Method and device for measuring concurrency of vector light beams based on single speckle space correlation

Abstract

The invention relates to a method and device for measuring the concurrency of vector light beams based on single speckle spatial correlation, and the method comprises the steps: scattering a to-be-measured vector light beam into a spatial incoherent light field, converting the spatial incoherent light field into a partially coherent light field through Fourier transform, collecting an original speckle intensity distribution map in the central region of a Fourier transform plane, and calculating the concurrency of the vector light beam; the method comprises the following steps of: performing background correction and spatial self-correlation operation on the optical concurrency to obtain a normalized spatial correlation distribution diagram, reading a zero displacement point value as a correlation value, calculating the concurrency according to a linear relation between the correlation value and the optical concurrency, and comprising rotary frosted glass, a lens, an image sensor and a calculation module. The concurrency degree can be output in real time only through single-time speckle shooting and single-point correlation reading, the system complexity is remarkably reduced through linear optical device combination, high precision and high robustness are kept in turbulent flow and other complex medium environments, and an efficient measurement scheme is provided for optical communication and other dynamic scenes.

Description

Technical Field

[0001] This invention relates to the field of optical measurement technology, and in particular to a method and apparatus for measuring the concurrency of a vector beam based on single speckle spatial correlation. Background Technology

[0002] Vector beams, due to their unique coupling characteristics between polarization and spatial degrees of freedom, have become an indispensable tool in modern optics. Thanks to their inseparable degrees of freedom, this vector field is considered a quantum-like state (but not a quantum state and without non-local correlations), similar to a locally entangled state, enabling it to encode high-dimensional information and generate complex field gradients, thus achieving breakthroughs in fields such as optical trapping, super-resolution microscopy, and quantum-inspired communication protocols.

[0003] In recent years, optical concurrency, as an emerging degree of freedom for vector beams, has attracted extensive research both domestically and internationally. This index quantifies the degree of inseparability between the beam's polarization mode and spatial mode, with a value ranging from 0 (pure scalar light) to 1 (pure vector light). In the field of structured light, defects in optical devices, alignment errors, and disturbances such as turbulent air, underwater environments, and optical fibers can lead to amplitude and phase distortions in the spatial mode of the optical field. Studies have found that the polarization non-uniformity of vector beams is immune to all unitary perturbations.

[0004] Due to the excellent properties of vector degrees, numerous studies have been conducted on the measurement of optical concurrency. Although polarization and spatial modes are coupled, existing measurement methods still focus on independently handling these degrees of freedom. For example, a great deal of work has been done on determining the spatial mode composition of a beam, such as mode interferometry, phase retrieval algorithms, and digital holographic mode decomposition; the beam polarization state is usually measured by Stokes polarization determination, which can calculate the polarization azimuth and ellipticity at various points on the beam.

[0005] However, effective methods for measuring the overall "vector characteristics" of the light field are still lacking. Existing techniques involve introducing a quantum toolbox to perform state tomography reconstruction of entangled photon pairs using synchronous, identically-attributed, separate projection measurements. A complete state tomography requires 36 measurements (6 polarization projections × 6 spatial mode projections). This is a point-to-point scanning measurement process, unable to achieve real-time, dynamic measurement, and only yields an averaged, potentially degraded result. Further research has shown that a substrate-independent Stokes parametric measurement method can effectively handle complex turbulent environments; however, to ensure real-time performance and synchronization, the experimental setup requires beam splitting, increasing the complexity and difficulty of the experimental equipment. Another existing technique involves constructing an atomic state interferometer to imprint the spatially varying polarization characteristics of the vector beam onto atomic spin polarization, thus establishing a direct link between optical spatial-polarization correlation and atomic state interference. However, its stringent experimental conditions result in low repeatability, making it difficult to apply to fundamental measurements. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the problems of poor environmental adaptability, high system complexity, insufficient real-time performance and limited measurement accuracy in the prior art when measuring the optical concurrency of vector beams.

[0007] To address the aforementioned technical problems, this invention provides a method for measuring vector beam concurrency based on single-shot speckle spatial correlation, comprising the following steps: S1: Scatter the vector beam to be measured into a spatially incoherent light field; transform the incoherent light field into a partially coherent light field after Fourier transform; collect the original speckle intensity distribution map of the partially coherent light field in the central region of the Fourier transform plane; S2: Perform background correction on the original speckle intensity distribution map to obtain an optimized speckle intensity distribution map. Then, perform spatial self-correlation operation on the optimized speckle intensity distribution map according to the spatial correlation function to obtain a normalized spatial correlation distribution map. Read the value of the zero displacement point in the normalized spatial correlation distribution map as the correlation value. S3: Calculate the optical concurrency of the vector beam based on the preset linear relationship between the correlation value and the optical concurrency.

[0008] In one embodiment of the present invention, the method for background correction of the original speckle intensity distribution map in step S2 is as follows: symmetrically cropping a square sub-image of the central region from the original speckle intensity distribution map, acquiring a dark field noise map under the same exposure conditions, and performing a pixel-by-pixel subtraction operation between the square sub-image and the dark field noise map to obtain the optimized speckle intensity distribution map.

[0009] In one embodiment of the present invention, in step S3, the preset linear relationship between the correlation value and the optical concurrency is expressed by the following formula: , in, For optical concurrency, For associated values, .

[0010] Based on the same inventive concept, the present invention also provides a device for measuring the concurrency of a vector beam based on single-shot speckle spatial correlation, comprising: Rotating frosted glass is used to scatter the incident vector beam of the test object into a spatially incoherent light field; A lens is used to convert the incoherent spatial light field into a partially coherent light field after Fourier transform. An image sensor, whose photosensitive surface is in close contact with the rear glass surface of the lens along the direction of the incident vector beam to be measured, is used to acquire the original speckle intensity distribution map of a partially coherent light field. The calculation module is used to perform background correction on the original speckle intensity distribution map to obtain an optimized speckle intensity distribution map; perform spatial self-correlation operation to generate a normalized spatial correlation distribution map, and read the value of the zero displacement point in the normalized spatial correlation distribution map as the correlation value; and calculate the optical concurrency of the vector beam according to the preset linear relationship between the correlation value and the optical concurrency.

[0011] In one embodiment of the present invention, the lens is positioned at a distance of one focal length from the rotating frosted glass.

[0012] In one embodiment of the present invention, the frosted glass rotates at a low speed, and its rotation period T is related to the exposure time of the image sensor. satisfy .

[0013] In one embodiment of the present invention, the photosensitive surface of the image sensor is in close contact with the rear glass surface of the lens along the direction of the incident vector beam to be measured, and the center of the photosensitive surface of the image sensor coincides with the optical axis of the lens; the image sensor acquires the original speckle intensity distribution map within a single exposure cycle.

[0014] In one embodiment of the present invention, the image sensor is a CMOS sensor or a CCD sensor.

[0015] The present invention also provides an electronic device comprising a processor, a memory, and a bus system, wherein the processor and the memory are connected via the bus system, the memory is used to store instructions, and the processor is used to execute the instructions stored in the memory to implement the method for measuring vector beam concurrency based on single speckle spatial correlation.

[0016] The present invention also provides a computer storage medium storing a computer software product, the computer software product including several instructions for causing a computer device to execute the method for measuring vector beam concurrency based on single speckle spatial correlation.

[0017] The technical solution of the present invention has the following advantages compared with the prior art: This invention generates a partially coherent light field through scattering and Fourier transform optical paths. After a single acquisition of a speckle pattern at the center of the Fourier plane, noise is eliminated, and zero displacement point values ​​are extracted through spatial self-correlation operations. Concurrency is directly calculated based on a linear mapping relationship. This reduces measurement errors in complex media environments such as turbulence and biological tissues, while achieving real-time measurement and improving light energy utilization. It provides a measurement paradigm with high precision, high real-time performance, and strong environmental adaptability for vector beam applications in dynamic and complex scenarios such as quantum communication and live-body microscopy. Attached Figure Description

[0018] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings: Figure 1 This is a flowchart illustrating a method for measuring vector beam concurrency based on single-shot speckle spatial correlation, provided in an embodiment of the present invention. Figure 2 This is a schematic diagram illustrating the operating principle of a device for measuring the concurrency of a vector beam based on single-shot speckle spatial correlation, provided in an embodiment of the present invention. Explanation of reference numerals in the accompanying drawings: 1. Rotating frosted glass; 2. Lens; 3. Image sensor; 4. Calculation module; 5. Original speckle intensity distribution map; 6. Normalized spatial correlation distribution map. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0020] Example 1: like Figure 1 As shown, the method for measuring vector beam concurrency based on single-shot speckle spatial correlation of the present invention includes the following steps: S1: Scatter the vector beam to be measured into a spatially incoherent light field; transform the incoherent light field into a partially coherent light field after Fourier transform; collect the original speckle intensity distribution map of the partially coherent light field in the central region of the Fourier transform plane; S2: Perform background correction on the original speckle intensity distribution map to obtain an optimized speckle intensity distribution map. Then, perform spatial self-correlation operation on the optimized speckle intensity distribution map according to the spatial correlation function to obtain a normalized spatial correlation distribution map. Read the value of the zero displacement point in the normalized spatial correlation distribution map as the correlation value. S3: Calculate the optical concurrency of the vector beam based on the preset linear relationship between the correlation value and the optical concurrency.

[0021] This invention scatters the vector beam under test into a spatially incoherent light field, converts it into a partially coherent light field via Fourier transform, and acquires the original speckle pattern in a single exposure at the center region of the generated Fourier plane. Background correction and spatial autocorrelation operations are performed on the speckle pattern to extract zero-displacement point values. Finally, optical concurrency is calculated based on a preset linear relationship. This method requires only a single exposure to obtain key information, significantly improving measurement efficiency. Furthermore, the method based on spatial autocorrelation to extract zero-displacement point values ​​has high noise resistance and measurement accuracy, effectively avoiding interference from multiple measurements or complex environments.

[0022] Each paraxial vector beam can be represented as: , (1) in, , The spatial distribution function of the complex amplitude; These are the horizontal position coordinates; , Let them be orthogonal basis vectors, satisfying .like and There is a linear relationship ( If the electric field is constant, then the above electric field will degenerate into uniformly polarized light, that is, pure scalar light.

[0023] As shown in equation (1), the two internal degrees of freedom, polarization and spatial mode, cannot be decomposed into the product of independent factors, forming a local classical entangled state based on their non-separable degree of freedom characteristics. This vector characteristic can be quantified by the optical concurrency C: , (2) The range of C is from 0 (representing pure scalar light) to 1 (representing pure vector light), where Represents the spatial average scalar product of the selected spatial pattern.

[0024] For pure amplitude spatial modes, the overlap term can be directly derived from intensity measurements; while for complex spatial modes, the coherence in equation (2) can be expressed using global Stokes parameters: (3) in represent Integral on the spatial surface. The four Stokes parameters can be expressed as: , , (4) , , All four Stokes parameters are real values ​​and have definite physical meanings: This represents the total light intensity, while , and It is closely related to the selected polarization basis vectors. If the basis vectors and Corresponding to horizontal polarization With vertical polarization ,but , and These correspond to the differences between horizontal and vertical linear polarization components, the differences between 45° and −45° linear polarization components, and the differences between right-handed and left-handed circular polarization components, respectively.

[0025] As can be seen from the above, the calculation of optical concurrency in traditional methods is related to global Stokes parameters, which requires a beam splitting system, cannot be measured in real time, and has complex equipment.

[0026] The present invention scatters the vector beam to be tested into a spatially incoherent light field. Specifically, in step S1, the vector beam described by equation (1) is passed through a scattering plate, and it is assumed that: the scattering plate is independent of polarization; the size of the scattering unit is much smaller than the incident beam; and the complex light field of the x and y components after scattering satisfies Gaussian statistics.

[0027] Then, on the second source surface after passing through the scattering plate system, the cross-spectral density matrix element of the partially coherent light is: (5)

[0028] in , (6) The coherence function matrix represents the spatially incoherent beam; These are the spatial coordinates on the second source plane. For wave vector, The focal length of the lens. Let be the Dirac function, indicating that the scattering plate converts the incident coherent light into a spatially incoherent light field.

[0029] Furthermore, the incoherent light field is transformed into a partially coherent light field through a Fourier transform. This incoherent light field is then passed through a lens, and a physical Fourier transform is performed on the scattered light field to obtain the partially coherent light field: , (7) in The polarization matrix associated with the polarization state: , (8) Its matrix elements can be represented as: , , , (9) .

[0030] As can be seen from equation (7), the coherence matrix is ​​actually a Fourier transform of the polarization matrix of an incoherent light source. Therefore, according to equation (5), the relationship between the Stokes parameters at any two points on the second source surface and the incident light Stokes parameters can be obtained: , (10) when Equation (10) can be simplified to , (11) Substituting equation (11) into equation (3) will yield the following result: , (12) in This indicates the degree of polarization of the light field.

[0031] The electromagnetic coherence of a light beam is expressed by the following formula: (13) in , (14) in The trace operation of a matrix is ​​represented by the symbol. This indicates the conjugate transpose.

[0032] Further, in step S2, the original speckle intensity distribution map is subjected to background correction to obtain an optimized speckle intensity distribution map. Then, spatial autocorrelation operation is performed on the optimized speckle intensity distribution map according to the spatial correlation function to obtain a normalized spatial correlation distribution map.

[0033] Combining equations (12) and (13), we can obtain the following relation: , (15) Next, the normalized strength correlation is defined as , (16) in Indicates a point in space The instantaneous power of light, It represents the ensemble average.

[0034] Under the condition that the light field satisfies Gaussian statistics, following (17)

[0035] Equation (17) establishes the relationship between polarization degree and electromagnetic coherence, indicating that polarization degree also measures the degree of coherence of two orthogonal electric field components at the same spatial point in a vector light field.

[0036] Since the degree of polarization ranges from 0 to 1, it can be seen from equation (17) that the autocorrelation function satisfies the following inequality: (18)

[0037] The above equation shows that the vector part of the coherent light field is not necessarily completely autocorrelated (the coherence at the same point is less than 1), because the mutually perpendicular electric field components at that point are not necessarily completely coherent.

[0038] Therefore, by combining equations (15) and (17), we can obtain (19)

[0039] Further, in step S2, the method for background correction of the original speckle intensity distribution map is as follows: symmetrically crop a square sub-image of the central region from the original speckle intensity distribution map, acquire a dark field noise map under the same exposure conditions, and perform pixel-by-pixel subtraction operation between the square sub-image and the dark field noise map to obtain the optimized speckle intensity distribution map.

[0040] By symmetrically cropping a square sub-image of the central region from the original image, the core region in the Fourier transform plane is accurately located, effectively suppressing the polarization matrix Fourier spectrum distortion caused by lens edge diffraction; synchronously acquiring dark field noise images under the same exposure conditions and performing pixel-by-pixel subtraction operations can eliminate the calculation deviation caused by noise pollution, so that the optimized speckle intensity distribution map strictly satisfies the Gaussian statistical assumption, and finally ensure the accuracy of the solution result of equation (19). Especially in turbulent disturbance environments, this correction process maintains the robustness and accuracy of the concurrent degree measurement method by eliminating the multiplied background noise.

[0041] In step S3, when obtaining the optical concurrency, the correlation value of the zero displacement point in the normalized spatial correlation distribution map is selected. As a core input parameter, this operation is determined by both theoretical essence and measurement uniqueness. The fundamental reason is that when the spatial displacement is zero, the statistical characteristics of some coherent light fields undergo a key simplification, making the correlation value at the zero displacement point... It directly carries the physical information of electromagnetic coherence at the same point, and this parameter quantifies the coherence of the orthogonal electric field components in the vector beam, that is, the core feature of the inseparability of polarization and spatial mode; at the same time, the zero displacement point implies the complete integral of the global polarization matrix of the incident light, while other displacement points only reflect the spatial out-of-point coherence, which is unrelated to the global polarization integral required for concurrency, and cannot meet the accuracy requirements in actual measurement due to the exponential attenuation of the signal and the degradation of anti-interference ability.

[0042] Therefore, the correlation value of the zero displacement point The pre-defined linear relationship between the optical concurrency C and the optical concurrency C is expressed by the following formula: (20)

[0043] Example 2: like Figure 2 As shown, based on the same inventive concept as Embodiment 1, the present invention also provides an apparatus for measuring the concurrency of a vector beam based on single-shot speckle spatial correlation, to realize the method for measuring the concurrency of a vector beam based on single-shot speckle spatial correlation described in Embodiment 1, comprising: Rotating frosted glass is used to scatter the incident vector beam of the test object into a spatially incoherent light field; A lens is used to convert the incoherent spatial light field into a partially coherent light field after Fourier transform. An image sensor, whose photosensitive surface is in close contact with the rear glass surface of the lens along the direction of the incident vector beam to be measured, is used to acquire the original speckle intensity distribution map of a partially coherent light field. The calculation module is used to perform background correction on the original speckle intensity distribution map to obtain an optimized speckle intensity distribution map; perform spatial self-correlation operation to generate a normalized spatial correlation distribution map, and read the value of the zero displacement point in the normalized spatial correlation distribution map as the correlation value; and calculate the optical concurrency of the vector beam according to the preset linear relationship between the correlation value and the optical concurrency.

[0044] Specifically, the vector beam to be measured is incident on a slowly rotating frosted glass that satisfies Gaussian statistical characteristics. Along the incident path of the beam, a lens with a focal length of f = 150 mm is placed 15 cm away from the rotating frosted glass, which is one focal length.

[0045] The vector beam to be measured can have any polarization state distribution, such as radial, angular, or hybrid polarization. The rotating frosted glass undergoes special treatment to ensure its optical properties satisfy Gaussian statistics; optionally, it can be frosted glass or a holographic diffuser. The mirror's optical axis is strictly collinear with the propagation direction of the vector beam to be measured. When selecting a lens, priority is given to lenses with a large aperture to collect as much incoherent light as possible from the backscattered frosted glass, reducing light energy loss and improving the signal-to-noise ratio. Simultaneously, the lens collimates and converges the incoherent light scattered by the frosted glass, transforming it into a partially coherent light field with specific coherence characteristics.

[0046] Furthermore, an image sensor with its operating parameters adjusted is placed close to the back of the lens to directly capture the speckle intensity distribution map after it has been converged and collimated by the lens. The image sensor can be a CMOS or CCD, and has high linearity and low readout noise.

[0047] Optionally, the present invention selects CMOS as the image sensor.

[0048] A small hole is pre-drilled at the center of the rotating frosted glass, which is rigidly connected to the shaft of a high-precision DC servo motor or stepper motor via a precision clamp. The motor speed is precisely controlled by a digitally programmable chopper controller. The controller sets the motor's rotation period T. To ensure that the rotation of the frosted glass is sufficient to achieve adequate statistical stationarity (i.e., satisfy the ergodicity assumption) of the scattered light field within the single exposure integration time of the CMOS image sensor, its rotation period T is related to the exposure time of the image sensor. satisfy This is to ensure that the speckle pattern is fully uniform.

[0049] Furthermore, the photosensitive surface of the image sensor is in close contact with the rear glass surface of the lens along the direction of the incident vector beam to be measured, and the center of the photosensitive surface of the image sensor coincides with the optical axis of the lens; the image sensor acquires the original speckle intensity distribution map within a single exposure cycle.

[0050] The operating parameters of CMOS are systematically calibrated and optimized based on traditional scalar light (such as completely unpolarized uniform thermal light or completely polarized laser light) under the same optical path, with the goal of maximizing the signal-to-noise ratio (SNR) and linear dynamic range of speckle images.

[0051] Optionally, the optimization parameters are: Exposure Time: 12000 (12ms). This value must meet the following requirements. The conditions are such that the gray value of the brightest speckle in the speckle pattern acquired by the CMOS is close to the saturation value of the sensor (e.g., close to 255), but at the same time, large-area oversaturation must be avoided to ensure that the dynamic range of the sensor is fully utilized and the sensitivity of speckle contrast measurement is maximized. Fine-tuning can be performed by monitoring the histogram or average gray value in real time. Gamma value: 1.03. The gamma value is set slightly greater than 1 (close to linearity) to slightly compensate for any non-linearity in the sensor or to indicate any potential non-linear response, ensuring accurate recording of intensity values. It should be as linearly proportional as possible to the actual incident light intensity; Black Level: 0%, disables all manually added DC bias. This operation is to ensure that the background dark level corresponds to the sensor's mean noise floor. Other fixed parameters: Gain is set to the lowest available value, typically 0 dB, to minimize readout noise; White Balance is set to Manual or Off; Binning is set to 1x1 to preserve the highest spatial resolution; Trigger Mode is set to Free Run or Software Trigger.

[0052] The device is used under stable lighting and environmental conditions, preferably in a dark room, to trigger CMOS to capture a single frame of speckle intensity distribution, thus acquiring the original speckle intensity distribution of a part of the coherent light field.

[0053] Optionally, the original speckle intensity distribution map is imported into the calculation module, i.e., the original speckle intensity map obtained from the photograph is imported into the calculation module. (Size 2448 × 2048) Import into the MATLAB numerical computation environment. From A 2048 × 2048 pixel square sub-image is symmetrically cropped from the central area. Record the coordinates of the cropped area and acquire a dark-field image with the same exposure time under no-light conditions. Its dimensions are also 2048×2048.

[0054] from Subtract from each pixel The speckle pattern after background correction is obtained. This eliminates the effects of dark current and fixed-mode noise.

[0055] According to the spatial correlation function defined in equation (16) of the embodiment, the corrected speckle map is subjected to spatial autocorrelation operation to obtain a two-dimensional normalized spatial correlation distribution map. (The dimensions are also 2048×2048, centered at (1025, 1025)), the graph is at zero displacement ( There is a sharp peak at point (), and the distribution around it reflects the spatial coherence structure of the speckle field. See example. Figure 1 6. Due to discrete pixelation, the zero-displacement point precisely corresponds to the correlation graph. The center pixel (1025, 1025). The value of this pixel is directly read as... , which is the global maximum value in the correlation distribution.

[0056] Since the frosted glass used in the device satisfies Gaussian statistics, the vector degree of the light field to be measured can be obtained from the spatial correlation value based on the linear relationship described by equation (19) when the light field satisfies Gaussian statistics.

[0057] Example 3: The present invention also provides an electronic device, which includes a processor, a memory, and a bus system. The processor and the memory are connected through the bus system. The memory is used to store instructions, and the processor is used to execute the instructions stored in the memory to implement the method for measuring vector beam concurrency based on single speckle spatial correlation as described in Embodiment 1.

[0058] Example 4: The present invention also provides a computer storage medium storing a computer software product, the computer software product including several instructions for causing a computer device to execute the method for measuring vector beam concurrency based on single speckle spatial correlation as described in Embodiment 1.

[0059] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0060] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0061] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0062] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0063] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for measuring vector beam concurrency based on single-shot speckle spatial correlation, characterized in that, Includes the following steps: S1: Scatter the vector beam to be measured into a spatially incoherent light field; transform the incoherent light field into a partially coherent light field after Fourier transform; collect the original speckle intensity distribution map of the partially coherent light field in the central region of the Fourier transform plane; S2: Perform background correction on the original speckle intensity distribution map to obtain an optimized speckle intensity distribution map. Then, perform spatial self-correlation operation on the optimized speckle intensity distribution map according to the spatial correlation function to obtain a normalized spatial correlation distribution map. Read the value of the zero displacement point in the normalized spatial correlation distribution map as the correlation value. S3: Calculate the optical concurrency of the vector beam based on the preset linear relationship between the correlation value and the optical concurrency.

2. The method for measuring vector beam concurrency based on single-shot speckle spatial correlation according to claim 1, characterized in that: In step S2, the method for background correction of the original speckle intensity distribution map is as follows: symmetrically crop a square sub-image of the central region from the original speckle intensity distribution map, acquire a dark field noise image under the same exposure conditions, and perform pixel-by-pixel subtraction operation between the square sub-image and the dark field noise image to obtain the optimized speckle intensity distribution map.

3. The method for measuring vector beam concurrency based on single-shot speckle spatial correlation according to claim 1, characterized in that: In step S3, the preset linear relationship between the correlation value and the optical concurrency is expressed by the following formula: ， in, For optical concurrency, For associated values, .

4. A device for measuring the concurrency of a vector beam based on single-shot speckle spatial correlation, characterized in that, include: Rotating frosted glass is used to scatter the incident vector beam of the test object into a spatially incoherent light field; A lens is used to convert the incoherent spatial light field into a partially coherent light field after Fourier transform. An image sensor, whose photosensitive surface is in close contact with the rear glass surface of the lens along the direction of the incident vector beam to be measured, is used to acquire the original speckle intensity distribution map of a partially coherent light field. The calculation module is used to perform background correction on the original speckle intensity distribution map to obtain an optimized speckle intensity distribution map; perform spatial self-correlation operation to generate a normalized spatial correlation distribution map, and read the value of the zero displacement point in the normalized spatial correlation distribution map as the correlation value; and calculate the optical concurrency of the vector beam according to the preset linear relationship between the correlation value and the optical concurrency.

5. The device for measuring vector beam concurrency based on single-shot speckle spatial correlation according to claim 4, characterized in that: The lens is positioned at a distance of one focal length from the rotating frosted glass.

6. The device for measuring vector beam concurrency based on single-shot speckle spatial correlation according to claim 4, characterized in that: The rotating frosted glass rotates at a low speed, and its rotation period T is related to the exposure time of the image sensor. satisfy .

7. The device for measuring vector beam concurrency based on single-shot speckle spatial correlation according to claim 4, characterized in that: The photosensitive surface of the image sensor is in close contact with the rear glass surface of the lens along the direction of the incident vector beam to be measured, and the center of the photosensitive surface of the image sensor coincides with the optical axis of the lens; the image sensor acquires the original speckle intensity distribution map within a single exposure cycle.

8. The device for measuring vector beam concurrency based on single-shot speckle spatial correlation according to claim 4, characterized in that: The image sensor is a CMOS sensor or a CCD sensor.

9. An electronic device, characterized in that, The electronic device includes a processor, a memory, and a bus system. The processor and the memory are connected through the bus system. The memory is used to store instructions, and the processor is used to execute the instructions stored in the memory to implement the method for measuring vector beam concurrency based on single speckle spatial correlation as described in any one of claims 1 to 3.

10. A computer storage medium, characterized in that, The computer storage medium stores a computer software product, the computer software product including several instructions for causing a computer device to execute the method for measuring vector beam concurrency based on single speckle spatial correlation as described in any one of claims 1 to 3.

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