end of the fifth coupler; 104 - third delay optical fiber; 105 - sixth coupler; 106 - balanced detector; 201 - second coupler; 201a - first output end of the second coupler; 201b - second output end of the second coupler; 202 - second delay optical fiber; 203 - optical switch; 204 - polarization combiner; 301 - third coupler; 301a - first output end of the third coupler; 301b - second output end of the third coupler; 302 - device to be measured; 303 - second delay optical fiber; 304 - fourth coupler; 304a - first input end of the fourth coupler; 304b - second input end of the fourth coupler; 401 - polarization controller; 402 - polarization beam splitter; 403 - p detector; 404 - s detector; 405 - interference fringe acquisition module; 405a - p polarization interference fringe; 405b - s polarization interference fringe; 501 - characteristic filter extraction module; 502 - transmission matrix correction module; 503 - transmission characteristic acquisition module.

[0054] Figure 2 It is the amplitude response of the p detector;

[0055] The Figure 2 , A - time delay difference τ of the orthogonal polarization generation module 2 corresponding peak; B - difference of the time delay difference of the measurement interference module 3 and the orthogonal polarization generation module 2 corresponding peak; C - time delay difference τ of the measurement interference module 3m ; D - sum of the delay difference of the measurement interferometer 3 and the orthogonal polarization generation module 2 corresponding peak; 5011 first band-pass filter; 5012 second band-pass filter.

[0056] Figure 3 is the amplitude response of the s detector;

[0057] attached Figure 3 : E - the delay difference of the orthogonal polarization generation module 2 corresponding peak; F - the difference of the delay difference of the measurement interferometer 3 and the orthogonal polarization generation module 2 corresponding peak; G - the delay difference of the measurement interferometer 3 m ; H - sum of the delay difference of the measurement interferometer 3 and the orthogonal polarization generation module 2 corresponding peak; 5013 third band-pass filter; 5014 fourth band-pass filter.

[0058] Figure 4 is a comparison chart of the insertion loss test results of the Bragg grating by the non-balance orthogonal polarization interrogation optical vector analysis device and the commercial instrument LUNA OVA5100;

[0059] attached Figure 4 : 601 is a curve of the group delay test results of the Bragg grating by the non-balance orthogonal polarization interrogation optical vector analysis device, and 602 is a curve of the group delay test results of the Bragg grating by the commercial instrument LUNA OVA5100.

[0060] Figure 5 is a comparison chart of the group delay test results of the Bragg grating by the non-balance orthogonal polarization interrogation optical vector analysis device and the commercial instrument LUNA OVA5100;

[0061] attached Figure 5 : 701 is a curve of the group delay test results of the Bragg grating by the non-balance orthogonal polarization interrogation optical vector analysis device, and 702 is a curve of the group delay test results of the Bragg grating by the commercial instrument LUNA OVA5100.

[0062] Figure 6 is a comparison chart of the polarization-dependent loss test results of the Bragg grating by the non-balance orthogonal polarization interrogation optical vector analysis device and the commercial instrument LUNA OVA5100;

[0063] attached Figure 6 : 801 is a curve of the polarization-dependent loss test results of the Bragg grating by the non-balance orthogonal polarization interrogation optical vector analysis device, and 802 is a curve of the polarization-dependent loss test results of the Bragg grating by the commercial instrument LUNA OVA5100. Detailed Implementation

[0064] To clearly illustrate the present invention, a light vector analysis device for unbalanced orthogonal polarization interrogation, the invention will be further described in conjunction with embodiments and accompanying drawings, but this should not be construed as limiting the scope of protection of the invention.

[0065] The main optoelectronic devices and their parameters are as follows:

[0066] The tunable laser source 101 is a Keysight 81606A laser. The wavelength tuning range during testing is 1535-1565nm, and the sweep rate is 30nm / s.

[0067] The p detector 403 and s detector 404 are single-ended detectors from Aoxiu Information Technology Co., Ltd., with a bandwidth of 15MHz; the balanced detector 106 is a balanced detector from Aoxiu Information Technology Co., Ltd., with a bandwidth of 80MHz.

[0068] The data acquisition card model is M4i:4471-x8, the sampling rate is 31.25MHz, and the maximum acquisition voltage is 2.5V;

[0069] The first coupler 102 has a beam splitting ratio of 99:1, with 99% of the light input to the orthogonal polarization generation module 2 and 1% of the light input to the fifth coupler 103; the second coupler 201, the third coupler 301, the fourth coupler 304, the fifth coupler 103 and the sixth coupler 105 all have beam splitting ratios of 50:50, insertion losses of less than 0.5dB, operating wavelengths of 1550nm±40nm, and fiber optic pigtail lengths of 1m.

[0070] The polarization controller 401 is a three-ring polarization controller with a length of 2m;

[0071] The polarization combiner 204 operates at a wavelength of 1550nm±40nm, and the pigtail length is 1m.

[0072] The device under test 302 is a fiber Bragg grating (FBG). The working center wavelength of the FBG test port is 1550nm, the length of the pigtails at both ends is 1m, the center-to-center distance of the FBG is 10cm, the bandwidth is 0.3nm, and the reflectivity is greater than 99%.

[0073] The first delay fiber 202 and the third delay fiber 104 are both ordinary single-mode fibers, each with a length of 10m.

[0074] The second delay fiber 303 is a common single-mode fiber, and its length is 40m.

[0075] The polarization beam splitter 402 operates at a wavelength of 1550nm±40nm, and the pigtail length is 1m.

[0076] A kind of non-equilibrium orthogonal polarization inquiry optical vector analysis device and method, test method is as follows:

[0077] Tunable laser source 101 generates frequency linear sweep continuous light varying with time , after first coupler 102 beam splitting, one is injected into fifth coupler 103, another is injected into orthogonal polarization generation module 2,

[0078] After being injected into fifth coupler 103, it is divided into two beams, one is injected into fifth coupler first coupler output end 103a, another is injected into fifth coupler second coupler output end 103b and injected into third delay optical fiber 104, two beams are combined in sixth coupler 105 and then divided into two beams, and then jointly injected into balanced detector 106 to carry out differential detection, after photoelectric conversion, interference fringe signal is injected into interference fringe acquisition module 405;

[0079] Before actual measurement, it needs to make the reference arm of measurement interferometer module 3 reach balanced polarization alignment state, specifically: make optical switch 203 be in non-communication state, while the device under test 302 is not accessed into measurement interferometer module 3, the output light of orthogonal polarization generation module 2 passes through the reference arm of measurement interferometer module 3 and polarization controller 401, and the polarization angle of output light is , adjust polarization controller 401 until the optical powers measured by p detector 403 and s detector 404 are equal.

[0080] After adjusting polarization controller 401, control optical switch 203 to be in communication state, and connect the first output end 301a of third coupler and the first input end 304a of fourth coupler, to carry out calibration measurement with the measurement parameters in actual measurement, interference fringe signals of p detector 403 and s detector 404 are acquired, which are used to constitute amplitude error correction matrix , then, access the device under test 302, and carry out actual measurement.

[0081] In the actual measurement process, control optical switch 203 to be in communication state, and connect the first output end 301a of third coupler and the first input end 304a of fourth coupler to the two ends of the device under test respectively, interference fringe signals of p detector 403 and s detector 404 are acquired, which are used to constitute initial transmission matrix of the device under test ;

[0082] The interference fringe acquisition module 405 acquires output signals from p detector 403, s detector 404 and balanced detector 106, and outputs as p polarization interference fringe 405a, s polarization interference fringe 405b respectively, sampling trigger fringe 106a, and the signal 106b after waveform shaping of sampling trigger fringe 106a is used as the sampling trigger signal of interference fringe acquisition module 405.

[0083] In the feature filtering extraction module 501, after Fourier transforming the p-polarized interference fringe 405a and the s-polarized interference fringe 405b, the corresponding time-domain signals are obtained. Based on the time delay τ of the orthogonal polarization generation module 2 and the time delay τ of the interferometer module 3, the signal is then processed. m The positions of the characteristic peaks in the time domain are determined, and the positions of the two characteristic peaks are respectively... and The characteristic peaks of the p-polarized interference fringe 405a are extracted using the first bandpass filter 5011 and the second bandpass filter 5012, respectively. The characteristic peaks of the s-polarized interference fringe 405b are extracted using the third bandpass filter 5013 and the fourth bandpass filter 5014, respectively. Then, the four extracted characteristic peaks are subjected to inverse Fourier transform and Hilbert transform in sequence to form a 2×2 complex matrix. In the transmission matrix correction module 502, the amplitude error correction matrix is ​​used according to formula (2). Initial transfer matrix of the device under test The amplitude error coefficient A is corrected;

[0084] Finally, in the transmission characteristic acquisition module 503, the amplitude, phase, and polarization transmission characteristics of the device are calculated using formulas (3), (4), (5), and (6).

Claims

1. A light vector analysis device and method for non-equilibrium orthogonal polarization interrogation, comprising a swept frequency light source module (1), an orthogonal polarization generation module (2), a measurement interferometer module (3), a polarization diversity detection module (4), and a device-under-test information acquisition module (5), characterized in that: The frequency sweeping light source module (1) includes a tunable laser source (101), a first coupler (102), a fifth coupler (103), a third delay fiber (104), a sixth coupler (105), and a balanced detector (106). The tunable laser source (101) generates a linear frequency sweeping continuous light whose frequency changes with time. After being split by the first coupler (102), one beam is injected into the fifth coupler (103), and the other beam is injected into the orthogonal polarization generation module (2). The fifth coupler (103) splits the light from the first coupler (102) into two beams. One beam is injected into the first output end (103a) of the fifth coupler, and the other beam is injected into the third delay fiber (104) via the second output end (103b) of the fifth coupler. The two beams are combined in the sixth coupler (105) and then split into two beams. They are then injected into the balanced detector (106) for differential detection. The interference fringe signal after photoelectric conversion is injected into the interference fringe acquisition module (405). The orthogonal polarization generation module (2) includes a second coupler (201), a first delay fiber (202), an optical switch (203), and a polarization combiner (204); wherein the linear sweep frequency continuous light injected into the second coupler (201) is split into two beams, one beam passes through the first output end (201a) of the second coupler and then passes through the optical switch (203), and is then injected into the polarization combiner (204), and the other beam is injected into the second output end (201b) of the second coupler with the second delay fiber (202), and is then injected into the polarization combiner (204). After the two beams of light output from the second coupler (201) pass through the polarization combiner (204), light in one polarization direction of each beam is filtered out, and then injected into the measurement interferometer module (3). The time delay difference between the two arms of the orthogonal polarization generation module (2) is τ. The measurement interferometer module (3) includes a third coupler (301), a second delay fiber (303), a device under test (302), and a fourth coupler (304). The output light of the orthogonal polarization generation module (2) is split into two beams by the third coupler (301). One beam passes through the device under test (302) from the first output end (301a) of the third coupler and is then input to the first input end (304a) of the fourth coupler. The other beam passes through the second output end (301b) of the third coupler and is then injected into the second delay fiber (303). The output light is then injected into the second input end (304b) of the fourth coupler. The two beams are combined at the fourth coupler (304) and then input into the polarization diversity detection module (4). The time delay difference between the two arms of the measurement interferometer module (3) is τ. m ; The polarization diversity detection module (4) includes a polarization controller (401), a polarization beam splitter (402), a p detector (403), an s detector (404), and an interference fringe acquisition module (405). The output light of the measurement interferometer module (3) passes through the polarization controller (401) and is split into two beams by the polarization beam splitter (402) according to the orthogonal polarization direction. The beams are injected into the p detector (403) and the s detector (404) respectively. The interference fringe signal obtained by photoelectric conversion is injected into the interference fringe acquisition module (405). After analog-to-digital conversion, it is converted into digital signals p-polarized interference fringe (405a) and s-polarized interference fringe (405b) respectively. Before the actual measurement, the polarization controller (401) needs to be adjusted so that the reference arm of the measurement interferometer module (3) reaches a balanced polarization alignment state. After the reference arm of the measurement interferometer module (3) reaches the balanced polarization alignment state, the control optical switch (203) is in the connected state, and at the same time, the first output terminal (301a) of the third coupler and the first input terminal (304a) of the fourth coupler are connected, and the measurement amplitude error correction matrix is ​​measured. ; Subsequently, while keeping the optical switch (203) in the connected state, the device under test (302) is connected for actual measurement; The device under test (DUT) information acquisition module (5) includes a feature filtering extraction module (501) and a transmission characteristic acquisition module (502). Digital signal p-polarized interference fringes (405a) and s-polarized interference fringes (405b) are input into the feature filtering extraction module (501), and the time delays are respectively... , The interference peaks are filtered, and the resulting initial device transfer matrix is ​​formed. It can be represented as: Where A is the amplitude error coefficient, which includes the amplitude fluctuation of the query light and the loss information of the optical path devices, and a, b, c, and d are the elements of the device transmission matrix, respectively. The polarization rotation angle of the orthogonally polarized interrogating light as it travels through the optical path from the reference arm to the polarization beam splitter (402); In the transmission matrix correction module (502), the amplitude error correction matrix is ​​used. For the above transmission matrix The error coefficient A is corrected; Finally, the amplitude, phase, polarization and other optical vector transmission characteristics of the device under test (302) are obtained in the transmission characteristic acquisition module (503).

2. The optical vector analysis device and method for non-equilibrium orthogonal polarization interrogation according to claim 1, characterized in that: All pigtails and delay fibers in the optical path are ordinary single-mode fibers.

3. The optical vector analysis device and method for non-equilibrium orthogonal polarization interrogation according to claim 1, characterized in that: Before actual measurement, the reference arm of the measurement interferometer module (3) needs to be in a balanced polarization alignment state. Specifically, the optical switch (203) should be in a non-connected state, and the device under test (302) should not be connected to the measurement interferometer module (3). After the output light of the orthogonal polarization generation module (2) passes through the reference arm of the measurement interferometer module (3) and the polarization controller (401), the polarization angle of the output light is: Adjust the polarization controller (401) until the optical power measured by the p detector (403) and the s detector (404) is equal.

4. The optical vector analysis device and method for non-equilibrium orthogonal polarization interrogation according to claim 1, characterized in that: After adjusting the polarization controller (401), the optical switch (203) is switched on, and the first output terminal (301a) of the third coupler and the first input terminal (304a) of the fourth coupler are connected. Calibration measurement is performed using the measurement parameters used in the actual measurement, and the interference fringe signals of the p detector (403) and the s detector (404) are collected to form the amplitude error correction matrix. Then, the device under test (302) is connected to perform actual measurements.

5. The optical vector analysis device and method for non-equilibrium orthogonal polarization interrogation according to claim 1, characterized in that: During the actual measurement process, the optical switch (203) is controlled to be in the connected state. At the same time, the first output terminal (301a) of the third coupler and the first input terminal (304a) of the fourth coupler are connected to the two ends of the device under test, respectively. The interference fringe signals of the p detector (403) and the s detector (404) are collected and used to form the initial transmission matrix of the device under test. .

6. The optical vector analysis device and method for non-equilibrium orthogonal polarization interrogation according to claim 1, characterized in that: The interference fringe acquisition module (405) acquires the output signals from the p detector (403), s detector (404) and balanced detector (106), and outputs them as p-polarized interference fringes (405a) and s-polarized interference fringes (405b), respectively, and a sampling trigger fringe (106a). The signal of the sampling trigger fringe (106a) after waveform shaping is used as the sampling trigger signal (106b) of the interference fringe acquisition module (405).

7. The optical vector analysis device and method for non-equilibrium orthogonal polarization interrogation according to claim 1, characterized in that: In the feature filtering extraction module (501), after Fourier transforming the p-polarized interference fringes (405a) and s-polarized interference fringes (405b), the corresponding time-domain signals are obtained. Based on the time delay τ of the orthogonal polarization generation module (2) and the time delay τ of the measurement interferometer module (3), the signal is obtained. m The positions of the characteristic peaks in the time domain are determined, and the positions of the two characteristic peaks are respectively... and The characteristic peaks of the p-polarized interference fringe (405a) are extracted using the first bandpass filter (5011) and the second bandpass filter (5012), respectively. The characteristic peaks of the s-polarized interference fringe (405b) are extracted using the third bandpass filter (5013) and the fourth bandpass filter (5014), respectively. Then, the four extracted characteristic peaks are subjected to inverse Fourier transform and Hilbert transform respectively to form a 2×2 complex matrix. In the transmission matrix correction module (502), the amplitude error correction matrix is ​​used. Initial transfer matrix of the device under test The amplitude error coefficient A is corrected by taking the inverse of the amplitude error correction matrix. He ordered him to ride on the left. , to obtain the matrix : This is the device transmission matrix after amplitude error correction.

8. The optical vector analysis device and method for non-equilibrium orthogonal polarization interrogation according to claim 1, characterized in that: in The transmission characteristic acquisition module (503) calculates the amplitude, phase, and polarization transmission characteristics of the device, specifically: Insertion loss of the device: Where a, b, c, and d are the normalized device transmission matrix elements; Group delay of the device: Polarization-dependent loss of the device: in, , Separate matrices Maximum eigenvalue and minimum eigenvalue ( (representing the conjugate transpose), representing the maximum and minimum transmittance of the device under test when the input light is in any different polarization state; polarization mode dispersion of the device: in, , For matrix Two eigenvalues.

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