A measurement system and method of transmission and absorbance spectra matrices

Abstract

The application discloses a kind of transmission spectrum matrix and absorbance spectrum matrix measurement system, including along optical path successively arranged infrared light source, collimating lens, interference system, polarizing system, sample bin, polarimeter system, lens, detector and computer processing system;Interference system includes beam splitter, fixed mirror and moving mirror;Wherein beam splitter is cubic component, and the face of its circumferential four faces and collimating lens is face A, from face A along clockwise direction, it is face B, face C and face D in sequence;Fixed mirror is arranged at face B;Moving mirror is arranged at face C;Polarizing system is arranged at face D, including along optical path successively arranged polarizer and extinction ratio 1 / 4 wave plate;Polarimeter system includes along optical path successively arranged extinction ratio 1 / 4 wave plate and polarizer;Computer processing system is used to acquire polarization information and calculate to obtain transmission spectrum matrix and absorbance spectrum matrix.The application also discloses a kind of transmission spectrum matrix and absorbance spectrum matrix measurement system measurement method.

Description

Technical Field

[0001] This invention belongs to the field of spectral detection instrument technology, and relates to a measurement system and method for transmission spectrum matrix and absorbance spectrum matrix. Background Technology

[0002] Transmittance refers to the ratio of luminous flux transmitted to incident luminous flux; it indicates the intensity of light radiation energy transmitted by an object. Spectral transmittance refers to the transmittance of monochromatic light of a specific wavelength. Absorbance is a method of measuring how much light a substance absorbs by measuring the intensity of light passing through a sample solution. Its basic principle is that every compound can absorb or transmit light within a certain wavelength range. This measurement method can also be used to measure the amount of known chemical substances. With the development of science, the contribution of spectroscopy is becoming increasingly significant, and the application of spectroscopy and spectral analysis in various fields is becoming more and more widespread, such as the detection of material composition, the detection of crop diseases and pests, and the detection of material quality. Absorbance is one of the most commonly used quantitative analysis methods in chemistry, physics, biochemistry, materials chemistry engineering, and clinical applications. These are mainly achieved by analyzing the absorption or transmission spectra of substances; therefore, measuring transmittance and absorbance is of great significance, indicating that accurately measuring the T(k) transmission spectrum matrix and A(k) absorbance spectrum matrix of an unknown sample is crucial in materials analysis.

[0003] Stokes vector (S0, S1, S2, S3) T (The superscript T represents transpose) As a one-dimensional vector, the polarization state of light is described. According to the invention patent application number 202111181474.7, a set of one-dimensional Stokes vectors can be obtained by adding a polarizer accessory to a traditional Fourier transform infrared spectrometer and then measuring according to the proposed six-step method. However, since both the T(k) transmission spectrum matrix and the A(k) absorbance spectrum matrix are 4×4 matrices, four sets of linearly independent Stokes vectors are needed to recover them. Currently, the aforementioned patent and existing technologies cannot obtain four sets of linearly independent Stokes vectors, thus affecting the analysis and application of related technologies. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems and deficiencies of the prior art and provide a measurement system and method for transmission spectrum matrix and absorbance spectrum matrix. The measurement system of this invention can recover the T(k) (transmission spectrum) and A(k) (absorbance spectrum) spectral matrices containing all polarization optical characteristic information.

[0005] To achieve the above objectives, the technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0006] A measurement system for transmission spectrum matrix and absorbance spectrum matrix includes an infrared light source 1, a collimating lens 2, an interferometric system, a sample chamber 6, a lens 7, and a detector 8 arranged sequentially at intervals. The system is characterized by a polarizing system for modulating the infrared light source before it is incident on the sample, arranged at intervals between the interferometric system and the sample chamber 6; and an analyzing system for modulating the emitted infrared light source, arranged at intervals between the sample chamber 6 and the lens 7. The detector 8 is connected to a computer processing system via a data cable. The interferometric system includes a beam splitter 3, a fixed mirror 4, and a movable mirror 5. The beam splitter 3 is a cubic component, with surface A facing the collimating lens 2 along its four circumferential faces. From surface A, in a clockwise direction, the faces are B, C, and D, respectively. The fixed mirror 4 is arranged parallel to each other at a distance from surface B, and the movable mirror 5 is arranged parallel to each other at a distance from surface C.

[0007] In a further preferred embodiment, the polarization system consists of a polarizer-11 and an achromatic quarter-wave plate-12 arranged sequentially at intervals, wherein the polarizer-11 is arranged facing each other at intervals with the beam splitter 3 surface D, and the achromatic quarter-wave plate-12 is arranged facing each other at intervals with the sample chamber 6.

[0008] In a further preferred embodiment, the polarization detection system consists of a second achromatic quarter-wave plate 10 and a second polarizer 9 arranged sequentially at intervals, wherein the second achromatic quarter-wave plate 10 is arranged facing the sample chamber 6 at intervals, and the second polarizer 9 is arranged facing the lens 7 at intervals.

[0009] In a further preferred embodiment, the distance between the fixed mirrors 4 placed parallel to each other at the distance plane B is 10cm to 15cm.

[0010] In a further preferred embodiment, the distance between the moving mirrors 5 placed parallel to each other at the distance plane C is 10cm to 15cm.

[0011] In a further preferred embodiment, the polarizer 11 and the polarizer 9 are provided with an outer frame rotation bracket, and the outer frame rotation bracket is provided with a rotation angle scale mark.

[0012] In a further preferred embodiment, the computer processing system has the function of recovering the Stokes vector from the interferometric data and calculating the transmission spectrum matrix T(k) and the absorbance spectrum matrix A(k).

[0013] In a further preferred embodiment, both polarizer 11 and polarizer 9 are Soleber thin-film polarizers WP25M-UB; both achromatic quarter-wave plate 12 and achromatic quarter-wave plate 10 are Retarder.

[0014] In a further preferred embodiment, the sample chamber 6 is provided with a sample platform for holding solid and liquid samples. On the two walls of the sample chamber 6 that are perpendicular to the optical path, there are circular holes with a diameter of 4 to 7 cm that are coaxial with the optical path.

[0015] Further optimization of the scheme: In the experiment, except for the achromatic 1 / 4 waveplate which cannot be replaced by other types of waveplates, all others can be replaced. However, changing the experimental instruments will affect the accuracy of the experimental results. In addition, the wavelength range of the final result is the intersection of the wavelength ranges of all instruments.

[0016] A measurement method for a transmission spectrum matrix and absorbance spectrum matrix measurement system, the specific measurement steps of which are as follows:

[0017] Step 1: Arrange the infrared light source 1, collimating lens 2, interference system, sample chamber 6, lens 7, and detector 8 along the optical path; wherein the infrared light source 1 and collimating lens 2 are parallel and facing each other with a distance of 5cm; the beam splitter 3 has its surface A parallel and facing each other with a distance of 8cm from the collimating lens 2, the fixed mirror 4 is arranged parallel and facing each other at a distance of 10cm from surface B, the movable mirror 5 is arranged parallel and facing each other at a distance of 10cm from surface C, and the sample chamber 6, lens 7, and detector 8 are placed sequentially with a distance of 15cm facing each other at surface D; connect detector 8 to the computer system; turn on the infrared light source 1, and prepare measurement data after the infrared light source 1 stabilizes.

[0018] Step 2: Place polarizer 2 (9) parallel to each other at a distance of 10 cm from sample chamber 6. Adjust polarizer 2 (9) sequentially to 0°, 45°, 90°, and 135° respectively, obtaining unmodulated background interference data, denoted as follows:

[0019] Step 3: Place achromatic quarter-wave plate 10 parallel to each other between sample chamber 6 and polarizer 2 9. Adjust polarizer 2 9 to 45° and 135° sequentially, obtaining unmodulated background interference data, denoted as follows:

[0020] Step 4: Place polarizer 11 parallel to each other at a distance of 5 cm from surface D of the beam splitter, and adjust polarizer 11 to 0°; remove achromatic quarter-wave plate 10; sequentially adjust polarizer 9 to 0°, 45°, 90°, and 135° respectively, and record the background interference data modulated at 0° as follows.

[0021] Step 5: Place achromatic quarter-wave plate 10 parallel to each other between sample chamber 6 and polarizer 9. Adjust polarizer 9 to 45° and 135° sequentially, obtaining background interference data at 0° modulation, denoted as follows:

[0022] Step 6: Adjust polarizer 11 to 45°; remove achromatic quarter-wave plate 10; sequentially adjust polarizer 29 to 0°, 45°, 90°, and 135° respectively, obtaining the background interference data modulated at 45°, denoted as follows.

[0023] Step 7: Place achromatic quarter-wave plate 10 parallel to each other between sample chamber 6 and polarizer 2 9. Adjust polarizer 2 9 to 45° and 135° sequentially, obtaining background interference data modulated at 45°, denoted as follows:

[0024] Step 8: Place achromatic quarter-wave plate 12 parallel to each other between polarizer 11 and sample chamber 6; remove achromatic quarter-wave plate 10; sequentially adjust polarizer 9 to 0°, 45°, 90°, and 135°, respectively, and record the background interference data of the modulated circular polarization as follows.

[0025] Step 9: Place achromatic quarter-wave plate 10 parallel to each other between sample chamber 6 and polarizer 2 9. Adjust polarizer 2 9 to 45° and 135° sequentially, obtaining the background interference data of the modulated circularly polarized plate, denoted as follows:

[0026] Step 10: Place the sample to be tested in sample chamber 6, and repeat steps 2 to 9 to measure four sets of sample interference data, which are recorded as the unmodulated sample interference data. and Modulation of sample interferometric data at 0° Modulated sample interference data at 45° Modulated circularly deflected sample interference data

[0027] Step 11: Process the 48 interferometric data points obtained in the above steps using a computer processing system. Use formula (1) to process the obtained interferometric data I... (m,n) (δ) is converted into spectral data B (m,n) (k).

[0028]

[0029] Step 12: Use formula (2) to convert each group of 6 spectral data into 4 Stokes vectors containing all polarization spectral information.

[0030]

[0031] Step 13: Use formula (3) to calculate T(k) from the obtained Stokes vector.

[0032]

[0033]

[0034] Step 14: Use formula (4) to further process the T(k) matrix to obtain A(k).

[0035]

[0036] The absorbance spectrum matrix of A(k) is obtained.

[0037] Because there is too much data to measure, the data will be divided into categories to differentiate them. Identifier; δ represents optical path difference; I(δ) represents interference data; k represents wavenumber; B(k) represents spectral data; N is the number of data sets, ordered by Greek letters (I, II, III, IV); in represents the collected background data, out represents the collected sample data; m represents the scale of the polarizer (12) rotation; n represents whether an extinction ratio 1 / 4 waveplate is placed, n is represented as π / 2 when an achromatic 1 / 4 waveplate is placed, and n is represented as 0 when an achromatic 1 / 4 waveplate is not placed; T ij (k) and A ij In (k), ij represents the position in the matrix.

[0038] According to the method of transforming interference data into spectral information in formula (1) above, namely inverse Fourier transform, the Stokes vector is obtained using the spectral information, and finally the T(k) transmission spectrum matrix and A(k) absorbance spectrum matrix are recovered. The 16 transmission spectra obtained are independent of each other; the 16 absorbance spectra are also independent of each other. However, from the overall measurement results, the 16 transmission spectra and the 16 absorbance spectra are correlated. Together, they characterize all the polarization optical properties of the sample being measured, providing a basis for analyzing the molecular structure of the object.

[0039] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0040] This invention modulates the infrared light source before it is incident on the sample, enabling the measurement of four different Stokes vectors of the incident light and four different Stokes vectors of the outgoing light after passing through the sample. Then, using the eight different Stokes vectors measured, the transmission spectrum matrix and absorbance spectrum matrix of the unknown sample in all directions can be measured and calculated through an improved measurement system.

[0041] The transmission spectrum matrix and absorbance spectrum matrix measurement system and method of the present invention obtain more comprehensive and accurate information, and can ensure that the information is not repeated or omitted. It solves the problems and defects of the prior art (such as the invention patent with application number 202111181474.7) that can only measure one set of Stokes vectors, obtain single information, unclear information, and missing information. Attached Figure Description

[0042] Figure 1 Schematic diagram of the measurement system for the transmission spectrum matrix and absorbance spectrum matrix;

[0043] Figure 2 A schematic diagram of the basic structure of the measurement system for the transmission spectrum matrix and absorbance spectrum matrix;

[0044] Figure 3 Schematic diagram of the construction of a modulation-free measurement system (1);

[0045] Figure 4 Schematic diagram of the construction of the modulation-free measurement system (2);

[0046] Figure 5 Schematic diagram of the construction of the 0° and 45° modulation measurement system (1);

[0047] Figure 6 Schematic diagram of the construction of the 0° and 45° modulation measurement system (2);

[0048] Figure 7 Schematic diagram of the modulated circular deflection measurement system (1);

[0049] Figure 8 Schematic diagram of the modulated circular deflection measurement system (2);

[0050] Figure 9 Flowchart of modulation-free measurement steps;

[0051] Figure 10 Flowchart of the measurement and data processing scheme for the transmission spectrum matrix and absorbance spectrum matrix measurement system;

[0052] Figure 11 Six unmodulated background interferograms;

[0053] Figure 12 Six unmodulated background spectra;

[0054] Figure 13 Four Stokes images with no modulated background;

[0055] Figure 14 Schematic diagram of the T(k) transmission spectrum matrix;

[0056] Figure 15 A(k) absorbance spectrum matrix diagram. Detailed Implementation

[0057] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings.

[0058] like Figure 1 As shown, this is a measurement system for the transmission spectrum matrix and absorbance spectrum matrix of the present invention, which consists of an infrared light source 1, a collimating lens 2, an interference system (beam splitter 3, fixed mirror 4, moving mirror 5), a polarization system (polarizer 11, achromatic quarter wave plate 12), a sample chamber 6, a polarization analysis system (achromatic quarter wave plate 10, polarizer 9), a lens 7, a detector 8, and a computer processing system. The infrared light source 1, collimating lens 2, and beam splitter 3 are arranged in parallel intervals from left to right. The infrared light source 1 and collimating lens 2 are parallel and face each other, spaced 5cm apart. The beam splitter 3 is a cube; the face facing the collimating lens 2 along its circumference is called face A, and face A is spaced 8cm apart from the collimating lens 2. From face A, in a clockwise direction, they are successively called face B, face C, and face D. The fixed mirror 4 is arranged parallel to face B at a distance of 10cm; the movable mirror 5 is arranged parallel to face C at a distance of 10cm; and the beam splitter 3 is arranged in parallel to face D at a distance of 15cm. The sample chamber 6, lens 7, and detector 8 are arranged. The detector 8 is connected to a computer via a data cable for signal export. The polarization system includes a polarizer 11 and an achromatic quarter-wave plate 12 placed sequentially and 5 cm apart between the beam splitter surface D and the sample chamber 6. The polarization analyzer system includes an extinction ratio quarter-wave plate 10 and a polarizer 9 placed sequentially and 5 cm apart between the sample chamber 6 and the lens 8. The computer processing system has the function of interferometric data recovery of Stokes vector and calculation of transmission spectrum matrix T(k) and absorbance spectrum A(k) matrix.

[0059] After the infrared light source 1 is stabilized, the sample to be tested can be processed. If the sample is solid, it needs to be pressed into a solid sample; if it is liquid, it needs to be loaded into a liquid tank. After the sample is prepared, it is placed in the sample chamber 6 when sample data needs to be measured. It should be noted that since this method measures a large amount of data, the volatility of the sample needs to be considered, therefore, it is necessary to ensure that the sample used for each set of data is basically consistent.

[0060] There must be sufficient space between the surface D of the beam splitter 3 and the sample chamber 6 to place the components required to modulate the infrared light source before it is incident on the sample; similarly, there must also be sufficient space between the sample chamber 6 and the lens 7 to place the components required by the system; try to ensure that the center heights of the polarizer 11, the achromatic quarter-wave plate 12, the container for placing the sample, the circular holes on both sides of the sample chamber, the achromatic quarter-wave plate 10, and the polarizer 9 are at the same level; the polarizer 11 of the polarization system must be placed in front of the achromatic quarter-wave plate 12, and the achromatic quarter-wave plate 10 of the analyzer system must be placed in front of the polarizer 9, and the order of the two cannot be reversed.

[0061] The polarizer 11 and polarizer 29 are provided with an outer frame rotation bracket, and the outer frame rotation bracket is provided with a rotation angle scale mark.

[0062] The polarizer 11 and the polarizer 9 are both Sorebo thin-film polarizers WP25M-UB; the achromatic quarter-wave plate 12 and the achromatic quarter-wave plate 10 are both Retarder.

[0063] The sample chamber 6 is equipped with a sample platform for holding solid and liquid samples. On the two walls of the sample chamber 6 that are perpendicular to the optical path, there are circular holes with a diameter of 5 cm that are coaxial with the optical path.

[0064] Reference Figure 9 , Figure 10 As shown, combined with Figures 2 to 8 The present invention discloses a measurement method for a transmission spectrum matrix and absorbance spectrum matrix measurement system, the specific measurement steps of which include:

[0065] Before the first measurement, according to Figure 2 The measurement system is constructed as shown. An infrared light source 1, collimating lens 2, interference system, sample chamber 6, lens 7, and detector 8 are arranged along the optical path. The infrared light source 1 and collimating lens 2 are parallel and face each other, spaced 5 cm apart. The beam splitter 3 has its surface A parallel and face each other, spaced 8 cm apart. The fixed mirror 4 is placed parallel and face each other at a distance of 10 cm from surface B. The movable mirror 5 is placed parallel and face each other at a distance of 10 cm from surface C. The sample chamber 6, lens 7, and detector 8 are placed sequentially at a distance of 15 cm from each other at surface D. The detector 8 is connected to the computer system. The infrared light source 1 is turned on, and measurement data is prepared after the infrared light source 1 stabilizes.

[0066] During the first measurement, polarizers 2 and 9 were placed facing each other at a distance of 10 cm parallel to the sample chamber. Figure 3 As shown; then, polarizer 29 was adjusted to 0°, 45°, 90°, and 135° in sequence, respectively, and the unmodulated background interference data were obtained and denoted as follows.

[0067] During the second measurement, an achromatic quarter-wave plate 10 was placed 5 cm parallel to each other between sample chamber 6 and polarizer 9. Figure 4 As shown; polarizer 29 was adjusted to 45° and 135° in sequence, respectively, and the unmodulated background interference data were obtained and denoted as follows.

[0068] For the third measurement, polarizer 11 was placed parallel to each other and facing each other at a distance of 5 cm from surface D of the beam splitter, and polarizer 11 was adjusted to 0°; the achromatic quarter-wave plate 10 was removed, as shown... Figure 5 As shown; polarizer 29 was sequentially adjusted to 0°, 45°, 90°, and 135°, respectively, and the background interference data obtained at 0° modulation were denoted as follows.

[0069] For the fourth measurement, an achromatic quarter-wave plate 10 was placed 5 cm parallel to each other between sample chamber 6 and polarizer 9. Figure 6 As shown, polarizer 29 was sequentially adjusted to 45° and 135° respectively, and the background interference data obtained at 0° modulation were denoted as follows.

[0070] For the fifth measurement, the polarizer 11 was adjusted to 45°; the achromatic quarter-wave plate 10 was removed, as shown... Figure 5 As shown; polarizer 29 was sequentially adjusted to 0°, 45°, 90°, and 135°, respectively, and the background interference data modulated at 45° was obtained and denoted as follows.

[0071] For the sixth measurement, an achromatic quarter-wave plate 10 was placed 5 cm parallel to each other between sample chamber 6 and polarizer 9. Figure 6 As shown, polarizer 29 was sequentially adjusted to 45° and 135° respectively, and the background interference data obtained at 45° modulation were denoted as follows.

[0072] For the seventh measurement, achromatic quarter-wave plate 12 was placed parallel to each other between polarizer 11 and sample chamber 6; achromatic quarter-wave plate 10 was removed, as shown below. Figure 7 As shown; polarizer 29 was adjusted to 0°, 45°, 90°, and 135° in sequence, and the background interference data of the modulated circular polarization were obtained respectively, denoted as...

[0073] For the eighth measurement, an achromatic quarter-wave plate 10 was placed parallel to each other between sample chamber 6 and polarizer 9, as follows: Figure 8As shown; polarizer 29 was adjusted to 45° and 135° in sequence, and the background interference data of the modulated circular polarization were obtained respectively, denoted as follows.

[0074] In the ninth measurement, the sample to be tested was placed in sample chamber 6, and the previous eight measurements were repeated to obtain four sets of sample interference data, which were recorded as the unmodulated sample interference data. and Modulation of sample interferometric data at 0° Modulated sample interference data at 45° Modulated circularly deflected sample interference data

[0075] Measurement results as follows Figure 11 As shown, there are six unmodulated background interferograms; among them, Figure (1) is denoted as The background interference pattern is shown as unmodulated and polarizer 9 is adjusted to 0°; Figure (2) is denoted as The background interference pattern is shown as unmodulated and with polarizer 9 adjusted to 45°; Figure (3) is denoted as The background interference pattern is shown in Figure (4) with no modulation, polarizer 9 adjusted to 45° and achromatic 1 / 4 wave plate 10 added; The background interference pattern is shown as unmodulated and with polarizer 9 adjusted to 90°; Figure (5) is denoted as The background interference pattern is shown as unmodulated and with polarizer 9 adjusted to 135°; Figure (6) is denoted as The background interference pattern is shown as unmodulated, with polarizer 9 adjusted to 135° and achromatic 1 / 4 waveplate 10 added;

[0076] The 48 interferograms obtained from the above measurements were processed by a computer processing system; the obtained interferometric data I was processed according to formula (1). (m,n) (δ) is converted into spectral data B (m,n) (k);

[0077]

[0078] like Figure 12 As shown, there are six unmodulated background spectra after interferogram conversion; where Figure (1) is denoted as The background spectrum is shown as unmodulated and with polarizer 9 adjusted to 0°; Figure (2) is denoted as The background spectrum is shown as unmodulated with polarizer 9 adjusted to 45°; Figure (3) is denoted as The background spectrum is shown in Figure (4) with no modulation, polarizer 9 adjusted to 45° and achromatic 1 / 4 waveplate 10 added; The background spectrum is shown as unmodulated with polarizer 9 adjusted to 90°; Figure (5) is denoted as The background interference pattern is shown as unmodulated and with polarizer 9 adjusted to 135°; Figure (6) is denoted as The background spectrum is shown with no modulation, polarizer 9 adjusted to 135° and achromatic 1 / 4 waveplate 10 added;

[0079] Then, using formula (2), each group of 6 spectral data is converted into 4 Stokes vectors containing all polarization spectral information;

[0080]

[0081] like Figure 13 The image shown is a set of four Stokes images with no modulated background after conversion; where image (1) is denoted as The Stokes plot is represented by the unmodulated background S0(k); Figure (2) is denoted as The Stokes plot is represented by the unmodulated background S1(k); Figure (3) is denoted as The Stokes plot is represented by the unmodulated background S2(k); Figure (4) is denoted as The Stokes plot is represented as S4(k) with no modulation background;

[0082] T(k) is obtained by calculating the Stokes vector using formula (3);

[0083]

[0084] like Figure 14 This represents 16 schematic diagrams of the transmission spectrum matrix; among which Figure (1)T 00 (k) The transmittance of the incident light wave to the sample after passing through it, as shown in Figure (2)T 12 (k), Figure (3)T 13 (k), Figure (4)T 14 (k) represents the attenuation characteristics of the beam, as shown in Figure (5)T. 21 (k), Figure (9)T 31 (k), Figure (13)T 41 (k) describes the polarization capability for incident unpolarized light, while the other nine figures represent the depolarization and phase delay capabilities of the beam.

[0085] A(k) is obtained by further processing the T(k) matrix using formula (4);

[0086]

[0087] like Figure 15 This represents a schematic diagram of 16 absorbance spectra in the absorbance spectral matrix; among which Figure (1)A 00 (k) The absorption capacity of the sample after the incident light wave passes through it, as shown in Figure (2)A. 12 (k), Figure (3)A 13 (k), Figure (4)A 14 (k) represents the degree of absorption of the light beam, as shown in Figure (5)A. 21 (k), Figure (9)A 31 (k), Figure (13)A 41 (k) describes the polarization capability for incident unpolarized light, while the other nine figures represent the depolarization and phase delay capabilities of the beam.

[0088] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection claimed in the claims of the present invention.

Claims

1. A method for measuring a transmission spectrum matrix and an absorbance spectrum matrix, characterized in that, The steps are as follows: Step 1: Arrange the infrared light source (1), collimating lens (2), interference system, sample chamber (6), lens (7), and detector (8) along the optical path; wherein the infrared light source (1) and collimating lens (2) are parallel to each other and 5cm apart; the surface A of the beam splitter (3) is parallel to the collimating lens (2) and 8cm apart; a fixed mirror (4) is arranged parallel to each other at a distance of 10cm from surface B; a moving mirror (5) is arranged parallel to each other at a distance of 10cm from surface C; and the sample chamber (6), lens (7), and detector (8) are arranged sequentially at a distance of 15cm from each other at surface D; connect the detector (8) to the computer system; turn on the infrared light source (1), and prepare the measurement data after the infrared light source (1) stabilizes; Step 2: Place polarizer 2 (9) parallel to each other at a distance of 10cm from the sample chamber (6), and adjust polarizer 2 (9) to 0°, 45°, 90° and 135° in sequence to measure the unmodulated background interference data. Step 3: Place achromatic 1 / 4 wave plate 2 (10) in parallel and facing each other between sample chamber (6) and polarizer 2 (9), and adjust polarizer 2 (9) to 45° and 135° respectively in sequence to measure the unmodulated background interference data; Step 4: Place polarizer 1 (11) parallel to each other at a distance of 5cm from surface D of beam splitter (3), and adjust polarizer 1 (11) to 0°; remove achromatic 1 / 4 wave plate 2 (10); adjust polarizer 2 (9) to 0°, 45°, 90° and 135° in sequence to measure the background interference data modulated at 0°; Step 5: Place achromatic 1 / 4 wave plate 2 (10) in parallel and facing each other between sample chamber (6) and polarizer 2 (9), and adjust polarizer 2 (9) to 45° and 135° respectively in sequence to measure the background interference data modulated at 0°. Step 6: Adjust polarizer one (11) to 45°; remove achromatic 1 / 4 wave plate two (10); adjust polarizer two (9) to 0°, 45°, 90° and 135° in sequence to measure the background interference data modulated at 45°; Step 7: Place achromatic 1 / 4 wave plate 2 (10) in parallel and facing each other between sample chamber (6) and polarizer 2 (9), and adjust polarizer 2 (9) to 45° and 135° respectively in sequence to measure the background interference data modulated at 45°; Step 8: Place a 1 / 4 wave plate (12) parallel to each other between polarizer one (11) and sample chamber (6); remove a 1 / 4 wave plate two (10); adjust polarizer two (9) to 0°, 45°, 90° and 135° in sequence to measure the background interference data of the modulated circular polarization. Step 9: Place achromatic 1 / 4 wave plate 2 (10) parallel to each other between sample chamber (6) and polarizer 2 (9), and adjust polarizer 2 (9) to 45° and 135° respectively in sequence to measure the background interference data of the modulated circular polarization; Step 10: Place the sample to be tested in the sample chamber (6), and repeat steps two to eight to measure four sets of sample interference data; Step 11: Process the 48 interferograms obtained in the above steps using a computer processing system; process the obtained interferometric data according to formula (1). Convert to spectral data ; （1） Step 12: Use formula (2) to convert each group of 6 spectral data into 4 Stokes vectors containing all polarization spectral information; （2） Step 13: Calculate the obtained Stokes vector using formula (3). ; （3） Step 14: Use formula (4) to... Further information processing of the matrix yields ; （4）。 2. A measurement system for implementing the measurement method of the transmission spectrum matrix and absorbance spectrum matrix as described in claim 1, comprising an infrared light source (1), a collimating lens (2), an interference system, a sample chamber (6), a lens (7), and a detector (8) arranged sequentially at intervals, characterized in that, A polarizing system for modulating an infrared light source before it is incident on the sample is disposed between the interference system and the sample chamber (6); a polarizing analyzer for modulating an outgoing infrared light source is disposed between the sample chamber (6) and the lens (7); the detector (8) is connected to a computer processing system via a data cable; the interference system includes a beam splitter (3), a fixed mirror (4) and a movable mirror (5), wherein the beam splitter (3) is a cubic component, and the face facing the collimating lens (2) among its four circumferential faces is face A, and from face A in a clockwise direction, they are face B, face C and face D in sequence; the fixed mirror (4) is disposed parallel to each other at a distance from face B, and the movable mirror (5) is disposed parallel to each other at a distance from face C. The polarization system consists of a polarizer (11) and an achromatic quarter-wave plate (12) arranged at intervals in sequence. The polarizer (11) is arranged at intervals facing the surface D of the beam splitter (3), and the achromatic quarter-wave plate (12) is arranged at intervals facing the sample chamber (6). The polarization detection system consists of a second achromatic quarter wave plate (10) and a second polarizer (9) arranged in sequence at intervals, wherein the second achromatic quarter wave plate (10) is arranged facing the sample chamber (6) at intervals, and the second polarizer (9) is arranged facing the lens (7) at intervals. The computer processing system is capable of recovering the Stokes vector from interferometric data and calculating the transmission spectrum matrix. and absorbance spectrum Matrix function processing system; The computer processing system performs signal processing; the obtained interference data is processed according to formula (1). Convert to spectral data ; （1） Using formula (2), each group of 6 spectral data is converted into 4 Stokes vectors containing all polarization spectral information; （2） The Stokes vector is obtained by using formula (3). ; （3） Using formula (4) Further information processing of the matrix yields ; （4）。 3. The measurement system according to claim 2, characterized in that, The distance between the fixed mirrors (4) placed parallel to each other at the distance plane B is 10cm to 15cm.

4. The measurement system according to claim 2, characterized in that, The distance between the moving mirrors (5) placed parallel to each other at the distance plane C is 10cm to 15cm.

5. The measurement system according to claim 2, characterized in that, The polarizer one (11) and polarizer two (9) are provided with an outer frame rotation frame, and the outer frame rotation frame is provided with a rotation angle scale mark.

6. The measurement system according to claim 2, characterized in that, The polarizer one (11) and the polarizer two (9) are both Sorebo thin-film polarizers WP25M-UB; the achromatic quarter-wave plate one (12) and the achromatic quarter-wave plate two (10) are both Retarder.

7. The measurement system according to claim 2, characterized in that, The sample chamber (6) is equipped with a sample platform for holding solid and liquid samples. On the two walls of the sample chamber (6) that are perpendicular to the optical path, there are circular holes with a diameter of 4 to 7 cm that are coaxial with the optical path.

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