A polarization detection optical equipment polarization measurement error evaluation and decoupling system, evaluation method and decoupling method

Abstract

The present application relates to a kind of polarization measurement error evaluation and decoupling system, evaluation method and decoupling method, in particular to a kind of polarization measurement error evaluation and decoupling system, evaluation method and decoupling method of polarization detection optical equipment, solve the problem that prior art lacks the evaluation method and decoupling method of coupled polarization measurement error introduced by instrument polarization and imaging quality of polarization detection optical equipment.The system includes test beam generation module, analysis unit and information acquisition computer;Test beam generation module includes laser light source, beam collimator, polarizer, beam splitter and the polarization distribution modulation element of light arranged on the reflected light path of beam splitter in order along optical path;Analysis unit is arranged on the output light path of the polarization detection optical equipment to be measured, for acquiring the detection signal outputted therefrom, and extract the required information therefrom, and transmit to information acquisition computer;Information acquisition computer is used to calculate polarization measurement error and decouple coupled polarization measurement error.

Description

Technical Field

[0001] The present invention relates to a polarization measurement error evaluation and decoupling system, an evaluation method and a decoupling method, and in particular to a polarization measurement error evaluation and decoupling system, an evaluation method and a decoupling method for a polarization detection optical device. Background Art

[0002] Optical polarization detection technology utilizes the polarization properties of light to overcome the limitations of traditional intensity imaging, which limits the low-dimensionality of information acquired. It can achieve high-dimensional information acquisition of detected targets in complex environments and is widely used in industrial monitoring, medical diagnosis, scientific remote sensing, astronomical observation, and other fields. Polarization detection optical equipment uses a polarization modulation method to modulate and image the incident light waves from the target through its polarization modulation unit and imaging unit, thereby achieving polarization detection of the target. Therefore, the instrument polarization and imaging quality of polarization detection optical equipment are the main factors that introduce polarization measurement errors, thereby affecting the accuracy of polarization detection.

[0003] To calibrate the polarization measurement error introduced by polarization detection optical devices due to instrument polarization, existing technologies employ a polarization calibration unit consisting of a linear polarizer and a phase delay element. This calibration determines the polarization measurement error and thus improves the polarization detection accuracy of the device. Existing technologies focus on evaluating the polarization measurement error introduced by instrument polarization, but fail to simultaneously assess the polarization measurement error introduced by imaging quality. Consequently, existing technologies lack methods for evaluating the coupled polarization measurement error introduced by polarization detection optical devices due to both instrument polarization and imaging quality. Furthermore, existing technologies also lack methods for decoupling the coupled polarization measurement error introduced by both instrument polarization and imaging quality. Summary of the Invention

[0004] The purpose of the present invention is to solve the technical problem that the prior art lacks an evaluation method for evaluating the coupled polarization measurement error introduced by polarization detection optical equipment due to instrument polarization and imaging quality, as well as a decoupling method for decoupling. By providing a polarization measurement error evaluation and decoupling system, an evaluation method and a decoupling method for polarization detection optical equipment, the present invention provides a polarization measurement error evaluation and decoupling system, an evaluation method and a decoupling method for polarization detection optical equipment.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A polarization measurement error evaluation and decoupling system for a polarization detection optical device is disclosed. The polarization detection optical device to be measured includes a polarization modulation unit and an imaging unit located on an optical path. The system is characterized in that:

[0007] It includes a test beam generating module, an analysis unit and an information acquisition computer;

[0008] The test beam generation module includes a laser light source, a beam collimator, a polarizer, a beam splitter, and a light polarization distribution modulation element arranged in sequence along the light path reflected by the beam splitter;

[0009] The beam collimator is used to collimate the light beam emitted by the laser light source to generate a collimated light beam;

[0010] The polarizer is used to convert the collimated light beam into an isotropic polarized light beam for output;

[0011] The beam splitter is used to reflect the isotropic polarized light beam output by the polarizer to the polarization distribution modulation element of the light;

[0012] The light polarization distribution modulation element is used to modulate the polarization state of the incident isotropic polarized light beam to generate a light beam with a polarization state distribution required for testing;

[0013] The beam splitter is further used to transmit the light beam with the polarization state distribution required for the test generated by the polarization distribution modulation element, so as to be incident on the polarization detection optical device to be tested as a test beam;

[0014] The analysis unit is provided on the output optical path of the polarization detection optical device to be measured, and is used to collect the detection signal output by the polarization detection optical device to be measured, analyze the collected detection signal, extract information required for calculating the polarization measurement error, and then transmit the extracted information required for calculating the polarization measurement error to the information collection computer in real time;

[0015] The information acquisition computer is used to calculate polarization measurement errors and decouple coupled polarization measurement errors introduced by instrument polarization and imaging quality.

[0016] Furthermore, it also includes an optical air-floating platform;

[0017] The test beam generating module, the analyzing unit and the information collecting computer are all arranged on the optical air floating platform.

[0018] Furthermore, the test beam generating module further includes an adjustable iris;

[0019] The adjustable diaphragm is arranged between the beam collimator and the polarizer.

[0020] Furthermore, the analysis unit is a polarization analyzer or detector;

[0021] When the analyzing unit is a detector, the image plane of the imaging unit is arranged to coincide with the focal plane of the detector.

[0022] Furthermore, the light polarization distribution modulation element is a spatial light modulator.

[0023] At the same time, the present invention also provides a method for evaluating polarization measurement errors of a polarization detection optical device. The polarization detection optical device to be measured includes a polarization modulation unit and an imaging unit located on an optical path. The method is special in that it includes the following steps:

[0024] Step 1: Construct the polarization measurement error evaluation and decoupling system of the polarization detection optical device mentioned above, and determine the modulation matrix according to the polarization detection optical device to be measured. ;

[0025] Step 2: The analysis unit in the evaluation and decoupling system constructed in step 1 is selected as a polarization analyzer, and then based on the evaluation and decoupling system, an experiment is conducted to obtain the polarization measurement error introduced by the instrument polarization of the polarization detection optical device to be tested, specifically:

[0026] Step 2.1: Setting parameters of each optical element in the test beam generating module so that the test beam generating module generates a polarization state with isotropic distribution. Test beam ;

[0027] Step 2.2: Make the test beam generated in step 2.1 incident on the polarization detection optical device to be measured;

[0028] Step 2.3: Give the test beam in step 2.2 The incident polarization modulation unit of the polarization detection optical device to be measured applies input nominal parameters and corresponding offsets;

[0029] Step 2.4: The polarization analyzer collects the optical signal output by the polarization detection optical device to be measured after the input nominal parameters and the corresponding offset are applied to the polarization modulation unit in step 2.3, and analyzes the collected optical signal to extract the polarization information of the optical signal. , and then extract the polarization information of the optical signal Transmitting to the information collection computer in real time;

[0030] Step 2.5: The information acquisition computer collects the polarization information of the optical signal transmitted by the polarization analyzer in step 2.4. and the test beam generated in step 2.1 Polarization state The single measurement value of the polarization measurement error introduced by the instrument polarization of the polarization detection optical device to be measured is calculated using the following formula: :

[0031] ;

[0032] Step 2.6: Repeat steps 2.3 to 2.5. During the repeated execution, the nominal parameters and the corresponding offset values ​​applied to the polarization modulation unit in step 2.3 are the same as those in the previous time. When the number of repetitions reaches a preset repetition threshold, calculate the single measurement value of the polarization measurement error introduced by the instrument polarization of the polarization detection optical device to be measured obtained by multiple calculations in step 2.5. Average value , the average value The polarization measurement error of the polarization detection optical device to be measured introduced by the instrument polarization is obtained;

[0033] Step 3: Replace the polarization analyzer in the evaluation and decoupling system based on step 2 with a detector, and then perform the evaluation and decoupling based on the evaluation and decoupling system and the modulation matrix determined in step 1. , conduct experiments to obtain the polarization measurement error introduced by the imaging quality of the polarization detection optical device to be tested, specifically:

[0034] Step 3.1: Setting parameters of each optical element in the test beam generating module so that the test beam generating module generates a polarization state with a polarization distribution difference Test beam ;

[0035] Step 3.2: Make the image plane of the imaging unit of the polarization detection optical device to be tested coincide with the focal plane of the detector, and make the test beam generated in step 3.1 incident on the polarization detection optical device to be measured;

[0036] Step 3.3: Give the test beam in step 3.2 The polarization modulation unit of the incident polarization detection optical device to be measured applies input nominal parameters in each modulation period to modulate the light beam;

[0037] Step 3.4: The detector collects the test beams with different polarization modulation states under the same modulation period. , after applying the input nominal parameters to each modulation cycle of the polarization modulation unit in step 3.3, the output image of the polarization detection optical device to be tested is analyzed, and the image intensity information of the image is extracted from it , and then extract the image intensity information of the image Transmitting to the information collection computer in real time;

[0038] Step 3.5: The information acquisition computer collects the image intensity information of the image transmitted by the detector in step 3.4. , the modulation matrix determined in step 1 and the test beam generated in step 3.1 Polarization state The single measurement value of the polarization measurement error introduced by the polarization detection optical device to be tested due to imaging quality is calculated using the following formula: :

[0039] ;

[0040] Where: Represents the modulation matrix The inverse matrix of

[0041] Step 3.6: Repeat steps 3.3 to 3.5. During the repeated execution, the value of the nominal parameter applied to each modulation cycle of the polarization modulation unit in step 3.3 is the same as the previous one, until the number of repetitions reaches the preset repetition threshold, and the single measurement value of the polarization measurement error introduced by the imaging quality of the polarization detection optical device to be measured obtained by multiple calculations in step 3.5 is calculated. Average value , the average value The polarization measurement error introduced by the polarization detection optical device to be measured due to the imaging quality is obtained;

[0042] Step 4: Based on the evaluation and decoupling system based on step 3, and the modulation matrix determined in step 1 , the nominal parameters and corresponding offset values ​​applied to the polarization modulation unit in step 2.3, and the parameter values ​​set for each optical element in the test beam generating module in step 3.1, are used to conduct an experiment to obtain the coupled polarization measurement error introduced by the polarization instrument and imaging quality of the polarization detection optical device to be tested, specifically:

[0043] Step 4.1: According to the parameter values ​​set for each optical element in the test beam generating module in step 3.1, set the same parameters as in step 3.1 for each optical element in the test beam generating module, so that the test beam generating module generates the same test beam as in step 3.1 ;

[0044] Step 4.2: Make the image plane of the imaging unit of the polarization detection optical device to be tested coincide with the focal plane of the detector, and make the test beam generated in step 4.1 incident on the polarization detection optical device to be measured;

[0045] Step 4.3: According to the nominal parameters and corresponding offset values ​​applied to the polarization modulation unit in step 2.3, the test beam in step 4.2 is The polarization modulation unit of the incident polarization detection optical device to be tested applies input of the nominal parameters and corresponding offsets with the same parameter types and values ​​as those in step 2.3;

[0046] Step 4.4: The detector collects the test beams with different polarization modulation states under the same modulation period. , the image output after the polarization detection optical device to be tested in step 4.3, and the collected image is analyzed to extract the image intensity information from it , and then extract the image intensity information of the image Transmitting to the information collection computer in real time;

[0047] Step 4.5: The information acquisition computer collects the image intensity information of the image transmitted by the detector in step 4.4. , the modulation matrix determined in step 1 and the test beam generated in step 4.1 Polarization state The single measurement value of the coupled polarization measurement error introduced by the polarization instrument and imaging quality of the polarization detection optical device to be measured is calculated using the following formula: :

[0048] ;

[0049] Step 4.6: Repeat steps 4.3 to 4.5 until the number of repetitions reaches a preset repetition threshold, and calculate the single measurement value of the coupled polarization measurement error introduced by the polarization instrument and imaging quality of the polarization detection optical device to be measured obtained by multiple calculations in step 4.5. Average value , the average value The evaluation is completed by obtaining the coupled polarization measurement error introduced by the polarization instrument and the imaging quality of the polarization detection optical device to be measured.

[0050] Furthermore, the polarization modulation unit includes a phase retarder and a linear polarizer located on the optical path;

[0051] In step 2.3, the nominal parameters and corresponding offsets include: phase delay angle of the phase retarder , Phase delay angle of phase retarder Offset , linear polarizer azimuth , and the linear polarizer azimuth Offset ;

[0052] In step 3.3, the nominal parameters of the input applied in each modulation cycle include the phase delay angle of the phase retarder and the linear polarizer azimuth .

[0053] In addition, the present invention also provides a method for decoupling polarization measurement errors of a polarization detection optical device. The polarization detection optical device to be measured includes a polarization modulation unit and an imaging unit located on an optical path. The method is special in that it includes the following steps:

[0054] Step 1: Construct the polarization measurement error evaluation and decoupling system of the polarization detection optical device mentioned above, and determine the modulation matrix according to the polarization detection optical device to be measured. ;

[0055] Step 2: The analysis unit in the evaluation and decoupling system constructed in step 1 is selected as a polarization analyzer, and then based on the evaluation and decoupling system, an experiment is conducted to obtain the polarization measurement error introduced by the instrument polarization of the polarization detection optical device to be tested, specifically:

[0056] Step 2.1: Setting parameters of each optical element in the test beam generating module so that the test beam generating module generates a polarization state with isotropic distribution. Test beam ;

[0057] Step 2.2: Make the test beam generated in step 2.1 incident on the polarization detection optical device to be measured;

[0058] Step 2.3: Give the test beam in step 2.2 The incident polarization modulation unit of the polarization detection optical device to be measured applies input nominal parameters and corresponding offsets;

[0059] Step 2.4: The polarization analyzer collects the optical signal output by the polarization detection optical device to be measured after the input nominal parameters and the corresponding offset are applied to the polarization modulation unit in step 2.3, and analyzes the collected optical signal to extract the polarization information of the optical signal. , and then extract the polarization information of the optical signal Transmitting to the information collection computer in real time;

[0060] Step 2.5: The information acquisition computer collects the polarization information of the optical signal transmitted by the polarization analyzer in step 2.4. and the test beam generated in step 2.1 Polarization state The single measurement value of the polarization measurement error introduced by the instrument polarization of the polarization detection optical device to be measured is calculated using the following formula: :

[0061] ;

[0062] Step 2.6: Repeat steps 2.3 to 2.5. During the repeated execution, the nominal parameters and the corresponding offset values ​​applied to the polarization modulation unit in step 2.3 are the same as those in the previous time. When the number of repetitions reaches a preset repetition threshold, calculate the single measurement value of the polarization measurement error introduced by the instrument polarization of the polarization detection optical device to be measured obtained by multiple calculations in step 2.5. Average value , the average value The polarization measurement error of the polarization detection optical device to be measured introduced by the instrument polarization is obtained;

[0063] Step 3: Replace the polarization analyzer in the evaluation and decoupling system based on step 2 with a detector, and then perform the evaluation and decoupling based on the evaluation and decoupling system and the modulation matrix determined in step 1. , conduct experiments to obtain the polarization measurement error introduced by the imaging quality of the polarization detection optical device to be tested, specifically:

[0064] Step 3.1: Setting parameters of each optical element in the test beam generating module so that the test beam generating module generates a polarization state with a polarization distribution difference Test beam ;

[0065] Step 3.2: Make the image plane of the imaging unit of the polarization detection optical device to be tested coincide with the focal plane of the detector, and make the test beam generated in step 3.1 incident on the polarization detection optical device to be measured;

[0066] Step 3.3: Give the test beam in step 3.2 The polarization modulation unit of the incident polarization detection optical device to be measured applies input nominal parameters in each modulation period to modulate the light beam;

[0067] Step 3.4: The detector collects the test beams with different polarization modulation states under the same modulation period. , after applying the input nominal parameters to each modulation cycle of the polarization modulation unit in step 3.3, the output image of the polarization detection optical device to be tested is analyzed, and the image intensity information of the image is extracted from it , and then extract the image intensity information of the image Transmitting to the information collection computer in real time;

[0068] Step 3.5: The information acquisition computer collects the image intensity information of the image transmitted by the detector in step 3.4. , the modulation matrix determined in step 1 and the test beam generated in step 3.1 Polarization state The single measurement value of the polarization measurement error introduced by the polarization detection optical device to be tested due to imaging quality is calculated using the following formula: :

[0069] ;

[0070] Where: Represents the modulation matrix The inverse matrix of

[0071] Step 3.6: Repeat steps 3.3 to 3.5. During the repeated execution, the value of the nominal parameter applied to each modulation cycle of the polarization modulation unit in step 3.3 is the same as the previous one, until the number of repetitions reaches the preset repetition threshold, and the single measurement value of the polarization measurement error introduced by the imaging quality of the polarization detection optical device to be measured obtained by multiple calculations in step 3.5 is calculated. Average value , the average value The polarization measurement error introduced by the polarization detection optical device to be measured due to the imaging quality is obtained;

[0072] Step 4: Based on the evaluation and decoupling system based on step 3, and the modulation matrix determined in step 1 , the nominal parameters and corresponding offset values ​​applied to the polarization modulation unit in step 2.3, and the parameter values ​​set for each optical element in the test beam generating module in step 3.1, are used to conduct an experiment to obtain the coupled polarization measurement error introduced by the polarization instrument and imaging quality of the polarization detection optical device to be tested, specifically:

[0073] Step 4.1: According to the parameter values ​​set for each optical element in the test beam generating module in step 3.1, set the same parameters as in step 3.1 for each optical element in the test beam generating module, so that the test beam generating module generates the same test beam as in step 3.1 ;

[0074] Step 4.2: Make the image plane of the imaging unit of the polarization detection optical device to be tested coincide with the focal plane of the detector, and make the test beam generated in step 4.1 incident on the polarization detection optical device to be measured;

[0075] Step 4.3: According to the nominal parameters and corresponding offset values ​​applied to the polarization modulation unit in step 2.3, the test beam in step 4.2 is The polarization modulation unit of the incident polarization detection optical device to be tested applies input of the nominal parameters and corresponding offsets with the same parameter types and values ​​as those in step 2.3;

[0076] Step 4.4: The detector collects the test beams with different polarization modulation states under the same modulation period. , the image output after the polarization detection optical device to be tested in step 4.3, and the collected image is analyzed to extract the image intensity information from it , and then extract the image intensity information of the image Transmitting to the information collection computer in real time;

[0077] Step 4.5: The information acquisition computer collects the image intensity information of the image transmitted by the detector in step 4.4. , the modulation matrix determined in step 1 and the test beam generated in step 4.1 Polarization state The single measurement value of the coupled polarization measurement error introduced by the polarization instrument and imaging quality of the polarization detection optical device to be measured is calculated using the following formula: :

[0078] ;

[0079] Step 4.6: Repeat steps 4.3 to 4.5 until the number of repetitions reaches a preset repetition threshold, and calculate the single measurement value of the coupled polarization measurement error introduced by the polarization instrument and imaging quality of the polarization detection optical device to be measured obtained by multiple calculations in step 4.5. Average value , the average value The coupled polarization measurement error introduced by the polarization and imaging quality of the polarization detection optical device to be measured is obtained;

[0080] Step 5: The number of coupled polarization measurement errors introduced by the polarization instrument and imaging quality of the polarization detection optical device to be measured obtained in step 4.6 is recorded as N;

[0081] Step 6: Determine whether N in step 5 is less than the preset number of decoupling data groups; if so, return to step 2, and during this round of execution, the values ​​of the nominal parameters applied to the polarization modulation unit in step 2.3 are the same as in previous rounds, the values ​​of the offsets corresponding to the applied nominal parameters are different from those in previous rounds, and the values ​​of the nominal parameters applied to the polarization modulation unit in each modulation cycle in step 3.3 are the same as in previous rounds; if not, proceed to step 7;

[0082] Step 7: During each round of execution of steps 2 to 6, the offset value corresponding to the input nominal parameter is applied to the polarization modulation unit in step 2.3, and the offset value obtained in step 2.6 is applied to the polarization modulation unit. , the one obtained in step 3.6 and the one obtained in step 4.6 The polynomial fitting is used to solve the relationship between the coupled polarization measurement error introduced by the instrument polarization and imaging quality of the polarization detection optical device to be measured, the polarization measurement error introduced by the instrument polarization and the polarization measurement error introduced by the imaging quality, and the decoupling is completed.

[0083] Furthermore, in step 6, the preset number of decoupling data groups is determined by the number of terms of the polynomial when the polynomial fitting is used to solve the problem in step 7 and the required decoupling accuracy. The value thereof is greater than or equal to the number of terms of the polynomial when the polynomial fitting is used to solve the problem in step 7. The higher the required decoupling accuracy, the larger the value.

[0084] Furthermore, the polarization modulation unit includes a phase retarder and a linear polarizer located on the optical path;

[0085] In step 2.3, the nominal parameters and corresponding offsets include: phase delay angle of the phase retarder , Phase delay angle of phase retarder Offset , linear polarizer azimuth , and the linear polarizer azimuth Offset ;

[0086] In step 3.3, the nominal parameters of the input applied in each modulation cycle include the phase delay angle of the phase retarder and the linear polarizer azimuth .

[0087] The beneficial effects of the present invention are:

[0088] (1) Based on the polarization measurement error evaluation and decoupling system of the polarization detection optical device of the present invention, according to the polarization measurement error evaluation method of the polarization detection optical device of the present invention, experiments are carried out, and the polarization measurement error introduced by the instrument polarization, the polarization measurement error introduced by the imaging quality, and the coupled polarization measurement error introduced by the instrument polarization and imaging quality of the polarization detection optical device to be measured can be obtained, and the polarization measurement errors introduced by the instrument polarization and imaging quality can be comprehensively evaluated at the same time; at the same time, based on the polarization measurement error evaluation and decoupling system of the polarization detection optical device of the present invention, according to the polarization measurement error decoupling method of the polarization detection optical device of the present invention, experiments are carried out, and the relationship between the coupled polarization measurement error introduced by the instrument polarization and imaging quality of the polarization detection optical device to be measured and the polarization measurement error introduced by the instrument polarization and imaging quality can be solved, and the coupled polarization measurement error introduced by the instrument polarization and imaging quality of the polarization detection optical device to be measured can be decoupled; therefore, the present invention solves the technical problem that the prior art lacks an evaluation method for evaluating the coupled polarization measurement error introduced by the instrument polarization and imaging quality of the polarization detection optical device, and a decoupling method for decoupling.

[0089] (2) In the present invention, based on experiments, the polarization measurement error introduced by the polarization of the polarization detection optical device to be measured, the polarization measurement error introduced by the imaging quality, and the coupled polarization measurement error introduced by the polarization of the polarization detection optical device to be measured are evaluated. Therefore, the coupled polarization measurement error introduced by the polarization of the instrument and the imaging quality is closer to the polarization measurement error actually generated when the polarization detection optical device to be measured is used for actual detection. If the coupled polarization measurement error introduced by the polarization detection optical device to be measured and obtained by the polarization measurement error evaluation method of the present invention is used as the calibration value of the polarization measurement error of the polarization detection optical device to be measured, the final detection result can be made more real and accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Figure 1 is a flow chart of an embodiment of a method for decoupling polarization measurement errors of a polarization detection optical device according to the present invention;

[0091] Figure 2 1 is a schematic diagram of the polarization measurement error evaluation and decoupling system of the polarization detection optical device of the present invention when the analysis unit is a polarization analyzer;

[0092] Figure 3 This is a schematic diagram of the system when the analysis unit selects a detector in an embodiment of the polarization measurement error evaluation and decoupling system of the polarization detection optical device of the present invention.

[0093] The descriptions of the numbers in the figure are as follows:

[0094] 1-Laser light source, 2-Beam collimator, 3-Adjustable aperture, 4-Polarizer, 5-Beam splitter, 6-Light polarization distribution modulation element, 7-Polarization modulation unit, 8-Imaging unit, 9-Polarization analyzer, 10-Information acquisition computer, 11-Optical air-floating platform, 12-Polarization detection optical device to be measured, 13-Detector. DETAILED DESCRIPTION

[0095] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0096] See also Figure 2 and Figure 3 The present invention provides a polarization measurement error evaluation and decoupling system for a polarization detection optical device. The polarization detection optical device 12 to be measured includes a polarization modulation unit 7 and an imaging unit 8 located on an optical path. Figure 2 and Figure 3 Only the case where the polarization modulation unit 7 is in front and the imaging unit 8 is in the back is shown. The imaging unit 8 can also be in front and the polarization modulation unit 7 is in the back. The polarization measurement error evaluation and decoupling system of the polarization detection optical device of the present invention includes a test beam generating module, an analysis unit and an information acquisition computer 10.

[0097] See also Figure 2 and Figure 3The test beam generating module includes a laser light source 1, a beam collimator 2, a polarizer 4, a beam splitter 5, and a light polarization distribution modulating element 6 arranged in sequence along the optical path; the beam collimator 2 is used to collimate the light beam emitted by the laser light source 1 to generate a collimated light beam; the polarizer 4 is used to convert the collimated light beam into an isotropic polarized light beam for output; the beam splitter 5 is used to reflect the isotropic polarized light beam output by the polarizer 4 to the light polarization distribution modulating element 6; the light polarization distribution modulating element 6 is used to modulate the polarization state of the incident isotropic polarized light beam to generate a light beam with the polarization state distribution required for the test; the light polarization distribution modulating element 6 can be a spatial light modulator (Spatial Light Modulator). Modulator, SLM) and other elements that can realize the modulation of the polarization distribution of the light field; the above-mentioned beam splitter 5 is also used to transmit the light beam with the polarization state distribution required for the test generated by the polarization distribution modulation element 6, so as to be incident on the polarization detection optical device 12 to be tested; in this embodiment, the above-mentioned test beam generating module preferably also includes an adjustable iris 3; the adjustable iris 3 is arranged between the beam collimator 2 and the polarizer 4; so that when the collimated light beam output by the beam collimator 2 does not match the incident light beam that can be received by the polarizer 4, the aperture size of the adjustable iris 3 can be adjusted to achieve adjustment of the light beam; in addition to being arranged between the beam collimator 2 and the polarizer 4 as in the present embodiment, the adjustable iris 3 can also be arranged at other positions in the optical path where the aperture needs to be limited. In addition to being set up according to the present embodiment, the above-mentioned beam splitter 5 can also be set up to transmit the isotropic polarized light beam output by the polarizer 4 to the polarization distribution modulation element 6 of light, and reflect the light beam with the polarization state distribution required for the test generated by the polarization distribution modulation element 6 to be incident on the polarization detection optical device 12 to be tested as a test beam. At this time, the polarization distribution modulation element 6 of light is set on the transmission light path of the beam splitter 5.

[0098] See also Figure 2 and Figure 3 The analysis unit is arranged on the output optical path of the polarization detection optical device 12 to be measured, and is used to collect the detection signal output by the polarization detection optical device 12 to be measured, and analyze the collected detection signal to extract the information required for calculating the polarization measurement error, and then transmit the extracted information required for calculating the polarization measurement error to the information collection computer 10 in real time; see Figure 2 When the polarization detection optical device polarization measurement error evaluation and decoupling system is used to evaluate the polarization measurement error of the polarization detection optical device to be measured due to the polarization of the instrument, the above-mentioned analysis unit uses the polarization analyzer 9; see Figure 3When the polarization measurement error evaluation and decoupling system of the polarization detection optical device is used to evaluate the polarization measurement error introduced by the imaging quality of the polarization detection optical device to be measured, as well as the coupled polarization measurement error introduced by the instrument polarization and imaging quality, the above-mentioned analysis unit uses the detector 13; when the analysis unit is the detector 13, the image plane of the above-mentioned imaging unit 8 and the focal plane of the detector 13 should be set to coincide with each other.

[0099] The information acquisition computer 10 is used to calculate polarization measurement errors and decouple coupled polarization measurement errors introduced by instrument polarization and imaging quality.

[0100] The polarization measurement error evaluation and decoupling system of the polarization detection optical device of this embodiment preferably further includes an optical air floating platform 11; the above-mentioned test beam generation module, analysis unit and information acquisition computer 10 are all arranged on the optical air floating platform 11, which can make the experiment more accurate.

[0101] The present invention also provides a method for evaluating polarization measurement errors of a polarization detection optical device. The polarization detection optical device 12 to be measured includes a polarization modulation unit 7 and an imaging unit 8 located on an optical path. In this embodiment, the polarization modulation unit 7 includes a phase retarder and a linear polarizer located on the optical path. The method for evaluating polarization measurement errors of a polarization detection optical device of the present invention can evaluate the polarization measurement errors of the polarization detection optical device 12 to be measured in which the polarization modulation unit 7 includes a phase retarder and a linear polarizer located on the optical path. In addition, the method for evaluating polarization measurement errors of the polarization detection optical device 12 to be measured in which the polarization modulation unit 7 of the present embodiment includes a phase retarder and a linear polarizer located on the optical path can also evaluate the polarization measurement errors of the polarization detection optical device 12 to be measured in which the polarization modulation unit 7 has other configurations. The method for evaluating polarization measurement errors of a polarization detection optical device of the present invention includes the following steps:

[0102] Step 1: Construct the polarization measurement error evaluation and decoupling system of the polarization detection optical device and determine the modulation matrix according to the polarization detection optical device 12 to be measured. ;

[0103] Step 2: See Figure 2 , the analysis unit in the evaluation and decoupling system constructed in step 1 is selected as the polarization analyzer 9, and then based on the evaluation and decoupling system, an experiment is conducted to obtain the polarization measurement error introduced by the instrument polarization of the polarization detection optical device 12 to be measured, specifically:

[0104] Step 2.1: Set the parameters of each optical element in the test beam generation module so that the test beam generation module generates a polarization state with isotropic distribution. Test beam ;

[0105] Step 2.2: Make the test beam produced in step 2.1 Incident to the polarization detection optical device 12 to be measured;

[0106] Step 2.3: Give the test beam in step 2.2 The polarization modulation unit 7 of the incident polarization detection optical device 12 to be measured applies input nominal parameters and corresponding offsets; the nominal parameters and corresponding offset types applied to the polarization modulation unit 7 are determined by the specific structure of the polarization modulation unit 7; in this embodiment, the above nominal parameters and corresponding offsets include: phase delay angle of the phase retarder , Phase delay angle of phase retarder Offset , linear polarizer azimuth , and the linear polarizer azimuth Offset ;

[0107] Step 2.4: The polarization analyzer 9 collects the optical signal output by the polarization detection optical device 12 to be measured after the input nominal parameters and the corresponding offset are applied to the polarization modulation unit 7 in step 2.3, and analyzes the collected optical signal to extract the polarization information of the optical signal. , and then extract the polarization information of the optical signal Real-time transmission to the information collection computer 10;

[0108] Step 2.5: The information acquisition computer 10 collects the polarization information of the optical signal transmitted by the polarization analyzer 9 in step 2.4. and the test beam generated in step 2.1 Polarization state The single measurement value of the polarization measurement error introduced by the polarization detection optical device 12 to be measured is calculated using the following formula: :

[0109] ;

[0110] Step 2.6: Repeat steps 2.3 to 2.5. During the repeated execution, the nominal parameters and corresponding offset values ​​applied to the polarization modulation unit 7 in step 2.3 are the same as those in the previous step. When the number of repetitions reaches the preset repetition threshold, the single measurement value of the polarization measurement error introduced by the instrument polarization of the polarization detection optical device 12 to be measured obtained by multiple calculations in step 2.5 is calculated. Average value , the average value As the obtained polarization measurement error of the polarization detection optical device 12 to be measured introduced by the instrument polarization, the system error is eliminated;

[0111] Step 3: See Figure 3, replace the polarization analyzer 9 in the evaluation and decoupling system based on step 2 with the detector 13, and then based on the evaluation and decoupling system and the modulation matrix determined in step 1 , conduct experiments to obtain the polarization measurement error introduced by the polarization detection optical device 12 to be tested due to the imaging quality, specifically:

[0112] Step 3.1: Set the parameters of each optical element in the test beam generating module so that the test beam generating module generates polarization states with different polarization distributions, i.e., polarization states with non-isotropic distributions. Test beam ;

[0113] Step 3.2: Make the image plane of the imaging unit 8 of the polarization detection optical device 12 to be tested coincide with the focal plane of the detector 13, and make the test beam generated in step 3.1 Incident to the polarization detection optical device 12 to be measured;

[0114] Step 3.3: Give the test beam in step 3.2 The incident polarization modulation unit 7 of the polarization detection optical device 12 to be measured applies input nominal parameters in each modulation period to modulate the light beam; the type of nominal parameters applied to the polarization modulation unit 7 in each modulation period is determined by the specific structure of the polarization modulation unit 7; in this embodiment, the nominal parameters applied to the input in each modulation period include the phase delay angle of the phase retarder and the linear polarizer azimuth ;

[0115] Step 3.4: Detector 13 collects test beams of different polarization modulation states under the same modulation period , after applying the input nominal parameters to each modulation cycle of the polarization modulation unit 7 in step 3.3, the output image of the polarization detection optical device 12 to be measured is analyzed, and the image intensity information of the image is extracted from it , and then extract the image intensity information of the image Real-time transmission to the information collection computer 10;

[0116] Step 3.5: The information acquisition computer 10 collects the image intensity information of the image transmitted by the detector 13 in step 3.4. , the modulation matrix determined in step 1 and the test beam generated in step 3.1 Polarization state The single measurement value of the polarization measurement error introduced by the imaging quality of the polarization detection optical device 12 to be measured is calculated using the following formula: :

[0117] ;

[0118] Where: Represents the modulation matrix The inverse matrix of

[0119] Step 3.6: Repeat steps 3.3 to 3.5. During the repeated execution, the value of the nominal parameter applied to each modulation cycle of the polarization modulation unit 7 in step 3.3 is the same as the previous one, until the number of repetitions reaches the preset repetition threshold, and the single measurement value of the polarization measurement error introduced by the imaging quality of the polarization detection optical device 12 to be measured obtained by multiple calculations in step 3.5 is calculated. Average value , the average value The polarization measurement error introduced by the imaging quality of the polarization detection optical device 12 to be measured is obtained to eliminate the systematic error;

[0120] Step 4: See Figure 3 , based on the evaluation and decoupling system based on step 3, and the modulation matrix determined in step 1 , in step 2.3, the nominal parameters and the corresponding offset values ​​are applied to the polarization modulation unit 7, and in step 3.1, the parameter values ​​of the optical elements in the test beam generation module are set, and an experiment is conducted to obtain the coupled polarization measurement error introduced by the polarization instrument and imaging quality of the polarization detection optical device 12 to be tested, specifically:

[0121] Step 4.1: According to the parameter values ​​set for each optical element in the test beam generating module in step 3.1, set the same parameters as in step 3.1 for each optical element in the test beam generating module, so that the test beam generating module generates the same test beam as in step 3.1 ;

[0122] Step 4.2: Make the image plane of the imaging unit 8 of the polarization detection optical device 12 to be tested coincide with the focal plane of the detector 13, and make the test beam generated in step 4.1 Incident to the polarization detection optical device 12 to be measured;

[0123] Step 4.3: According to the nominal parameters and corresponding offset values ​​input to the polarization modulation unit 7 in step 2.3, the test beam in step 4.2 is The polarization modulation unit 7 of the incident polarization detection optical device 12 to be measured applies input of the nominal parameters and corresponding offsets of the same parameter type and value as those in step 2.3;

[0124] Step 4.4: Detector 13 collects test beams of different polarization modulation states under the same modulation period , the image outputted by the polarization detection optical device 12 to be measured in step 4.3, and the collected image is analyzed to extract the image intensity information of the image , and then extract the image intensity information of the image Real-time transmission to the information collection computer 10;

[0125] Step 4.5: The information acquisition computer 10 collects the image intensity information of the image transmitted by the detector 13 in step 4.4. , the modulation matrix determined in step 1 and the test beam generated in step 4.1 Polarization state The single measurement value of the coupled polarization measurement error introduced by the polarization instrument and imaging quality of the polarization detection optical device 12 to be measured is calculated using the following formula: :

[0126] ;

[0127] Step 4.6: Repeat steps 4.3 to 4.5 until the number of repetitions reaches a preset repetition threshold, and calculate the single measurement value of the coupled polarization measurement error introduced by the polarization instrument and imaging quality of the polarization detection optical device 12 to be measured obtained by multiple calculations in step 4.5. Average value , the average value The evaluation is completed by obtaining the coupled polarization measurement error introduced by the polarization and imaging quality of the polarization detection optical device 12 to be measured.

[0128] The order of step 2 and step 3 in the polarization measurement error evaluation method of the polarization detection optical device of the present invention can be interchanged.

[0129] See also Figure 1The present invention also provides a method for decoupling polarization measurement errors of a polarization detection optical device, wherein the polarization detection optical device 12 to be measured includes a polarization modulation unit 7 and an imaging unit 8 located on an optical path; in this embodiment, the polarization modulation unit 7 includes a phase retarder and a linear polarizer located on the optical path; the method for decoupling polarization measurement errors of a polarization detection optical device of the present invention can not only decouple the coupled polarization measurement errors introduced by the polarization and imaging quality of the polarization detection optical device 12 to be measured in this embodiment in which the polarization modulation unit 7 includes a phase retarder and a linear polarizer located on the optical path, but can also decouple the coupled polarization measurement errors introduced by the polarization and imaging quality of the polarization detection optical device 12 to be measured in which the polarization modulation unit 7 has other configurations; steps 1 to 4 of the method for decoupling polarization measurement errors of a polarization detection optical device of the present invention are exactly the same as steps 1 to 4 of the method for evaluating polarization measurement errors of a polarization detection optical device of the present invention, and the steps of the method for decoupling polarization measurement errors of a polarization detection optical device of the present invention further include the following steps after step 4:

[0130] Step 5: The number of coupled polarization measurement errors introduced by the polarization instrument and imaging quality of the polarization detection optical device 12 to be measured obtained in step 4.6 is recorded as N;

[0131] Step 6: Determine whether the above-mentioned N in step 5 is less than the preset number of decoupling data sets; if so, return to step 2, and during the execution of this round, the value of the nominal parameter applied to the polarization modulation unit 7 in step 2.3 is the same as that in the previous rounds, the value of the offset corresponding to the applied nominal parameter is different from that in the previous rounds, and the value of the nominal parameter applied to each modulation cycle of the polarization modulation unit 7 in step 3.3 is the same as that in the previous rounds; if not, execute step 7; the above-mentioned preset number of decoupling data sets is determined by the number of terms of the polynomial when the polynomial fitting is used to solve in step 7 and the required decoupling accuracy, and its value should be greater than or equal to the number of terms of the polynomial when the polynomial fitting is used to solve in step 7. The higher the required decoupling accuracy, the larger its value; in the present invention, the relationship between the coupled polarization measurement error introduced by the polarization detection optical device 12 to be measured due to the instrument polarization and imaging quality and the polarization measurement error introduced by the instrument polarization and the polarization measurement error introduced by the imaging quality is solved by polynomial fitting, so the preset number of decoupling data sets is greater than or equal to 2;

[0132] Step 7: During each round of execution of steps 2 to 6, the value of the offset corresponding to the input nominal parameter is applied to the polarization modulation unit 7 in step 2.3, and the value obtained in step 2.6 , obtained in step 3.6 and obtained in step 4.6 The polynomial fitting is used to solve the relationship between the coupled polarization measurement error of the polarization detection optical device 12 to be measured due to the instrument polarization and imaging quality, and the polarization measurement error introduced by the instrument polarization and the polarization measurement error introduced by the imaging quality, thereby completing the decoupling.

[0133] Based on the polarization measurement error evaluation and decoupling system for polarization detection optical equipment of the present invention and according to the polarization measurement error evaluation method for polarization detection optical equipment of the present invention, a comprehensive evaluation can be performed on the polarization measurement errors introduced by the instrument polarization and imaging quality at the same time; at the same time, based on the polarization measurement error evaluation and decoupling system for polarization detection optical equipment of the present invention and according to the polarization measurement error decoupling method for polarization detection optical equipment of the present invention, decoupling of the coupled polarization measurement errors introduced by the instrument polarization and imaging quality of the polarization detection optical equipment to be measured can be achieved.

Claims

1. A polarization measurement error evaluation and decoupling system for a polarization detection optical device, wherein the polarization detection optical device (12) to be measured comprises a polarization modulation unit (7) and an imaging unit (8) located on an optical path; and is characterized in that: It includes a test beam generating module, an analysis unit and an information acquisition computer (10); The test beam generation module comprises a laser light source (1), a beam collimator (2), a polarizer (4), a beam splitter (5), and a light polarization distribution modulation element (6) arranged on the light path reflected by the beam splitter (5). The beam collimator (2) is used to collimate the light beam emitted by the laser light source (1) to generate a collimated light beam; The polarizer (4) is used to convert the collimated light beam into an isotropic polarized light beam output; The beam splitter (5) is used to reflect the isotropic polarized light beam output by the polarizer (4) to the light polarization distribution modulation element (6); The light polarization distribution modulation element (6) is used to modulate the polarization state of the incident isotropic polarized light beam to generate a light beam with a polarization state distribution required for testing; The beam splitter (5) is also used to transmit the light beam with the polarization state distribution required for the test generated by the light polarization distribution modulation element (6) so as to be incident on the polarization detection optical device (12) to be tested as a test beam; The analysis unit is arranged on the output optical path of the polarization detection optical device (12) to be measured, and is used to collect the detection signal output by the polarization detection optical device (12) to be measured, analyze the collected detection signal, extract information required for calculating the polarization measurement error, and then transmit the extracted information required for calculating the polarization measurement error to the information collection computer (10) in real time; The information acquisition computer (10) is used to calculate polarization measurement errors and decouple coupled polarization measurement errors introduced by instrument polarization and imaging quality.

2. The polarization measurement error evaluation and decoupling system for polarization detection optical equipment according to claim 1, characterized in that: Also included is an optical air-floating platform (11); The test beam generation module, the analysis unit, and the information acquisition computer (10) are all arranged on an optical air-floating platform (11).

3. The polarization measurement error evaluation and decoupling system for polarization detection optical equipment according to claim 1, characterized in that: The test beam generation module further includes an adjustable diaphragm (3); The adjustable diaphragm (3) is arranged between the beam collimator (2) and the polarizer (4).

4. The polarization measurement error evaluation and decoupling system for polarization detection optical equipment according to any one of claims 1 to 3, characterized in that: The analysis unit is a polarization analyzer (9) or a detector (13); When the analysis unit is a detector (13), the image plane of the imaging unit (8) is arranged to coincide with the focal plane of the detector (13).

5. The polarization measurement error evaluation and decoupling system for polarization detection optical equipment according to claim 4, characterized in that: The light polarization distribution modulation element (6) is a spatial light modulator.

6. A method for evaluating polarization measurement errors of a polarization detection optical device, wherein the polarization detection optical device (12) to be measured comprises a polarization modulation unit (7) and an imaging unit (8) located on an optical path; the method is characterized in that: The following steps are involved: Step 1: Construct the polarization measurement error evaluation and decoupling system of the polarization detection optical device according to claim 1, and determine the modulation matrix according to the polarization detection optical device (12) to be measured. ; Step 2: The analysis unit in the evaluation and decoupling system constructed in step 1 is selected as a polarization analyzer (9), and then based on the evaluation and decoupling system, an experiment is conducted to obtain the polarization measurement error of the polarization detection optical device (12) to be measured due to the polarization of the instrument, specifically: Step 2.1: Setting parameters of each optical element in the test beam generating module so that the test beam generating module generates a polarization state with isotropic distribution. Test beam ; Step 2.2: Make the test beam generated in step 2.1 incident on a polarization detection optical device (12) to be measured; Step 2.3: Give the test beam in step 2.2 The polarization modulation unit (7) of the incident polarization detection optical device (12) to be measured applies input nominal parameters and corresponding offsets; Step 2.4: The polarization analyzer (9) collects the optical signal output by the polarization detection optical device (12) to be measured after the input nominal parameters and the corresponding offset are applied to the polarization modulation unit (7) in step 2.3, and analyzes the collected optical signal to extract the polarization information of the optical signal. , and then extract the polarization information of the optical signal Transmitting the data to the information collection computer (10) in real time; Step 2.5: The information acquisition computer (10) collects the polarization information of the optical signal transmitted by the polarization analyzer (9) in step 2.

4. and the test beam generated in step 2.1 Polarization state , the single measurement value of the polarization measurement error introduced by the instrument polarization of the polarization detection optical device (12) to be measured is calculated using the following formula: : ； Step 2.6: Repeat steps 2.3 to 2.

5. During the repeated execution, the nominal parameters and the corresponding offset values ​​applied to the polarization modulation unit (7) in step 2.3 are the same as those in the previous time, until the number of repetitions reaches a preset repetition threshold, and the single measurement value of the polarization measurement error of the polarization detection optical device (12) to be measured due to the instrument polarization obtained by multiple calculations in step 2.5 is calculated. Average value , the average value As obtained, a polarization measurement error of the polarization detection optical device (12) to be measured is introduced by the polarization of the instrument; Step 3: Replace the polarization analyzer (9) in the evaluation and decoupling system based on step 2 with a detector (13), and then based on the evaluation and decoupling system and the modulation matrix determined in step 1 , an experiment is conducted to obtain the polarization measurement error introduced by the imaging quality of the polarization detection optical device (12) to be tested, specifically: Step 3.1: Setting parameters of each optical element in the test beam generating module so that the test beam generating module generates a polarization state with a polarization distribution difference Test beam ; Step 3.2: Make the image plane of the imaging unit (8) of the polarization detection optical device (12) to be tested coincide with the focal plane of the detector (13), and make the test beam generated in step 3.1 incident on a polarization detection optical device (12) to be measured; Step 3.3: Give the test beam in step 3.2 The polarization modulation unit (7) of the incident polarization detection optical device (12) to be measured applies input nominal parameters in each modulation period to modulate the light beam; Step 3.4: The detector (13) collects the test beams of different polarization modulation states under the same modulation period. , after applying the input nominal parameters to each modulation cycle of the polarization modulation unit (7) in step 3.3, the output image of the polarization detection optical device (12) to be measured is obtained, and the collected image is analyzed to extract the image intensity information of the image , and then extract the image intensity information of the image Transmitting the data to the information collection computer (10) in real time; Step 3.5: The information acquisition computer (10) receives the image intensity information of the image transmitted by the detector (13) in step 3.

4. , the modulation matrix determined in step 1 and the test beam generated in step 3.1 Polarization state , the single measurement value of the polarization measurement error introduced by the imaging quality of the polarization detection optical device (12) to be measured is calculated using the following formula: : ； Where: Represents the modulation matrix The inverse matrix of Step 3.6: Repeat steps 3.3 to 3.

5. During the repeated execution, the value of the nominal parameter applied to the polarization modulation unit (7) in each modulation cycle in step 3.3 is the same as the previous one, until the number of repetitions reaches a preset repetition threshold, and the single measurement value of the polarization measurement error introduced by the imaging quality of the polarization detection optical device (12) to be measured obtained by multiple calculations in step 3.5 is calculated. Average value , the average value The polarization measurement error introduced by the imaging quality of the polarization detection optical device (12) to be measured is obtained; Step 4: Based on the evaluation and decoupling system based on step 3, and the modulation matrix determined in step 1 , the nominal parameters and corresponding offset values ​​input to the polarization modulation unit (7) in step 2.3, and the parameter values ​​set for each optical element in the test beam generation module in step 3.1, are used to conduct an experiment to obtain the coupled polarization measurement error introduced by the polarization and imaging quality of the polarization detection optical device (12) to be tested, specifically: Step 4.1: According to the parameter values ​​set for each optical element in the test beam generating module in step 3.1, set the same parameters as in step 3.1 for each optical element in the test beam generating module, so that the test beam generating module generates the same test beam as in step 3.1 ; Step 4.2: Make the image plane of the imaging unit (8) of the polarization detection optical device (12) to be tested coincide with the focal plane of the detector (13), and make the test beam generated in step 4.1 incident on a polarization detection optical device (12) to be measured; Step 4.3: According to the nominal parameters and corresponding offset values ​​input to the polarization modulation unit (7) in step 2.3, the test beam in step 4.2 is The polarization modulation unit (7) of the incident polarization detection optical device (12) to be measured applies input of the nominal parameters and corresponding offsets of the same parameter type and value as those in step 2.3; Step 4.4: The detector (13) collects the test beams of different polarization modulation states under the same modulation period. , the image outputted after the polarization detection optical device (12) to be measured in step 4.3, and the collected image is analyzed to extract the image intensity information of the image , and then extract the image intensity information of the image Transmitting the data to the information collection computer (10) in real time; Step 4.5: The information acquisition computer (10) receives the image intensity information of the image transmitted by the detector (13) in step 4.

4. , the modulation matrix determined in step 1 and the test beam generated in step 4.1 Polarization state , the single measurement value of the coupled polarization measurement error introduced by the polarization instrument and imaging quality of the polarization detection optical device (12) to be measured is calculated using the following formula: : ； Step 4.6: Repeat steps 4.3 to 4.5 until the number of repetitions reaches a preset repetition threshold, and calculate the single measurement value of the coupled polarization measurement error of the polarization detection optical device (12) to be measured due to the instrument polarization and imaging quality obtained by multiple calculations in step 4.

5. Average value , the average value The coupled polarization measurement error introduced by the polarization and imaging quality of the polarization detection optical device (12) to be measured is obtained, and the evaluation is completed.

7. The method for evaluating polarization measurement errors of a polarization detection optical device according to claim 6, wherein: The polarization modulation unit (7) comprises a phase retarder and a linear polarizer located on the optical path; In step 2.3, the nominal parameters and corresponding offsets include: phase delay angle of the phase retarder , Phase delay angle of phase retarder Offset , linear polarizer azimuth , and the linear polarizer azimuth Offset ; In step 3.3, the nominal parameters of the input applied in each modulation cycle include the phase delay angle of the phase retarder and the linear polarizer azimuth .

8. A method for decoupling polarization measurement errors of a polarization detection optical device, wherein the polarization detection optical device (12) to be measured comprises a polarization modulation unit (7) and an imaging unit (8) located on an optical path; the method is characterized in that: The following steps are involved: Step 1: Construct the polarization measurement error evaluation and decoupling system of the polarization detection optical device according to claim 1, and determine the modulation matrix according to the polarization detection optical device (12) to be measured. ; Step 2: The analysis unit in the evaluation and decoupling system constructed in step 1 is selected as a polarization analyzer (9), and then based on the evaluation and decoupling system, an experiment is conducted to obtain the polarization measurement error of the polarization detection optical device (12) to be measured due to the polarization of the instrument, specifically: Step 2.1: Setting parameters of each optical element in the test beam generating module so that the test beam generating module generates a polarization state with isotropic distribution. Test beam ; Step 2.2: Make the test beam generated in step 2.1 incident on a polarization detection optical device (12) to be measured; Step 2.3: Give the test beam in step 2.2 The polarization modulation unit (7) of the incident polarization detection optical device (12) to be measured applies input nominal parameters and corresponding offsets; Step 2.4: The polarization analyzer (9) collects the optical signal output by the polarization detection optical device (12) to be measured after the input nominal parameters and the corresponding offset are applied to the polarization modulation unit (7) in step 2.3, and analyzes the collected optical signal to extract the polarization information of the optical signal. , and then extract the polarization information of the optical signal Transmitting the data to the information collection computer (10) in real time; Step 2.5: The information acquisition computer (10) collects the polarization information of the optical signal transmitted by the polarization analyzer (9) in step 2.

4. and the test beam generated in step 2.1 Polarization state , the single measurement value of the polarization measurement error introduced by the instrument polarization of the polarization detection optical device (12) to be measured is calculated using the following formula: : ； Step 2.6: Repeat steps 2.3 to 2.

5. During the repeated execution, the nominal parameters and the corresponding offset values ​​applied to the polarization modulation unit (7) in step 2.3 are the same as those in the previous time, until the number of repetitions reaches a preset repetition threshold, and the single measurement value of the polarization measurement error of the polarization detection optical device (12) to be measured due to the instrument polarization obtained by multiple calculations in step 2.5 is calculated. Average value , the average value As obtained, a polarization measurement error of the polarization detection optical device (12) to be measured is introduced by the polarization of the instrument; Step 3: Replace the polarization analyzer (9) in the evaluation and decoupling system based on step 2 with a detector (13), and then based on the evaluation and decoupling system and the modulation matrix determined in step 1 , an experiment is conducted to obtain the polarization measurement error introduced by the imaging quality of the polarization detection optical device (12) to be tested, specifically: Step 3.1: Setting parameters of each optical element in the test beam generating module so that the test beam generating module generates a polarization state with a polarization distribution difference Test beam ; Step 3.2: Make the image plane of the imaging unit (8) of the polarization detection optical device (12) to be tested coincide with the focal plane of the detector (13), and make the test beam generated in step 3.1 incident on a polarization detection optical device (12) to be measured; Step 3.3: Give the test beam in step 3.2 The polarization modulation unit (7) of the incident polarization detection optical device (12) to be measured applies input nominal parameters in each modulation period to modulate the light beam; Step 3.4: The detector (13) collects the test beams of different polarization modulation states under the same modulation period. , after applying the input nominal parameters to each modulation cycle of the polarization modulation unit (7) in step 3.3, the output image of the polarization detection optical device (12) to be measured is obtained, and the collected image is analyzed to extract the image intensity information of the image , and then extract the image intensity information of the image Transmitting the data to the information collection computer (10) in real time; Step 3.5: The information acquisition computer (10) receives the image intensity information of the image transmitted by the detector (13) in step 3.

4. , the modulation matrix determined in step 1 and the test beam generated in step 3.1 Polarization state , the single measurement value of the polarization measurement error introduced by the imaging quality of the polarization detection optical device (12) to be measured is calculated using the following formula: : ； Where: Represents the modulation matrix The inverse matrix of Step 3.6: Repeat steps 3.3 to 3.

5. During the repeated execution, the value of the nominal parameter applied to the polarization modulation unit (7) in each modulation cycle in step 3.3 is the same as the previous one, until the number of repetitions reaches a preset repetition threshold, and the single measurement value of the polarization measurement error introduced by the imaging quality of the polarization detection optical device (12) to be measured obtained by multiple calculations in step 3.5 is calculated. Average value , the average value The polarization measurement error introduced by the imaging quality of the polarization detection optical device (12) to be measured is obtained; Step 4: Based on the evaluation and decoupling system based on step 3, and the modulation matrix determined in step 1 , the nominal parameters and corresponding offset values ​​input to the polarization modulation unit (7) in step 2.3, and the parameter values ​​set for each optical element in the test beam generation module in step 3.1, are used to conduct an experiment to obtain the coupled polarization measurement error introduced by the polarization and imaging quality of the polarization detection optical device (12) to be tested, specifically: Step 4.1: According to the parameter values ​​set for each optical element in the test beam generating module in step 3.1, set the same parameters as in step 3.1 for each optical element in the test beam generating module, so that the test beam generating module generates the same test beam as in step 3.1 ; Step 4.2: Make the image plane of the imaging unit (8) of the polarization detection optical device (12) to be tested coincide with the focal plane of the detector (13), and make the test beam generated in step 4.1 incident on a polarization detection optical device (12) to be measured; Step 4.3: According to the nominal parameters and corresponding offset values ​​input to the polarization modulation unit (7) in step 2.3, the test beam in step 4.2 is The polarization modulation unit (7) of the incident polarization detection optical device (12) to be measured applies input of the nominal parameters and corresponding offsets of the same parameter type and value as those in step 2.3; Step 4.4: The detector (13) collects the test beams of different polarization modulation states under the same modulation period. , the image outputted after the polarization detection optical device (12) to be measured in step 4.3, and the collected image is analyzed to extract the image intensity information of the image , and then extract the image intensity information of the image Transmitting the data to the information collection computer (10) in real time; Step 4.5: The information acquisition computer (10) receives the image intensity information of the image transmitted by the detector (13) in step 4.

4. , the modulation matrix determined in step 1 and the test beam generated in step 4.1 Polarization state , the single measurement value of the coupled polarization measurement error introduced by the polarization instrument and imaging quality of the polarization detection optical device (12) to be measured is calculated using the following formula: : ； Step 4.6: Repeat steps 4.3 to 4.5 until the number of repetitions reaches a preset repetition threshold, and calculate the single measurement value of the coupled polarization measurement error of the polarization detection optical device (12) to be measured due to the instrument polarization and imaging quality obtained by multiple calculations in step 4.

5. Average value , the average value The coupled polarization measurement error introduced by the polarization and imaging quality of the polarization detection optical device (12) to be measured is obtained; Step 5: The number of coupled polarization measurement errors introduced by the polarization detection optical device (12) to be measured due to the instrument polarization and imaging quality obtained in step 4.6 is recorded as N; Step 6: Determine whether N in step 5 is less than the preset number of decoupling data groups; if so, return to step 2, and during the execution of this round, the value of the nominal parameter applied to the polarization modulation unit (7) in step 2.3 is the same as that of the previous rounds, the value of the offset corresponding to the applied nominal parameter is different from that of the previous rounds, and the value of the nominal parameter applied to each modulation cycle of the polarization modulation unit (7) in step 3.3 is the same as that of the previous rounds; if not, execute step 7; Step 7: During the execution of steps 2 to 6 in each round, the value of the offset corresponding to the nominal parameter input in step 2.3 is applied to the polarization modulation unit (7), and the value of the offset obtained in step 2.6 is applied to the polarization modulation unit (7). , the one obtained in step 3.6 and the one obtained in step 4.6 , polynomial fitting is used to solve the relationship between the coupled polarization measurement error of the polarization detection optical device (12) to be measured due to the instrument polarization and imaging quality, and the polarization measurement error introduced by the instrument polarization and the polarization measurement error introduced by the imaging quality, thereby completing decoupling.

9. The method for decoupling polarization measurement errors of a polarization detection optical device according to claim 8, characterized in that: In step 6, the preset number of decoupling data groups is determined by the number of terms of the polynomial when the polynomial fitting is used to solve the problem in step 7 and the required decoupling accuracy. The value is greater than or equal to the number of terms of the polynomial when the polynomial fitting is used to solve the problem in step 7. The higher the required decoupling accuracy, the larger the value.

10. The polarization measurement error decoupling method of a polarization detection optical device according to claim 9, characterized in that: The polarization modulation unit (7) comprises a phase retarder and a linear polarizer located on the optical path; In step 2.3, the nominal parameters and corresponding offsets include: phase delay angle of the phase retarder , Phase delay angle of phase retarder Offset , linear polarizer azimuth , and the linear polarizer azimuth Offset ; In step 3.3, the nominal parameters of the input applied in each modulation cycle include the phase delay angle of the phase retarder and the linear polarizer azimuth .

Images