Uniform two-dimensional light spot dot matrix generation system and method based on spatial light modulator

Abstract

The invention discloses a uniform two-dimensional light spot dot matrix generation system and method based on a spatial light modulator. The system comprises a laser, a half-wave plate, a thin film polaroid, a first lens, a second lens, a beam splitter, the spatial light modulator, a camera and a terminal, wherein the laser, the half-wave plate, the thin film polaroid, the first lens, the second lens, the beam splitter and the spatial light modulator are sequentially arranged at the same central axis. The half-wave plate and the thin film polaroid form an adjustable light intensity module; the first lens and the second lens form a laser beam expanding module; the beam splitter is used for splitting the expanded laser into two beams through the beam splitter, and one beam enters the spatial light modulator, is reflected and then is reflected to the camera through the beam splitter; the camera transmits a collected light spot image to the terminal in real time, and the terminal generates a new phase diagram by analyzing and calculating the light spot image and feeds back the phase diagram to the spatial light modulator. According to the system and the method, the uniformity of the light spot dot matrix can be continuously optimized, so that the intensity distribution of the generated two-dimensional light spot dot matrix is remarkably improved to a higher uniformity level from an initial lower level.

Description

Technical Field

[0001] This invention relates to a uniform two-dimensional light spot array generation system, specifically to a uniform two-dimensional light spot array generation system and method based on a spatial light modulator. Background Technology

[0002] Two-dimensional light spot arrays with high intensity uniformity have wide applications in laser processing, optical trapping, optical tweezers, and physical experiments. These light fields can achieve multi-point parallel action while maintaining high energy density, offering advantages such as high processing efficiency, uniform energy distribution, and flexible control. Therefore, they are of great significance for improving the uniformity of light spots.

[0003] Currently, spatial light modulators (SLMs) can be used to modulate the phase of incident light, thereby obtaining a two-dimensional lattice of light spots in the far field. However, due to the inevitable aberrations and scattering introduced by optical components such as lenses, polarizers, and mirrors in the optical path, the intensity differences among the light spots in the lattice are large and the distribution is non-uniform. This non-uniformity not only disrupts the ideal distribution of the periodic light field but also seriously affects the stability and repeatability of laser processing and light field manipulation.

[0004] To address the above problems, existing methods mainly fall into the following two categories: (1) Manual optical path optimization method: By continuously adjusting the axial and angular positions of optical components (such as lenses), aberrations are eliminated or reduced, thereby achieving uniformity of the light spot array. However, this method has obvious drawbacks: the adjustment process depends on the operator's experience and has a large subjective error; multiple fine adjustments and tests are required, which is time-consuming and inefficient; even after repeated optimization, residual aberrations are still difficult to completely eliminate, and the uniformity of the light spot is difficult to guarantee.

[0005] (2) Manual optical field compensation method: Before generating the phase map, the initial intensity distribution of the input optical field is manually adjusted to compensate for aberrations or dispersion effects in the optical path transmission. Although this method can improve the difference in light spot intensity to a certain extent, the compensation process requires repeated manual trials, which is inefficient and difficult to automate. Moreover, its optimization effect is heavily dependent on the operator's experience and cannot achieve stable and repeatable uniform output, which directly affects the quality consistency of applications such as laser processing.

[0006] (3) Existing compensation methods are mostly "open-loop" or "one-time" compensation, which cannot cope with the dynamic changes in the optical path caused by time, temperature and other factors.

[0007] In summary, existing spatial light modulation techniques still suffer from problems such as complex operation, low efficiency, and insufficient uniformity when generating highly uniform two-dimensional light spot arrays.

[0008] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0009] The purpose of this invention is to provide a uniform two-dimensional light spot array generation system and method based on a spatial light modulator. This solves the problems of uneven light spot intensity distribution caused by optical path aberrations and scattering during the generation of two-dimensional light spot arrays in existing technologies, as well as the complexity, low efficiency, and difficulty in achieving automated control of manual optimization and compensation methods. The system of this invention can quickly respond to changes in light spot intensity and continuously optimize the uniformity of the light spot array, significantly improving the system's automation level and control efficiency. This results in a more consistent intensity distribution in the generated two-dimensional light spot array. Furthermore, it features real-time, closed-loop, and adaptive characteristics. Experiments show that the system of this invention can automatically improve the uniformity of a 5×5 light spot array from approximately 0.73 before optimization to over 0.95 within 50 iterations through closed-loop feedback, with a root mean square error (RMS) of less than 0.05 for its intensity distribution.

[0010] To achieve the above objectives, this invention provides a uniform two-dimensional light spot array generation system based on a spatial light modulator. The system comprises: a laser, a half-wave plate, a thin-film polarizer, a first lens, a second lens, a beam splitter, and a spatial light modulator arranged sequentially along the same central axis, as well as a camera and a terminal. The half-wave plate and the thin-film polarizer constitute an adjustable light intensity module, used to continuously adjust the ratio of horizontally polarized to vertically polarized light of the laser by rotating the angle of the half-wave plate, thereby controlling the light intensity incident on the spatial light modulator and ensuring that the incident light is a single horizontally polarized light. The first lens and the second lens form a laser beam expanding module, used to enlarge the laser spot diameter to prevent damage to the spatial light modulator due to excessive incident light power. The beam splitter is 50°. A 50-beam splitter is used to split the expanded laser beam into two beams. One beam is incident on the spatial light modulator, reflected by the spatial light modulator, and then reflected by the beam splitter to the camera. The terminal is connected to the spatial light modulator and the camera via a bus. The camera transmits the acquired spot image to the terminal in real time. The terminal analyzes and calculates the spot image to generate a new phase map and feeds the phase map back to the spatial light modulator to achieve closed-loop, active feedback control.

[0011] Preferably, the focal length of the first lens is 50 mm, the focal length of the second lens is 300 mm, and the laser beam expander module increases the diameter of the laser spot by 6 times.

[0012] Preferably, the camera is a complementary metal-oxide-semiconductor (CMOS) camera.

[0013] Preferably, the control system in the terminal includes: an initial parameter setting module, an image analysis module, and a correction module; wherein, the initial parameter setting module is used to set an initial target two-dimensional square light spot array distribution map and convert it into a phase map for transmission to the spatial light modulator; the image analysis module is used to analyze the intensity of the two-dimensional light spot array in the light spot image; the correction module is connected to the image analysis module and is used to receive the intensity analysis results transmitted by the image analysis module, multiply points with excessive intensity in the light spot by a correction coefficient less than 1, multiply points with excessive intensity in the light spot by a correction coefficient greater than 1, thereby calculating a new corrected phase map, and transmitting the corrected phase map to the spatial light modulator.

[0014] More preferably, the correction module integrates a weighted Gerchberg-Saxton feedback algorithm.

[0015] More preferably, the image analysis module integrates a centroid localization algorithm.

[0016] A second objective of this invention is to provide a method for generating a uniform two-dimensional light spot array based on a spatial light modulator, the method comprising the following steps: S1: Load the initial phase map into the spatial light modulator to generate an initial two-dimensional light spot array; S2: Acquire an image of the initial two-dimensional light spot array; S3: Analyze the intensity distribution of each light spot in the image; S4: Based on the difference between the intensity distribution and the target intensity distribution, calculate the corrected phase diagram using an iterative feedback algorithm; S5: Load the corrected phase map into the spatial light modulator, and repeat steps S2 to S5 until the uniformity of the generated light spot array meets the preset conditions.

[0017] Preferably, in step S3, the intensity distribution of each light spot in the image is analyzed using the centroid localization method.

[0018] Preferably, in step S4, the weighted Gerchberg-Saxton feedback algorithm is used to calculate the corrected phase map.

[0019] Preferably, in step S4, the corrected phase diagram is calculated, and points with excessive intensity in the light spot are multiplied by a correction factor less than 1, and points with excessively low intensity in the light spot are multiplied by a correction factor greater than 1.

[0020] The uniform two-dimensional light spot array generation system and method based on spatial light modulator of the present invention solves the problems of uneven light spot intensity distribution caused by optical path aberration and scattering during the generation of two-dimensional light spot arrays in the prior art, as well as the problems of complex operation, low efficiency and difficulty in achieving automatic control of manual optimization and compensation methods. It has the following advantages: (1) The system of the present invention can precisely and continuously adjust the intensity of light incident on the spatial light modulator by setting an adjustable light intensity module, ensuring that the incident light is in a single polarization direction, providing a stable polarization state basis for subsequent light field modulation; the laser beam expander module effectively expands the laser spot diameter, avoiding damage to the spatial light modulator due to excessive power, and improving the safety and stability of the system; the beam splitter works with the spatial light modulator to realize the modulation and reflection path design of the optical signal, while the feedback control unit composed of the camera and the terminal acquires the spot image in real time and performs intensity analysis. The correction module in the terminal control system dynamically generates the corrected phase map according to the analysis results and feeds it back to the spatial light modulator to form a closed-loop control mechanism. This active feedback control method does not require manual intervention, can quickly respond to changes in spot intensity, continuously optimize the uniformity of the spot array, significantly improve the automation level and control efficiency of the system, and make the generated two-dimensional spot array have higher consistency in intensity distribution, better meeting the application requirements of uniform light fields in laser processing, optical capture and other fields;

[0021] (2) The system and method of the present invention utilize a spatial light modulator to dynamically adjust the phase of the light field and achieve real-time feedback through the light spot intensity distribution collected by the camera. Based on the iterative algorithm, the intensity of each light spot in the dot matrix is ​​automatically corrected to compensate for aberrations or optical non-ideal factors in the optical path. After N iterations, a high uniformity two-dimensional light spot array that meets the experimental requirements can be obtained. Finally, the uniformity of the two-dimensional dot matrix light spot can reach RMS<0.05. (3) The system and method of the present invention achieve adaptive correction of light spot intensity at low cost and high efficiency, significantly improving the uniformity of the two-dimensional light spot array generated by spatial light modulation. It has the advantages of strong scientificity, simple operation, low cost and high practicality. Automatic light field optimization can be achieved without manual adjustment of the optical path. The uniformity of the obtained two-dimensional spatial light spot array is significantly improved, greatly improving experimental efficiency. The system structure is simple, and the required devices are all conventional optical components, which are easy to obtain and maintain. It is suitable for various scenarios such as laser processing, laser target ablation, optical tweezers and light field shaping, and has broad engineering application prospects. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the uniform two-dimensional light spot array generation system based on a spatial light modulator according to the present invention.

[0023] Figure 2This is a flowchart of the uniform two-dimensional light spot array generation system based on a spatial light modulator according to the present invention.

[0024] Figure 3 The figures show the two-dimensional light spot array distribution obtained by the system of the present invention after the feedback optimization algorithm (a), the two-dimensional light spot array distribution obtained before the feedback optimization algorithm (b), and the relationship curve of the light spot array uniformity with the number of optimization cycles (c). Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that: Unless otherwise specified in the examples, conditions should be followed according to standard conditions or the manufacturer's recommendations. Instruments whose manufacturers are not specified are all commercially available products. Raw materials and reagents whose manufacturers are not specified are all commercially available goods or can be prepared using known methods.

[0027] In this invention, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are used only for simplicity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0028] The features mentioned in this invention can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification, provided that there is no contradiction in the combination of these features. Each feature disclosed in the specification can be replaced by any alternative feature that provides the same, equivalent, or similar purpose. Therefore, unless otherwise specified, the disclosed features are merely general examples of equivalent or similar features.

[0029] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. The terms "first," "second," "third," etc., and similar relational terms are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] Example 1 A uniform two-dimensional light spot array generation system based on a spatial light modulator includes: a laser 1, a half-wave plate 2, a thin-film polarizer 3, a first lens 4, a second lens 5, a beam splitter 6, and a spatial light modulator 7, arranged sequentially along the same central axis; a camera 8; and a terminal 9. The half-wave plate 2 and the thin-film polarizer 3 constitute an adjustable light intensity module, used to continuously adjust the ratio of horizontally polarized to vertically polarized light of the laser by rotating the angle of the half-wave plate 2, thereby controlling the light intensity incident on the spatial light modulator 7 and ensuring that the incident light is a single horizontally polarized light. The first lens 4 and the second lens 5 form a laser beam expander module, used to enlarge the laser spot diameter to prevent damage to the spatial light modulator 7 due to excessive incident light power. The beam splitter 6 is a 50:50 beam splitter, used to split the expanded laser beam into two beams. One beam is incident on the spatial light modulator 7, reflected by the spatial light modulator 7, and then reflected by the beam splitter 6 to the camera 8.

[0031] Terminal 9 is connected to spatial light modulator 7 and camera 8 via a bus. Camera 8 transmits the acquired light spot image to terminal 9 in real time. Terminal 9 analyzes and calculates the light spot image to generate a new phase map, and feeds the phase map back to spatial light modulator 7 to achieve active feedback control. Spatial light modulator 7 can perform phase modulation on the incident horizontally polarized laser. By loading different phase maps, it can control the wavefront of the light field, thereby generating the required two-dimensional light spot array in the far field.

[0032] For example, the laser has a wavelength of 355nm and an output power of 3mW. Choosing a wavelength of 355nm provides a high degree of matching with the phase modulation curve of the SLM. The spatial light modulator 7 has a resolution of 1920×1080 pixels, a pixel size of 8.0 μm, and a bit depth of 8 bits (256 gray levels). High resolution is the basis for generating a high-precision, low-crosstalk phase map.

[0033] For example, terminal 9 can be a computer, camera 8 can transmit data to computer in real time via USB 3.0 data cable, and spatial light modulator 7 can be connected to computer via HDMI data cable provided by the manufacturer.

[0034] Furthermore, the first lens 4 has a focal length of 50 mm, and the second lens 5 has a focal length of 300 mm. The laser beam expander module increases the laser spot diameter by 6 times. The beam expansion ratio is 6:1. This precise beam expansion ratio ensures that the beam can completely cover the effective aperture of the SLM, while keeping the power density within a safe range.

[0035] Furthermore, camera 8 is a complementary metal-oxide-semiconductor (CMOS) camera. CMOS cameras are characterized by small size, low power consumption, and high integration. They can acquire images of light spots formed after reflection by a spatial light modulator and quickly transmit the image data to the terminal via a bus. This provides reliable image data for the terminal to perform light spot intensity analysis and phase map correction, effectively ensuring the system's efficiency in actively controlling the uniformity of the two-dimensional light spot array.

[0036] For example, camera 8 is a complementary metal-oxide-semiconductor camera with a resolution of 400×1340 and a bit depth of 16 bits. The high bit depth ensures the dynamic range and accuracy of light intensity measurement, which is a prerequisite for accurate feedback.

[0037] Furthermore, the control system in terminal 9 includes an initial parameter setting module, an image analysis module, and a correction module. The initial parameter setting module sets the initial target two-dimensional square light spot array distribution map and converts it into a phase map, which is then transmitted to the spatial light modulator 7. The image analysis module analyzes the intensity of the two-dimensional light spot array in the light spot image. The correction module, connected to the image analysis module, receives the intensity analysis results transmitted by the image analysis module, multiplies points with excessively high intensity in the light spot by a correction coefficient less than 1, and multiplies points with excessively low intensity in the light spot by a correction coefficient greater than 1, thereby calculating a new corrected phase map, which is then transmitted to the spatial light modulator 7.

[0038] For example, the initial parameter setting module, image analysis module, and correction module in terminal 9 are implemented collaboratively by the central processing unit (CPU), system memory (RAM), and human-computer interaction devices (such as keyboard, mouse, and display) of terminal 9.

[0039] The hardware implementation is as follows: The user inputs the distribution parameters of the target two-dimensional light spot array (such as the number of rows and columns m×n and the spacing d) into the system via a human-computer interaction device (the algorithm is based on Matlab software). After receiving these parameters, the CPU allocates storage space in the system memory, calls the initialization algorithm program pre-stored in a solid-state drive (SSD), and performs calculations. Based on the input parameters, the program generates an initial phase map data matrix corresponding to the target spot array distribution, and transmits this data matrix to the subsequent modules and the driver hardware of the spatial light modulator 7 via a high-speed HDMI interface.

[0040] The raw bokeh image data acquired by camera 8 is transmitted in real time to the system memory (RAM) plugged into the terminal motherboard via a USB 3.0 interface, where it is then imaged by the camera's imaging software. Matlab performs image analysis algorithms on the image data: first, binarization and noise filtering are applied to the image; then, a centroid localization algorithm is executed to accurately identify and mark the position of each bokeh in the image; finally, the average grayscale value of the pixels within each bokeh region is calculated as the measured light intensity value I of that bokeh. i The data is then organized into a light intensity distribution data array. This data array is stored in system memory for the next module to read.

[0041] The correction module reads the light intensity distribution data array {I} generated by the image analysis module from system memory. i Matlab calls the correction algorithm program, which controls the arithmetic logic unit to convert the measured intensity I of each light spot. i With the preset target intensity I target Compare them and apply the weighting formula W. i =(Itarget / I i ) k Iterative calculations are performed. During the calculation process, the CPU's floating-point unit is responsible for performing core operations such as exponentiation, multiplication, and division. Based on the calculation results, a correction weight W corresponding to each light spot is generated. i Based on this weighted array, a new, corrected phase map data matrix is ​​calculated under CPU control using a specific phase recovery algorithm (such as the weighted Gerchberg-Saxton algorithm). This new phase map data is sent to the spatial light modulator (7) via the HDMI interface to complete one feedback control cycle.

[0042] For example, in the correction module of terminal 9, the iteration termination condition is: the optimization process automatically terminates when any of the following conditions are met: (1) Convergence condition: The uniformity of the light spot calculated in three consecutive iterations is greater than 0.95; (2) Maximum number of iterations: The number of iterations reaches the preset upper limit of 50.

[0043] Weight W i = (Target Intensity I) target / Measured strength I i ) k (1) Wherein, the exponent k is an adjustable convergence factor, usually taken as 0.1~0.75, used to control the convergence speed and stability of the algorithm. This formula (1) achieves the suppression of excessively strong light spots (W i <1), enhance the weak light spot (W) i >1) Adaptive correction.

[0044] For the method of using the uniform two-dimensional light spot array generation system based on spatial light modulator of the present invention, please refer to [link to documentation]. Figure 2 The details are as follows: During implementation, terminal 9 sets the initial target two-dimensional square light spot array distribution map in MATLAB software. The number of two-dimensional light spots can be set to m*n (m is the number of rows and n is the number of columns), and the spacing between the spots can be set. Terminal 9 uses an iterative correction algorithm to convert the two-dimensional light spot array into a phase map. This phase map is transmitted to spatial light modulator 7 to control its pixel voltage distribution, thereby forming the initial two-dimensional light spot array in the reflected light field.

[0045] At this point, due to the aberrations of optical components such as lenses and mirrors, the initial light spot array exhibits significant intensity non-uniformity. After camera 8 captures the light spot distribution, terminal 9 performs intensity analysis on it, multiplying points with excessively high intensity in the light spot by a correction factor less than 1, and multiplying points with excessively low intensity in the light spot by a correction factor greater than 1, thereby calculating a new corrected phase map.

[0046] The updated phase map is transmitted again to the spatial light modulator 7, where the reflected laser light is captured by the camera 8 to obtain a second optimized spot image, which is then fed back to the terminal 9 for spot uniformity analysis. Through this active feedback process, the system can automatically correct the intensity of each spot in the dot matrix, compensate for optical path aberrations, and achieve adaptive equalization of spot intensity.

[0047] This iterative optimization process can be repeated N times until the uniformity of the light spot array reaches the preset standard.

[0048] See the experimental results. Figure 3 , Figure 3 (a) shows the 2D 5x5 light spot distribution obtained after the feedback optimization algorithm, (b) shows the 2D 5x5 light spot distribution before the feedback optimization algorithm, and (c) shows the relationship between the uniformity of the light spot array and the number of optimization cycles. A standard for uniformity is preset during the iteration process. The dashed line guides the threshold line for uniformity. It can be seen that before iteration, the uniformity of the laser dot matrix is ​​only 0.73. After approximately 50 iterations (each iteration takes 3-4 seconds, varying depending on the hardware processing speed), it is optimized to a uniformity >0.95. Specific optimization results can be seen from... Figure 3 In (a) (after optimization) and (b) (before optimization), a laser array with uniform brightness and good spot quality is clearly obtained.

[0049] Through the aforementioned closed-loop feedback control, the system of this invention achieves automated optimization of the uniformity of a two-dimensional light spot array. Experiments show (see...) Figure 3 For a 5x5 light spot array, its uniformity can be steadily improved from approximately 0.73 before optimization to over 0.95 after about 50 iterations (total time approximately 3-4 minutes). This process requires no manual intervention, solving the problems of traditional methods relying on experience, low efficiency, and non-reproducible results. It is especially suitable for industrial scenarios with high requirements for processing consistency.

[0050] After multiple iterations, the uniformity of the two-dimensional light spot array obtained by the system of the present invention is significantly improved, and the uniformity RMS value can be lower than 0.05, which meets the requirements of high-precision experiments.

[0051] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A uniform two-dimensional light spot array generation system based on a spatial light modulator, characterized by, The system comprises a laser (1), a half-wave plate (2), a thin film polarizer (3), a first lens (4), a second lens (5), a beam splitter (6) and a spatial light modulator (7) arranged in sequence at the same central axis, and a camera (8) and a terminal (9); The half-wave plate (2) and the thin film polarizer (3) constitute an adjustable light intensity module, which is used to continuously adjust the ratio of horizontal polarized light and vertical polarized light of the laser by rotating the angle of the half-wave plate (2), so as to control the light intensity incident on the spatial light modulator (7) and ensure that the incident light is single horizontal polarized light. The first lens (4) and the second lens (5) constitute a laser beam expander module for expanding the laser spot diameter. The beam splitter (6) is a 50:50 beam splitter, which is used to divide the expanded laser into two beams, one of which is incident on the spatial light modulator (7), reflected by the spatial light modulator (7), and then reflected by the beam splitter (6) to the camera (8). The terminal (9) is connected to the spatial light modulator (7) and the camera (8) through a bus, the camera (8) transmits the collected spot image to the terminal (9) in real time, and the terminal (9) generates a new phase map by analyzing and calculating the spot image, and feeds back the phase map to the spatial light modulator (7) to realize closed loop and active feedback control.

2. The spatial light modulator based uniform two-dimensional light spot array generating system of claim 1, wherein, The focal length of the first lens (4) is 50 mm, and the focal length of the second lens (5) is 300 mm. The laser beam expander module expands the laser spot diameter by 6 times.

3. The spatial light modulator based uniform two-dimensional light spot array generating system according to claim 1 or 2, characterized in that, The control system in the terminal (9) comprises an initial parameter setting module, an image analysis module and a correction module. The initial parameter setting module is used to set an initial target two-dimensional square spot lattice distribution map and convert it into a phase map transmitted to the spatial light modulator (7). The image analysis module is used to analyze the intensity of the two-dimensional spot lattice in the spot image. The correction module is connected with the image analysis module and is used to receive the intensity analysis result transmitted by the image analysis module, multiply the points with too high intensity in the spot by a correction coefficient less than 1, multiply the points with too low intensity in the spot by a correction coefficient greater than 1, thereby calculating a new corrected phase map, and transmitting the corrected phase map to the spatial light modulator (7).

4. The spatial light modulator based uniform two-dimensional light spot array generating system of claim 3, wherein, The correction module is integrated with a weighted Gerchberg-Saxton feedback algorithm.

5. The spatial light modulator based uniform two-dimensional light spot array generating system of claim 3, wherein, The image analysis module is integrated with a centroid positioning algorithm.

6. A method for generating a uniform two-dimensional array of light spots based on a spatial light modulator, characterized in that The method comprises the following steps: S1: load an initial phase map to the spatial light modulator to generate an initial two-dimensional spot lattice; S2: collect an image of the initial two-dimensional spot lattice; S3: analyze the intensity distribution of each spot in the image; S4: calculate a corrected phase map based on an iterative feedback algorithm according to the difference between the intensity distribution and a target intensity distribution; S5: load the corrected phase map to the spatial light modulator, and repeat steps S2-S5 until the uniformity of the generated spot lattice meets a preset condition.

7. The spatial light modulator based uniform two-dimensional light spot array generation method of claim 6, wherein, In step S3, the analysis of the intensity distribution of each spot in the image uses a centroid positioning method.

8. The spatial light modulator based uniform two-dimensional light spot array generation method of claim 6, wherein, In step S4, the calculation of the corrected phase map uses a weighted Gerchberg-Saxton feedback algorithm.

9. The spatial light modulator based uniform two-dimensional light spot array generating method according to any one of claims 6-8, wherein, In step S4, the calculation of the corrected phase map multiplies points with too high intensity in the spot by a correction factor less than 1 and points with too low intensity in the spot by a correction factor greater than 1.

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