System for measuring enantiomeric excess percentage of chiral compound based on vector structured light field

Abstract

The invention discloses a system for measuring the enantiomer excess percentage of a chiral compound based on a vector structured light field. The system comprises a laser, a lens, a half-wave plate, a quarter-wave plate, a light beam shifter, a spatial light modulator, a polaroid, a sample, a beam splitter prism, a CCD camera, a polarization camera and a computer. A first light field can be obtained after laser beam expanding and beam splitting through a light beam shifter and orthogonal component loading opposite phase coherence superposition, and a second light field is obtained after the first light field passes through a uniform and non-uniform S-type enantiomer and R-type enantiomer mixture sample. The polarization camera and the CCD are controlled by a computer to obtain five polarization components at the same time, and spatial polarization state distribution and intermode phase distribution at different moments are reconstructed by using a Stokes polarization method. Polarization state rotation angles at different moments are obtained through comparison with the initial moment, and ee values at different positions in the space can be obtained through the relation between the rotation angles and the enantiomer excess percentage ee.

Description

Technical Field

[0001] The invention relates to the technical field of vector light field regulation and measurement of the enantiomeric excess percentage of a chiral compound, and in particular to a system for measuring the enantiomeric excess percentage of a chiral compound based on a vector structured light field. Background Art

[0002] The development of lasers is now receiving more and more attention. In recent years, vector light fields with spatially inhomogeneous polarization states have been widely studied because their multiple degrees of freedom (including amplitude, phase, polarization and wavelength) can be controlled separately and have unique spatial polarization distributions. They have become a powerful tool to promote progress in optics and other fields. Complex vector light beams can be regarded as the classical entanglement between spatial degrees of freedom and polarization degrees of freedom. This unique property is used in optical metrology, high-precision measurement and optical communications. Importantly, the new effects exhibited by vector light beams in the process of light-matter interaction have injected vitality into applications such as light capture, super-resolution imaging and optical information processing.

[0003] Chiral compounds play an important role in the chemical, biological, medical and food industries, where the ability to distinguish enantiomers and measure enantiomeric excess (ee) is crucial. Traditional ee detection methods mainly rely on scalar beams with a single, uniform distribution of polarization states in the cross section, which limits their sensitivity and spatial resolution and is only applicable to homogeneous chiral materials. Innovative methods are required in complex mixtures or heterogeneous chiral solutions, such as advanced optical techniques with enhanced spatial and polarization sensitivity. Summary of the invention

[0004] In order to overcome the defects in the above-mentioned prior art, the present invention provides a system for measuring the enantiomeric excess percentage of chiral compounds based on vector structured light fields. It is a new method for measuring the enantiomeric excess percentage (ee) by using the cross-sectional spatial variation polarization distribution unique to vector light beams. The Stokes polarization method is used to perform spatially resolved polarization state analysis, so that the polarization characteristics of the light beam can be reconstructed before and after interacting with the chiral medium. The spatial evolution of the polarization state at each position on the cross section caused by the vector light field passing through different degrees of non-uniform chiral solutions is used, and the Stokes polarization method is used to spatially resolve the specific polarization state changes and phase changes. A direct correspondence between the change in polarization state distribution and the potential enantiomeric excess percentage (ee) is established, and the ee at different lateral positions of the light beam can be extracted. This method can achieve a spatial resolution of micrometers.

[0005] Technical Solution

[0006] A system for measuring the enantiomeric excess percentage of a chiral compound based on a vector structured light field comprises a laser (A), a lens (B1, B2), a half-wave plate (C1, C2, C3), a beam shifter (D1, D2), a spatial light modulator (E), a quarter-wave plate (F1, F2), a sample (G), a beam splitter (H), a polarizer (I), a CCD camera (J), a polarization camera (K) and a computer (M); wherein the lens (B1) and the lens (B2) expand the light beam, the half-wave plate (C1) is used to adjust the polarization direction of the incident light beam to 45 degrees, and two horizontally polarized light beams and vertically polarized light beams are emitted after passing through the beam shifter (D1), one of which is converted into horizontal linear polarization through the half-wave plate (C2) so as to be modulated by a spatial light modulator (E); the two beams are respectively incident on the spatial light modulator (E), and the spatial light modulator (E) is loaded with and The digital hologram is respectively modulated by the output half-wave plate (C3) to convert the vertical polarization into horizontal polarization again. The two orthogonal Laguerre-Gaussian modes carrying opposite phases are combined into a radially distributed vector light field, i.e., the first light field, through the beam shifter (D2); the first light field is incident on the sample (G), is split by the beam splitter prism (H), passes through the quarter-wave plate (F2) and the polarizer (I) to reach the CCD camera (J), and reaches the polarization camera (K) to obtain the light intensity map. The CCD camera (J) and the polarization camera (K) upload the collected data to the computer (L) for data processing.

[0007] Furthermore, the generated first light field expression is shown in the following formula 1:

[0008]

[0009] in and They represent the unit vectors of right-handed and left-handed circular polarization components respectively, and the phase difference between the two orthogonal components is e iδ ; The two orthogonal components are Laguerre-Gaussian beams and The radially polarized vector beam is coherently superimposed on each other to generate a radially polarized vector beam; the superscript 1 and -1 of LG indicate that the topological charge is 1, and the subscript 0 indicates that the number of rings distributed along the radial direction is 0; the radially polarized vector beam exhibits a symmetrical radial polarization distribution as the first light field; the first light field The mode represents the phase variation along the angular direction in the form of

[0010] Furthermore, the sample (H) is a chiral compound solution, preferably S-(+)-limonene is used as the S enantiomer, with a specific rotation value of -120; preferably R-(+)-limonene is used as the R enantiomer, with a specific rotation value of +120; the container for holding the sample (H) is made of glass or acrylic material; by continuously dripping the R enantiomer from the upper left corner area of ​​the sample, i.e., the second quadrant area of ​​the xy plane, into the S enantiomer solution, a mixture of enantiomers with different proportions and unevenness is prepared.

[0011] Further, the following steps are included:

[0012] Step 1, the first light field is vertically incident on the sample (H);

[0013] Step 2, the radial vector light field interacts with the sample (H), and the emitted light field is the second light field;

[0014] Step 3, the CCD camera (J) and the polarization camera (K) simultaneously capture different polarization components of the second light field and transmit them to the computer (M) for reconstruction of polarization state distribution and phase;

[0015] Step 4: CCD camera (J) captures the light intensity image I of the left-handed circularly polarized component of the second light field. R The polarization camera (K) captures the light intensity diagram I of the horizontal, vertical, diagonal and anti-diagonal polarization components of the second light field H ,I V ,I D ,I A ;

[0016] Step 5, using the Stokes polarization method to perform spatial polarization state analysis, using four light intensity measurement values ​​to calculate, respectively S0 = I H +I V , S1=I H -I V , S2=I D +I A , S3=2I R -S0;

[0017] Step 6, through △φ 0 =arctan(S2 / S1) / 2 to obtain the inter-mode phase. After the first light field passes through the second light field of the sample (H), the polarization state distribution and inter-mode phase distribution at time t0-t5 are reconstructed.

[0018] Furthermore, the enantiomeric excess (ee) is the excess of one enantiomer over the other enantiomer in a mixture of enantiomers, which is the ratio of the difference in the concentrations of the two enantiomers to the sum of their concentrations, as shown in the following formula 2:

[0019]

[0020] Among them C R represents the concentration of the R enantiomer, C S It represents the concentration of S enantiomer.

[0021] Furthermore, the relationship between concentration and optical rotation θ is established using the optical rotation formula θ = [α]·L·C, where L represents the path length of light through the solution, [α] represents the specific optical rotation of the enantiomer, and C R Represents the concentration of the R enantiomer; the specific rotation values ​​of the enantiomers are equal in magnitude and opposite in sign.

[0022] Furthermore, the enantiomeric excess percentage can be directly related to the measured rotation angle θ using the optical rotation formula, as shown in the following formula 3:

[0023]

[0024] The optical rotation θ 1 Corresponding to the R enantiomer, θ 2 represents the optical rotation of the S enantiomer. 1 The sign is positive, θ 2 The sign is negative: θ 1 and θ 2 The greater the absolute value difference between them, the smaller the absolute value of the enantiomeric excess percentage. A positive ee value indicates that the R type accounts for a higher proportion, and a negative ee value indicates that the S type accounts for a higher proportion. 8. A system for measuring the enantiomeric excess percentage of a chiral compound based on a vector structured light field according to claim 3, characterized in that: the polarization state distribution of the first light field after passing through a pure R-type enantiomer is obtained; the polarization state distribution after passing through a pure R-type enantiomer is corrected to a radial polarization distribution through phase compensation, which is used as the reference value of the polarization state distribution, and this time is t0.

[0025] Furthermore, when the two enantiomers are not completely mixed, five polarization component light intensity images are taken at four different time periods, corresponding to the moments t1-t4; the R and S enantiomers are allowed to mix evenly by standing to form a uniform mixture of equal amounts of enantiomers, and five polarization component light intensity images of the uniform mixture are taken and recorded as the moment t5.

[0026] Furthermore, after the first light field passes through the second light field of the enantiomer mixture, the polarization state distribution at time t1-t5 is subtracted from the reference value of the polarization state distribution at time t0, and the rotation angle of each spatial position can be obtained. The ee value at time t1-t5 is calculated through the quantitative relationship between the rotation angle and the ee value.

[0027] Beneficial Effects

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] Compared with conventional scalar light techniques, our approach shows significant advantages in sensitivity, spatial resolution, and adaptability to spatially varying chiral detection. The robustness and accuracy of our approach are experimentally verified by passing a vector light field through heterogeneous and homogeneous mixtures of R- and S-enantiomers. The high agreement between the experimental results and standard reference values ​​emphasizes the versatility and effectiveness of our approach. By exploiting the rich transverse polarization structure of vector beams, this work provides a powerful and practical tool for high-resolution chiral sensing. This technique has significant application potential in areas ranging from monitoring chiral synthesis processes to quantifying the concentrations of organic compounds in atmospheric and environmental studies, with broader implications for fields such as biomedical diagnostics and optical sensing. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the structure of a system for measuring the enantiomeric excess percentage of a chiral compound based on a vector structured light field according to the present invention;

[0031] Figure 2 is the light intensity and polarization state distribution of the second light field at different times (t0-t5) after the first light field passes through the sample;

[0032] Figure 3 is the spatial phase distribution of the second light field at different times (t0-t5) after the first light field passes through the sample;

[0033] Figure 4 The spatial polarization states of the second light field at different times (t1-t5) after the first light field passes through the sample are respectively relative to the polarization state at time t0, and the three-dimensional diagram gives the polarization rotation angle at each position;

[0034] Figure 5 It is the average ee value of different quadrants of the entire xy cross section at different times (t0-t5) of the second light field after the first light field passes through the sample.

[0035] Reference numerals

[0036] Laser (A), lenses (B1, B2), half-wave plates (C1, C2, C3), beam shifters (D1, D2), spatial light modulator (E), quarter-wave plates (F1, F2), sample (G), beam splitter (H), polarizer (I), CCD camera (J), polarization camera (K) and computer (M). DETAILED DESCRIPTION

[0037] In order to better illustrate the content of the present invention, the following is a detailed description with reference to the accompanying drawings and implementation examples:

[0038] like Figure 1As shown, a system for measuring the enantiomeric excess percentage of a chiral compound based on a vector structured light field is characterized by comprising a laser (A), a lens (B1, B2), a half-wave plate (C1, C2, C3), a beam shifter (D1, D2), a spatial light modulator (E), a quarter-wave plate (F1, F2), a sample (G), a beam splitter (H), a polarizer (I), a CCD camera (J), a polarization camera (K) and a computer (M);

[0039] Furthermore, a lens (B1) with a small focal length and a lens (B2) with a large focal length form a beam expansion system to expand the laser output beam;

[0040] Furthermore, the main axis direction of the half-wave plate (C1) is set at an angle of 22.5° to the horizontal, and the polarization state direction is converted to a diagonal direction;

[0041] Furthermore, the diagonally polarized light beam passes through a beam shifter (D1) to emit two beams of horizontal and vertical polarization;

[0042] Further, one of the paths is converted into horizontal linear polarization through a half-wave plate (C2) so as to be modulated by a spatial light modulator (E), and the two paths are incident on the spatial light modulator (E) respectively;

[0043] Furthermore, the spatial light modulator (E) is loaded with and Digital holograms;

[0044] Furthermore, the light passing through the half-wave plate (C2) is modulated by the spatial light modulator (E) and then emitted by the half-wave plate (C3) to convert the vertical polarization into horizontal polarization again;

[0045] Furthermore, two orthogonal Laguerre-Gaussian modes with opposite phases are combined and coherently superimposed through a beam shifter (D2) to generate a radially distributed vector light field, i.e., a first light field. The generated first light field expression is shown in the following formula 1:

[0046]

[0047] in and They represent the unit vectors of right-handed and left-handed circular polarization components respectively, and the phase difference between the two orthogonal components is e iδ The two orthogonal components are low-order Laguerre-Gaussian beams and The coherent superposition produces a typical radially polarized vector beam. The superscript 1 and -1 of LG indicate that the topological charge is 1, and the subscript 0 indicates that the number of rings distributed along the radial direction is 0. The beam exhibits a symmetrical radial polarization distribution as the first light field.

[0048] Furthermore, the first light field The mode represents the phase variation along the angular direction in the form of Wherein l and p can be selected as any integer, and this patent only gives the special case of l=1, p=0.

[0049] Furthermore, the first light field is incident on the sample (G), and the two interact with each other and then emerge;

[0050] Furthermore, the sample (H) is a chiral compound solution. In this experiment, S-(+)-limonene is used as the S enantiomer with a specific rotation value of -120, and R-(+)-limonene is used as the R enantiomer with a specific rotation value of +120.

[0051] Furthermore, the material properties of the container for holding the sample (H) need to satisfy good light transmittance, such as glass or acrylic box.

[0052] Furthermore, the first light field needs to be vertically incident on the sample (H).

[0053] Furthermore, the light field emitted after the radial vector light field interacts with the sample (H) is the second light field.

[0054] Furthermore, the second light field is split by a beam splitter prism (H), passes through a quarter wave plate (F2) and a polarizer (I) to reach a CCD camera (J), and reaches a polarization camera (K) to obtain a light intensity map;

[0055] Furthermore, the CCD camera (J) captures the light intensity image I of the left-handed circularly polarized component. R .

[0056] Furthermore, the polarization camera (K) captures the light intensity images I of the horizontal, vertical, diagonal and anti-diagonal polarization components. H ,I V ,I D ,I A .

[0057] Furthermore, the Stokes polarization method is used to analyze the spatial polarization state, and the four light intensity measurement values ​​S0, S1, S2 and S3 are used to calculate: S0 = I H +I V , S1=I H -I V , S2=I D +I A , S3=2I R -S0.

[0058] Furthermore, the inter-mode phase can be expressed by ∆φ 0 =arctan(S2 / S1) / 2 to obtain.

[0059] Furthermore, enantiomeric excess (ee) is the excess of one enantiomer over the other in a mixture of enantiomers and can be defined as the ratio of the difference in the concentrations of the two enantiomers to the sum of their concentrations, where C R represents the concentration of the R enantiomer, C S Expressing the concentration of the S enantiomer:

[0060]

[0061] Furthermore, the relationship between concentration and optical rotation θ is established using the optical rotation formula θ = [α]·L·C, where L represents the path length of light through the solution, [α] represents the specific optical rotation of the enantiomer, and C R Represents the concentration of the R enantiomer.

[0062] Furthermore, the specific rotation values ​​of a pair of enantiomers are equal in magnitude and opposite in sign.

[0063] Furthermore, the enantiomeric excess is directly related to the measured rotation angle θ. 1 Corresponding to the R enantiomer, θ 2 represents the optical rotation of the S enantiomer. 1 The sign is positive, θ 2 The sign is negative:

[0064]

[0065] Furthermore, θ 1 and θ 2 The greater the absolute value difference between them, the smaller the absolute value of the enantiomeric excess percentage. A positive ee value indicates that the R type accounts for a higher proportion, and a negative value indicates that the S type accounts for a higher proportion.

[0066] Furthermore, the polarization state distribution of the first light field after passing through the pure R-type antipodes is obtained.

[0067] Furthermore, through phase compensation, the polarization state distribution after passing through the pure R-type enantiomer is corrected to a radial polarization distribution, which is used as a reference value of the polarization state distribution. This time is t0.

[0068] Furthermore, by continuously dropping the R enantiomer from the upper left corner area of ​​the sample, i.e., the second quadrant area of ​​the xy plane, into the S enantiomer solution, a heterogeneous enantiomeric mixture with different proportions was prepared.

[0069] Furthermore, five polarization component intensity images are taken at four different time periods, corresponding to t1-t4.

[0070] Furthermore, the R and S enantiomers are allowed to mix evenly by standing to form a uniform mixture of equal amounts of enantiomers.

[0071] Furthermore, the intensity graphs of the five polarization components of the homogeneous mixture are taken and recorded as the time t5.

[0072] Furthermore, after the first light field passes through the second light field of the sample (H), the polarization state distribution at time t0-t5 is reconstructed respectively, and the polarization state distribution at different times is used Figure 2 express.

[0073] Furthermore, after the first light field passes through the second light field of the sample (H), the inter-mode phase distribution at time t0-t5 is obtained respectively, and the phase distribution at different times is used Figure 3 express.

[0074] Furthermore, after dropping different volumes of the mixture of the R-type enantiomer into the pure S-type enantiomer sample, the spatial polarization state distribution of the second light field is obtained. Taking the polarization state distribution of the pure S-type enantiomer at time t0 as the reference, the spatial polarization state distribution at time t1-t5 is subtracted from the spatial polarization state distribution at time t0 to obtain the rotation angle of the second light field at each spatial position. The rotation angle is expressed as Figure 4 To express.

[0075] Furthermore, after the first light field passes through the second light field after the enantiomer mixture, Figure 4 The rotation angle of each spatial position at time t0-t5 can be calculated by the formula. In order to reduce the error, we divide it into four quadrants, and the average value of ee in each quadrant is Figure 5 Given in.

[0076] Specifically, the sample at time t0 is a uniform solution of pure S-enantiomer, such as Figure 2 , 3 The polarization state and phase distribution of is shown in the first picture. Its distribution is symmetrical. Figure 4 The deflection angle in indicates that this moment is taken as the reference value. Figure 5 The ee value in indicates that the purity of the S-enantiomer solution is close to 100% at this moment. During the period from t1 to t4, the two enantiomers in the mixture are not mixed to uniformity. Figure 2 and Figure 3 The polarization state and phase distribution are not symmetrically distributed. Figure 4 The polarization state rotation angle in the image can also be intuitively seen that the rotation angle of the dripping side is greater than that of the other side, and through Figure 5 The ee value distribution at the corresponding time in the figure also shows that the ee value on the dripping side decreases faster, indicating that the proportion of the S-type enantiomer in this area is higher than that on the other side. At time t5, it shows that the two enantiomers are gradually mixed evenly, their polarization state distribution and phase distribution become symmetrical again, and the rotation angle of the spatial position tends to be the same, and the ee value of each different quadrant gradually approaches.

[0077] This system demonstrates that we can use vector light fields to measure ee values ​​at different positions in a dynamic chiral system in real time, and this method has a certain degree of accuracy.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the technical solutions of the present invention have been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system for measuring the enantiomeric excess percentage of chiral compounds based on vector structured light field, characterized in that: The invention comprises a laser (A), a lens (B1, B2), a half-wave plate (C1, C2, C3), a beam shifter (D1, D2), a spatial light modulator (E), a quarter-wave plate (F1, F2), a sample (G), a beam splitter (H), a polarizer (I), a CCD camera (J), a polarization camera (K) and a computer (M); wherein the lens (B1) and the lens (B2) are used to expand the light beam, the half-wave plate (C1) is used to adjust the polarization direction of the incident light beam to 45°, and two light beams, horizontal and vertical polarization, are emitted after passing through the beam shifter (D1), one of which is converted into horizontal linear polarization through the half-wave plate (C2) for modulation by the spatial light modulator (E); the two beams are respectively incident on the spatial light modulator (E), and the spatial light modulator (E) is loaded with and The digital hologram is respectively modulated by the output half-wave plate (C3) to convert the vertical polarization into horizontal polarization again. The two orthogonal Laguerre-Gaussian modes carrying opposite phases are combined into a radially distributed vector light field, i.e., the first light field, through the beam shifter (D2); the first light field is incident on the sample (G), is split by the beam splitter prism (H), passes through the quarter-wave plate (F2) and the polarizer (I) to reach the CCD camera (J), and reaches the polarization camera (K) to obtain the light intensity map. The CCD camera (J) and the polarization camera (K) upload the collected data to the computer (L) for data processing.

2. The system for measuring the enantiomeric excess percentage of a chiral compound based on a vector structured light field according to claim 1, characterized in that: The generated first light field expression is shown in the following formula: in and They represent the unit vectors of right-handed and left-handed circular polarization components respectively, and the phase difference between the two orthogonal components is e iδ ; The two orthogonal components are Laguerre-Gaussian beams and The radially polarized vector beam is coherently superimposed on each other to generate a radially polarized vector beam; the superscript 1 and -1 of LG indicate that the topological charge is 1, and the subscript 0 indicates that the number of rings distributed along the radial direction is 0; the radially polarized vector beam exhibits a symmetrical radial polarization distribution as the first light field; the first light field The mode represents the phase variation along the angular direction in the form of 3. The system for measuring the enantiomeric excess percentage of a chiral compound based on a vector structured light field according to claim 1, characterized in that: The sample (H) is a chiral compound solution, preferably S-(+)-limonene is used as the S enantiomer, and the specific rotation value is -120; preferably R-(+)-limonene is used as the R enantiomer, and the specific rotation value is +120; the container for holding the sample (H) is made of glass or acrylic material; by continuously dripping the R enantiomer from the upper left corner area of ​​the sample, that is, the second quadrant area of ​​the xy plane, into the S enantiomer solution, a non-uniform enantiomer mixture of different proportions is prepared.

4. A system for measuring enantiomeric excess percentage of chiral compounds based on vector structured light field according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1, the first light field is vertically incident on the sample (H); Step 2, the radial vector light field interacts with the sample (H), and the emitted light field is the second light field; Step 3, the CCD camera (J) and the polarization camera (K) simultaneously capture different polarization components of the second light field and transmit them to the computer (M) for reconstruction of polarization state distribution and phase; Step 4: CCD camera (J) captures the light intensity image I of the left-handed circularly polarized component of the second light field. R The polarization camera (K) captures the light intensity diagram I of the horizontal, vertical, diagonal and anti-diagonal polarization components of the second light field H ,I V ,I D ,I A ; Step 5, using the Stokes polarization method to perform spatial polarization state analysis, using four light intensity measurement values ​​to calculate, respectively S0 = I H +I V , S1=I H -I V , S2=I D +I A , S3=2I R -S0; Step 6, obtain the inter-mode phase through △φ0=arctan(S2 / S1) / 2, and reconstruct the polarization state distribution and inter-mode phase distribution at time t0-t5 after the first light field passes through the second light field of the sample (H).

5. A system for measuring enantiomeric excess percentage of chiral compounds based on vector structured light field according to any one of claims 1 to 4, characterized in that: Enantiomeric excess (ee) is the excess of one enantiomer over the other in a mixture of enantiomers and is the ratio of the difference in the concentrations of the two enantiomers to the sum of their concentrations, as shown in the following formula: Among them C R represents the concentration of the R enantiomer, C S It represents the concentration of S enantiomer.

6. The system for measuring the enantiomeric excess percentage of a chiral compound based on a vector structured light field according to claim 5, characterized in that: The relationship between concentration and optical rotation θ is established using the optical rotation formula θ = [α]·L·C, where L represents the path length of light through the solution, [α] represents the specific optical rotation of the enantiomer, and C R Represents the concentration of the R enantiomer; the specific rotation values ​​of the enantiomers are equal in magnitude and opposite in sign.

7. The system for measuring the enantiomeric excess percentage of a chiral compound based on a vector structured light field according to claim 6, characterized in that: The percent enantiomeric excess can be directly related to the measured rotation angle θ using the optical rotation formula, as shown below, The optical rotation θ1 corresponds to the R enantiomer, and θ2 represents the optical rotation of the S enantiomer. The sign of θ1 is positive, and the sign of θ2 is negative: the greater the difference in absolute values ​​between θ1 and θ2, the smaller the absolute value of the enantiomeric excess percentage. A positive ee value indicates a higher proportion of the R type, and a negative value indicates a higher proportion of the S type.

8. The system for measuring the enantiomeric excess percentage of a chiral compound based on a vector structured light field according to claim 3, characterized in that: The polarization state distribution of the first light field after passing through the pure R-type antipode is obtained; the polarization state distribution after passing through the pure R-type antipode is corrected to radial polarization distribution through phase compensation, which is used as a reference value of the polarization state distribution. This time is t0.

9. The system for measuring the enantiomeric excess percentage of a chiral compound based on a vector structured light field according to claim 3, characterized in that: When the two enantiomers are not completely mixed, the five polarization component light intensity images are taken at four different time periods, corresponding to the moments t1-t4; the R and S enantiomers are allowed to mix evenly by standing to form a uniform mixture of equal enantiomers, and the five polarization component light intensity images of the uniform mixture are taken and recorded as the moment t5.

10. The system for measuring the enantiomeric excess percentage of a chiral compound based on a vector structured light field according to claim 9, characterized in that: After the first light field passes through the second light field of the enantiomer mixture, the polarization state distribution at time t1-t5 is subtracted from the reference value of the polarization state distribution at time t0 to obtain the rotation angle of each spatial position, and the ee value at time t1-t5 is calculated through the quantitative relationship between the rotation angle and the ee value.

Images