An optical beam wavefront measurement device, a control method of an optical beam wavefront measurement device

Abstract

The application provides a kind of light beam wavefront measurement device, the control method of light beam wavefront measurement device, laser system and electronic equipment.The application can accurately adjust the height and attitude of sensing module by introducing first adjusting module and second adjusting module, so as to realize high-precision wavefront measurement of large-size light beam.A plurality of hartmann dot array images collected at different heights are processed by splicing, to generate a larger size complete hartmann dot array image, thereby breaking through the problem of insufficient wavefront measurement resolution caused by the sensing size limitation of a single hartmann wavefront sensor.In addition, the accurate control of the control module and the optimization of the splicing algorithm make the spliced dot array image more smoothly connected in the overlapping area, ensuring the accuracy and continuity of the measurement results, thereby improving the wavefront measurement accuracy and reliability of large-size light beam.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of light beam wavefront measurement, and in particular to a light beam wavefront measurement device, a control method of the light beam wavefront measurement device, a laser system and an electronic device. BACKGROUND

[0002] Wavefront measurement is a technique for evaluating the shape of a light wavefront, and the main purpose is to detect the distortion or distortion of the light beam during propagation. Hartmann wavefront sensor divides the light beam into a plurality of small sub-beams, and uses the displacement or phase change of each sub-beam to infer the shape of the entire light wavefront.

[0003] The existing measurement scheme cannot meet the high-precision wavefront measurement requirement of large-size rectangular light beams. SUMMARY

[0004] The present application aims to overcome the above technical deficiencies, and provides a light beam wavefront measurement device, a control method of the light beam wavefront measurement device, a laser system and an electronic device, to solve the technical problem that the existing measurement scheme cannot meet the high-precision wavefront measurement requirement of large-size rectangular light beams in the related art.

[0005] To achieve the above technical purpose, the present application adopts the following technical scheme:

[0006] In a first aspect, the present application provides a light beam wavefront measurement device, comprising:

[0007] a sensing module for collecting a first Hartmann dot array of an incident light beam with a target size; wherein the target size is greater than the sensing size of the sensing module;

[0008] a first adjusting module for adjusting the height of the sensing module;

[0009] a second adjusting module for adjusting the attitude of the sensing module;

[0010] a control module electrically connected to the sensing module, and configured to receive at least two first Hartmann dot arrays collected by the sensing module at different heights, wherein the two first Hartmann dot arrays collected at adjacent heights have an overlapping area with a preset size; and perform splicing processing on the at least two first Hartmann dot arrays to obtain a complete second Hartmann dot array; wherein the size of the second Hartmann dot array is greater than the size of the first Hartmann dot array.

[0011] Further, the width of the overlapping area satisfies a first preset condition and a second preset condition; the first preset condition is that the width of the overlapping area is an integer multiple of the pixel size of the sensing module and the sub-aperture spacing; and the second preset condition is that the width of the overlapping area is an integer multiple of the adjustment precision of the first adjustment module.

[0012] Further, the control module is further electrically connected with the second adjustment module, and the control module is further configured to, before performing the measurement, dynamically generate a control signal based on an optimization target of minimizing a target difference and send the control signal to the second adjustment module, so that the second adjustment module automatically adjusts the current attitude of the sensing module, so that the photosensitive surface of the sensing module is parallel to the wavefront profile of the incident light beam; the target difference is the sum of the centroid offsets of each sub-aperture image in the first Hartmann dot array and a preset calibration zero point; and the calibration zero point is a calibration zero point coordinate calibrated by a standard parallel light pipe.

[0013] Further, the control module is further configured to perform stitching processing on the at least two first Hartmann dot arrays based on a preset stitching algorithm to obtain a complete second Hartmann dot array.

[0014] Further, the first adjustment module is an electric fine adjustment platform, which is electrically connected with the control module and is configured to, during the measurement, automatically adjust the height of the sensing module with a preset precision based on the control signal sent by the control module, so that the first Hartmann dot arrays collected by the sensing module at different heights have a required overlapping area, thereby ensuring the measurement precision of the second Hartmann dot array after stitching.

[0015] Further, the second adjustment module is an electric rotating platform, the sensing module is detachably connected with the electric rotating platform, the electric rotating platform cooperates with the vertical displacement adjustment function of the first adjustment module, and the electric rotating platform is used to adjust the rotation angle and the pitch angle of the sensing module, so that the photosensitive surface of the sensing module is parallel to the wavefront profile of the incident light beam, thereby realizing accurate wavefront measurement.

[0016] In a second aspect, the application provides a control method of a light beam wavefront measurement device, the light beam wavefront measurement device comprising a sensing module, a first adjustment module, a second adjustment module and a control module, wherein the sensing module is used to collect a first Hartmann dot array of an incident light beam with a target size, the target size being greater than the sensing size of the sensing module; the first adjustment module is used to adjust the height of the sensing module; the second adjustment module is used to adjust the attitude of the sensing module; and the method comprises:

[0017] The sensor module receives at least two first Hartmann dot matrix images acquired at different heights; wherein the two first Hartmann dot matrix images acquired at adjacent heights have an overlapping area of ​​a preset size.

[0018] A stitching process is performed on the at least two first Hartmann dot patterns to obtain a complete second Hartmann dot pattern; wherein the size of the second Hartmann dot pattern is larger than the size of the first Hartmann dot pattern.

[0019] Thirdly, the present invention provides a laser system including the aforementioned beam wavefront measurement device.

[0020] Fourthly, the present invention provides an electronic device, comprising: a memory, and one or more processors communicatively connected to the memory; the memory stores instructions executable by the one or more processors, the instructions being executed by the one or more processors to cause the one or more processors to implement the method described above.

[0021] Beneficial effects:

[0022] This invention, by introducing a first adjustment module and a second adjustment module, enables precise adjustment of the height and orientation of the sensing module, thereby achieving high-precision wavefront measurement of large-size beams. Multiple Hartmann dot patterns acquired at different heights are stitched together to generate a larger, complete Hartmann dot pattern, overcoming the problem of insufficient wavefront measurement resolution caused by the size limitation of a single Hartmann wavefront sensor. Furthermore, the precise control of the control module and the optimization of the stitching algorithm result in smoother connections in overlapping areas of the stitched dot pattern, ensuring the accuracy and continuity of the measurement results, thus improving the accuracy and reliability of wavefront measurement for large-size beams. Attached Figure Description

[0023] Figure 1 This is a block diagram of a beam wavefront measurement device used in an embodiment of the present invention;

[0024] Figure 2 This is a flowchart illustrating a control method for a beam wavefront measurement device provided in an embodiment of the present invention;

[0025] Figure 3 This is a block diagram of a large-size rectangular beam wavefront measurement device provided in an embodiment of the present invention;

[0026] Figure 4 This is a block diagram of a large-size rectangular beam wavefront measurement device provided in an embodiment of the present invention;

[0027] Figure 5 This is a scene example diagram of a large-size rectangular beam wavefront measurement method provided in an embodiment of the present invention;

[0028] Figure 6 This is a scenario example diagram of a large-size rectangular beam wavefront measurement method provided in an embodiment of the present invention. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0030] In related technologies, particularly in modern optical manufacturing, high-energy laser systems, and precision optical inspection, wavefront quality is a core indicator for evaluating beam performance, especially in high-precision applications. For example, in semiconductor lithography, high-precision wavefront control is required to ensure image accuracy and resolution during the lithography process. Similarly, in the surface shape inspection of large-aperture telescopes, precise wavefront measurement is needed to verify whether the mirror shape meets design requirements, ensuring high-resolution imaging in astronomical observations. These applications commonly involve wavefront measurement of large rectangular beams with high precision requirements. In these contexts, high-precision wavefront measurement technology is crucial for ensuring beam quality and improving system performance.

[0031] In related technologies, Hartmann wavefront sensors are often used as standard wavefront measurement tools. Their working principle is as follows: the incident wavefront passes through a microlens array, which decomposes the wavefront into multiple small light spots, forming a dot matrix on the focal plane of the detection camera. By calculating the centroid offset of each light spot, the wavefront of the beam is reconstructed.

[0032] However, existing Hartmann wavefront sensors face a significant physical limitation: the target surface size of commercially available detector cameras is typically small, which makes it impossible for them to directly cover the cross-section of large beams, especially for large rectangular beams, where the sensors cannot effectively capture the wavefront information of the entire beam.

[0033] In related technologies, to address the difficulty of measuring large beams using Hartmann wavefront sensors, existing solutions typically involve adding a beam-shrinking system in front of the sensor. This involves using optical beam-shrinking techniques to compress the spatial size of the large beam, making the beam match the sensor's detection aperture, thereby enabling wavefront measurement of large rectangular beams.

[0034] In a specific embodiment of a related technology, a wavefront detection device is disclosed. Specifically, multiple beam splitters are placed in front of a Hartmann wavefront sensor to split the input beam into multiple sub-beams. A wavefront sensor is installed in the direction of each sub-beam, and the combination of multiple sensors is used to acquire wavefront information of a large-area beam. Each wavefront sensor includes a microlens array and an area array camera, and the target surface of the area array camera coincides with the focal plane of the microlens array to improve the accuracy of slope measurement. The slope matrix is ​​then formed by measuring the slope at corresponding points of each wavefront sensor. Then, the wavefront equation is derived using the measurement results of the wavefront sensors, and wavefront reconstruction is performed using a high-resolution wavefront reconstruction algorithm. This method can combine data from multiple wavefront sensors to obtain a comprehensive, high-precision wavefront information. It is understood that although this embodiment improves resolution by using multiple wavefront sensors, it still involves beam splitting and sub-beam generation. The use of beam splitters will cause beam intensity attenuation and may introduce additional aberrations, especially in the measurement of large rectangular beams, where the synthesis of multiple beams may lead to inconsistencies in wavefront measurements. While this implementation overcomes the spatial resolution limitation, the split beam may still face issues such as aberration contamination. Secondly, this implementation relies on data processing from multiple wavefront sensors and complex algorithm derivations. Although its design improves resolution, the amount of data processing increases with the number of sensors, especially in high-frequency measurements.

[0035] Therefore, it is understandable that while existing beam-shrinking schemes can adapt to the aperture of Hartmann wavefront sensors to some extent, they cannot meet the requirements for high-precision wavefront measurement of large rectangular beams due to the aberration contamination they cause.

[0036] In summary, existing measurement methods cannot meet the high-precision wavefront measurement requirements of large-size rectangular beams.

[0037] like Figure 1 As shown, this embodiment provides a beam wavefront measurement device, which may include:

[0038] A sensing module for acquiring a first Hartmann dot pattern of an incident light beam having a target size; wherein the target size is larger than the sensing size of the sensing module.

[0039] In this embodiment, the sensing module can be a Hartmann wavefront sensor. Specifically, the Hartmann wavefront sensor includes a microlens array and a probe camera. The target surface of the probe camera coincides with the focal plane of the microlens array. The sub-lenses of the microlens array are square in shape, and the size of the reconstructed grid sub-aperture is consistent with that of the sub-lenses of the microlens array.

[0040] In this embodiment, the sensing module can also be a computational Hartmann sensor. That is, a dot matrix is ​​generated equivalently using a spatial light modulator (SLM) and a computational reconstruction algorithm. In one possible and specific implementation, the computational Hartmann sensor may include a spatial light modulator, a single-pixel detector, and a built-in control unit, wherein the built-in control unit has a pre-set computational reconstruction algorithm. Specifically, the spatial light modulator is used to modulate the wavefront of the incident light beam. The single-pixel detector is used to receive the light beam modulated by the spatial light modulator. The single-pixel detector obtains wavefront information by detecting the intensity of the modulated light. The computational reconstruction algorithm is responsible for processing the data collected by the spatial light modulator and the single-pixel detector and reconstructing the dot matrix.

[0041] In this embodiment, the beam with the target size can be a large-size rectangular beam. Specifically, the large size can be a size that meets the requirements of industrial laser processing. For example, the large size can be a long side of not less than 200mm and a short side of not less than 50mm.

[0042] In this embodiment, the sensing size of the sensing module is represented by the detection aperture of the detection camera of the Hartmann wavefront sensor.

[0043] The first adjustment module is used to adjust the height of the sensing module.

[0044] In this embodiment, the first adjustment module can be an electric fine-tuning platform. Specifically, the electric fine-tuning platform is electrically connected to the control module and is configured to automatically adjust the height of the sensing module with a preset accuracy based on the control signal sent by the control module during the measurement process, so that the first Hartmann dot matrix images collected by the sensing module at different heights have the required overlapping area, thereby ensuring the measurement accuracy of the stitched second Hartmann dot matrix image.

[0045] In this embodiment, the first adjustment module can be a pneumatic adjustment platform. That is, the height of the adjustment platform is controlled by air pressure, thereby adjusting the height of the sensing module.

[0046] In this embodiment, the first adjustment module can be a stepper motor adjustment device. The stepper motor can drive the platform to perform precise vertical displacement adjustment, enabling control with high precision and small step size.

[0047] In this embodiment, the first adjustment module can be a hydraulic adjustment platform. The hydraulic adjustment platform controls the vertical movement of the platform through a hydraulic pump.

[0048] In this embodiment, the first adjustment module can also be a precision screw lifting device. That is, the height of the sensing module is adjusted using a screw lifting mechanism.

[0049] In this embodiment, the first adjustment module may also be a servo motor adjustment device.

[0050] The second adjustment module is used to adjust the attitude of the sensing module.

[0051] In this embodiment, the second adjustment module can be an electric rotating platform. The sensing module is detachably connected to the electric rotating platform. The electric rotating platform works in conjunction with the vertical displacement adjustment function of the first adjustment module. The electric rotating platform is used to adjust the rotation angle and pitch angle of the sensing module so that the photosensitive surface of the sensing module is parallel to the wavefront profile of the incident beam, thereby achieving accurate wavefront measurement.

[0052] In this embodiment, the second adjustment module can be a manual differential rotary table. The manual differential rotary table may include a rotating base, a dual-axis adjustment mechanism, a differential adjustment head, and a dial. Specifically, the dual-axis adjustment mechanism may include two rotating axes, used to adjust the pitch angle (vertical adjustment) and rotation angle (horizontal rotation), respectively. Each axis is equipped with an independent knob, allowing the adjustment of the two angles to be independent of each other, ensuring fine adjustment. Each rotating axis knob is equipped with a differential head, providing very fine angle adjustment. By rotating the knob, the differential head can achieve high-precision angle adjustment, ensuring accurate attitude control of the sensing module on both axes. The dial is used to indicate the angle change for each rotation, helping the user to accurately position and adjust to the desired angle.

[0053] In this embodiment, the second adjustment module may be a piezoelectric ceramic deflection platform.

[0054] In this embodiment, the second adjustment module can be a ball joint + differential screw mechanism.

[0055] A control module, which is electrically connected to at least the sensing module, is configured to receive at least two first Hartmann dot matrix images acquired by the sensing module at different heights, acquire two first Hartmann dot matrix images at adjacent heights with an overlapping area of ​​a preset size, and then perform a stitching process on the at least two first Hartmann dot matrix images to obtain a complete second Hartmann dot matrix image; wherein the size of the second Hartmann dot matrix image is larger than the size of the first Hartmann dot matrix image.

[0056] In this embodiment, the control module can also be electrically connected to the first adjustment module and the second adjustment module.

[0057] In this embodiment, the control module may be a microcontroller.

[0058] In this embodiment, the control module may be a digital signal processor.

[0059] In this embodiment, the control module may be a field-programmable gate array (FPGA).

[0060] In this embodiment, the control module can be an industrial PC plus an image acquisition card.

[0061] In this embodiment, the control device can perform splicing processing on the at least two first Hartmann dot matrix images based on a preset splicing algorithm to obtain a complete second Hartmann dot matrix image.

[0062] Specifically, the preset splicing algorithm can be a centroid offset minimization algorithm.

[0063] The preset stitching algorithm can be a sub-aperture image peak intensity matching algorithm. That is, registration is performed using the peak intensity coordinates of each sub-aperture spot.

[0064] The preset stitching algorithm can be an image cross-correlation peak matching algorithm. That is, the overlapping areas are treated as two-dimensional image blocks for cross-correlation calculation.

[0065] The preset stitching algorithm can be a deep learning-based spot registration model. This model can learn the spatial mapping relationship between adjacent Hartmann dot patterns through end-to-end training.

[0066] In one specific and possible implementation, the deep learning-based spot registration model may include:

[0067] The Siamese convolutional neural network, acting as a feature extractor, processes two first Hartmann dot maps (adjacent Hartmann dot map pairs) simultaneously through a shared weight structure. The Siamese convolutional neural network can effectively extract similarity and difference features between the two images and can identify the relative positional relationships of various light spots in a wavefront image.

[0068] The feature fusion layer generates spatial transformation parameters. The output features of the Siamese convolutional neural network are merged through the feature fusion layer to generate spatial transformation parameters for image registration. This layer is responsible for fusing the feature information of the two first Hartmann dot maps to form a global description used to calculate the geometric transformation between the images.

[0069] Spatial transformation networks are used to perform differentiable distortions on images. They enable affine transformations (rotation, translation, scaling) and precise subpixel-level alignment. This network allows images to be deformed precisely according to predicted spatial transformation parameters, ensuring accurate alignment of light spot positions.

[0070] The beneficial effect of this embodiment is that by introducing the first adjustment module and the second adjustment module, the height and attitude of the sensing module can be precisely adjusted, thereby achieving high-precision wavefront measurement of large-size beams. Multiple Hartmann dot patterns acquired at different heights are stitched together to generate a larger, complete Hartmann dot pattern, thus overcoming the problem of insufficient wavefront measurement resolution caused by the size limitation of a single Hartmann wavefront sensor. Furthermore, the precise control of the control module and the optimization of the stitching algorithm result in smoother connections in overlapping areas of the stitched dot patterns, ensuring the accuracy and continuity of the measurement results, thereby improving the accuracy and reliability of wavefront measurement for large-size beams.

[0071] In some embodiments, the width of the overlapping region satisfies a first preset condition and a second preset condition; wherein, the first preset condition means that the width of the overlapping region is an integer multiple of the sensor module pixel size and the sub-aperture spacing; and the second preset condition means that the width of the overlapping region is an integer multiple of the adjustment precision of the first adjustment module.

[0072] This embodiment achieves several beneficial effects by setting the width of the overlapping region to simultaneously satisfy two constraints: the width must be an integer multiple of the sensor module pixel size and the sub-aperture spacing, and also an integer multiple of the adjustment precision of the first adjustment module. First, optical alignment accuracy is significantly improved. The requirement of an integer multiple of the pixel size ensures that the image is aligned pixel-by-pixel during stitching, effectively eliminating the distortion of the wavefront gradient caused by sub-pixel registration errors and significantly reducing accuracy loss. Second, the compatibility of mechanical control is enhanced. By setting the width of the overlapping region to an integer multiple of the adjustment precision of the first adjustment module, it ensures that the displacement device can naturally achieve physical alignment when adjusting with minimal steps, avoiding errors caused by accumulated positioning deviations. Finally, the stability of the algorithm is also guaranteed. Ensuring that the width of the overlapping region is an integer multiple of the sub-aperture spacing allows the overlapping region to completely contain the sub-aperture grid cells, maintaining the topological consistency of the wavefront reconstructed grid before and after stitching.

[0073] In some embodiments, the control module is also electrically connected to the second adjustment module, and the control module is further configured to dynamically generate a control signal and send it to the second adjustment module before performing the measurement, based on an optimization target that minimizes the target difference, so that the second adjustment module automatically adjusts the current attitude of the sensing module, thereby making the photosensitive surface of the sensing module parallel to the wavefront profile of the incident beam; wherein, the target difference is the sum of the centroid offsets of each sub-aperture image in the first Hartmann dot matrix and a preset calibration zero point; wherein, the calibration zero point is represented by the coordinates of the calibration zero point calibrated by a standard collimator.

[0074] In this embodiment, the control module cooperates with the second adjustment module via an electrical connection to control the working state of the second adjustment module. The second adjustment module is used to adjust the attitude of the sensing module, that is, the rotation angle and the pitch angle, so that the photosensitive surface of the sensing module remains parallel to the wavefront profile of the light beam.

[0075] Before performing the measurement, the control module dynamically generates a control signal based on the optimization objective of minimizing the target difference and sends it to the second adjustment module, so that the photosensitive surface of the sensing module is precisely aligned with the wavefront profile of the incident beam during the measurement.

[0076] In this embodiment, a calibration step is required before actual wavefront measurement to ensure the accuracy of the Hartmann wavefront sensor and the reliability of wavefront measurement. The calibration process uses a standard collimator to ensure the parallelism and distortion-free nature of the beam, thus providing the wavefront sensor with a standard, flat wavefront. It is understood that a standard collimator is an optical device capable of emitting a parallel beam without optical distortion. This device provides the Hartmann wavefront sensor with an ideal, flat wavefront, enabling the sensing module to accurately capture the wavefront information of the beam during measurement.

[0077] During calibration, the sensing module needs to be kept parallel to the standard collimator. That is, the photosensitive surface of the sensing module must be parallel to the wavefront profile of the incident beam, because only under these conditions can the sensing module accurately capture the spot at the standard position. Under the illumination of the parallel beam emitted by the standard collimator, the sensing module can measure a set of ideal spot positions, which are the calibration zero points. The calibration zero points represent the ideal spot positions that the sensing module should measure when the beam wavefront is completely flat. The calibration process ensures that the sensing module can accurately capture the wavefront information of the beam during actual measurements by confirming these calibration zero points.

[0078] It is understandable that the calibration process requires ensuring the sensor module is parallel to the standard collimator. If they are not parallel, the acquired Hartmann dot plot will no longer be standard and will not accurately reflect the wavefront shape of the beam. Therefore, the calibration process needs to ensure the parallelism between the sensor module and the standard collimator to guarantee that the acquired dot plot reflects distortion-free wavefront information.

[0079] This embodiment achieves several beneficial effects by electrically connecting the control module and the second adjustment module, dynamically generating control signals and automatically adjusting the attitude of the sensing module based on the optimization objective of minimizing target differences. First, automatically adjusting the sensor module's attitude ensures that its photosensitive surface is always parallel to the wavefront profile of the incident beam, greatly improving the accuracy of wavefront measurement. Second, by using the calibration zero point as a reference, the control module can accurately calculate and optimize the centroid offset of each sub-aperture image, eliminating systematic errors caused by incorrect attitude. Finally, this method reduces manual intervention by optimizing target differences, improving the stability and efficiency of the measurement process, while enhancing the system's automation level, making it suitable for high-precision wavefront measurement environments.

[0080] In some embodiments, the control module is further configured to perform stitching processing on the at least two first Hartmann dot matrix images based on a preset stitching algorithm to obtain a complete second Hartmann dot matrix image.

[0081] Specifically, the preset splicing algorithm can be a centroid offset minimization algorithm.

[0082] The preset stitching algorithm can be a sub-aperture image peak intensity matching algorithm. That is, registration is performed using the peak intensity coordinates of each sub-aperture spot.

[0083] The preset stitching algorithm can be an image cross-correlation peak matching algorithm. That is, the overlapping areas are treated as two-dimensional image blocks for cross-correlation calculation.

[0084] The preset stitching algorithm can be a deep learning-based spot registration model. This model can learn the spatial mapping relationship between adjacent Hartmann dot patterns through end-to-end training.

[0085] In one specific and possible implementation, the deep learning-based spot registration model may include:

[0086] The Siamese convolutional neural network, acting as a feature extractor, processes two first Hartmann dot maps (adjacent Hartmann dot map pairs) simultaneously through a shared weight structure. The Siamese convolutional neural network can effectively extract similarity and difference features between the two images and can identify the relative positional relationships of various light spots in a wavefront image.

[0087] The feature fusion layer generates spatial transformation parameters. The output features of the Siamese convolutional neural network are merged through the feature fusion layer to generate spatial transformation parameters for image registration. This layer is responsible for fusing the feature information of the two first Hartmann dot maps to form a global description used to calculate the geometric transformation between the images.

[0088] Spatial transformation networks are used to perform differentiable distortions on images. They enable affine transformations (rotation, translation, scaling) and precise subpixel-level alignment. This network allows images to be deformed precisely according to predicted spatial transformation parameters, ensuring accurate alignment of light spot positions.

[0089] This embodiment achieves high-precision dot matrix image stitching through various preset stitching algorithms, including a centroid offset minimization algorithm, a sub-aperture image peak intensity matching algorithm, an image cross-correlation peak matching algorithm, and a deep learning-based spot registration model. First, by precisely controlling the position of the spots within the overlapping region, the centroid offset minimization algorithm effectively eliminates stitching errors, ensuring image alignment in the overlapping area. Second, the sub-aperture image peak intensity matching algorithm uses the peak intensity of the spots for precise registration, further improving alignment accuracy during stitching. The image cross-correlation peak matching algorithm treats the overlapping region as a two-dimensional image block for cross-correlation calculations, ensuring image consistency during stitching. Finally, the deep learning-based spot registration model automatically learns the spatial mapping relationship between adjacent Hartmann dot matrices through end-to-end training, enabling the model to provide strong robustness in complex measurement environments, especially under high noise and distortion conditions, further enhancing the accuracy and stability of the stitching algorithm.

[0090] In some embodiments, the first adjustment module is an electric fine-tuning platform, which is electrically connected to the control module and configured to automatically adjust the height of the sensing module with a preset accuracy based on the control signal sent by the control module during the measurement process, so that the first Hartmann dot pattern collected by the sensing module at different heights has the required overlapping area, thereby ensuring the measurement accuracy of the stitched second Hartmann dot pattern.

[0091] In this embodiment, the electric fine-tuning platform may include:

[0092] The platform base, which can be made of metal (aluminum alloy or stainless steel), supports the second adjustment module. (That is, the sensor module is mounted on the second adjustment module, which is located on the platform base. This allows the height of the sensor module to be adjusted via an electrically adjustable platform, while the second adjustment module adjusts the sensor module's attitude.) Specifically, the second adjustment module (e.g., an electrically operated rotary platform) can be fixed or mounted on the platform base. The platform base can be connected to the second adjustment module via mounting holes or connection interfaces. Screws or threaded interfaces can be used to securely mount the second adjustment module to the platform base. Furthermore, during installation, the horizontal and vertical positions of the second adjustment module must be precisely aligned so that the sensor module can accurately rotate and pitch in space during attitude adjustments.

[0093] The screw drive system can control the lifting and lowering of the platform base using a screw and micro-stepping motion, specifically through a servo motor.

[0094] To ensure the platform base moves smoothly in the vertical direction, a guide rail and slider system can be provided. Linear guide rails can be used to ensure that the linear movement of the platform base does not deviate from the track and to reduce errors caused by friction.

[0095] The position sensor can be an optical encoder or a magnetic encoder. The position sensor can detect the platform's current position in real time and feed the data back to the control module. Based on the feedback information from the position sensor, the control module can precisely adjust the movement of the servo motors, thereby ensuring that the platform base is adjusted within a preset accuracy.

[0096] This embodiment significantly improves the accuracy and automation of wavefront measurement by employing an electrically adjustable platform as the first adjustment module, which is electrically connected to the control module. During measurement, the electrically adjustable platform automatically adjusts the height of the sensing module based on control signals sent by the control module, ensuring that the Hartmann dot plots acquired at different heights have the required overlap area. This automated adjustment not only reduces human error but also ensures the measurement accuracy of the stitched second Hartmann dot plot, thereby guaranteeing high precision and reliability in wavefront measurement, making it particularly suitable for optical systems requiring high-resolution measurements. Furthermore, by adjusting to a preset precision, the system can stably maintain accurate alignment, improving the efficiency and consistency of the measurement process and adapting to complex experimental environments and demanding measurement tasks.

[0097] In some embodiments, the second adjustment module is an electric rotating platform, and the sensing module is detachably connected to the electric rotating platform. The electric rotating platform cooperates with the vertical displacement adjustment function of the first adjustment module. The electric rotating platform is used to adjust the rotation angle and pitch angle of the sensing module so that the photosensitive surface of the sensing module is parallel to the wavefront profile of the incident beam, thereby achieving accurate wavefront measurement.

[0098] In this embodiment, the electric rotary platform may include:

[0099] A dual-axis rotary mechanism is used to provide independent rotational degrees of freedom in orthogonal directions, meaning that each axis can be controlled independently, allowing for precise attitude calibration and meeting the fine adjustment requirements of the sensing module.

[0100] The drive motor assembly provides power to the dual-axis rotation mechanism of the second adjustment module, enabling highly precise rotation adjustment. Based on instructions from the control module, the drive motor assembly precisely adjusts the movement of the dual-axis rotation mechanism to ensure that the rotation angle of the sensing module reaches the preset requirements.

[0101] An angle feedback system may include an optical encoder. The optical encoder converts the actual rotation angle into a digital signal and feeds it back to the control module by real-time monitoring of the position of the rotating shaft.

[0102] In this embodiment, the electric rotating platform can be fixed or installed on the platform base of the first adjustment module, thereby enabling the electric rotating platform to cooperate with the vertical displacement adjustment function of the first adjustment module.

[0103] This embodiment achieves highly flexible and accurate wavefront measurement by employing a detachable connection between an electric rotary platform and the sensing module. The electric rotary platform, in conjunction with the vertical displacement adjustment function of the first adjustment module, can precisely control the rotation and pitch angles of the sensing module, ensuring that the photosensitive surface of the sensing module is always parallel to the wavefront profile of the incident beam. This design significantly improves the accuracy and stability of wavefront measurement. Automated attitude adjustment not only reduces errors caused by manual intervention but also improves the efficiency and repeatability of the measurement process. Furthermore, the detachable connection of the electric rotary platform gives the system greater flexibility, facilitating module replacement and maintenance, thereby further enhancing the system's reliability and adaptability.

[0104] like Figure 2 As shown, this embodiment provides a control method for a beam wavefront measurement device. The beam wavefront measurement device includes a sensing module, a first adjustment module, a second adjustment module, and a control module. The sensing module is used to acquire a first Hartmann lattice pattern of an incident beam having a target size, where the target size is larger than the sensing size of the sensing module. The first adjustment module is used to adjust the height of the sensing module. The second adjustment module is used to adjust the attitude of the sensing module. The method includes:

[0105] Step S12: Receive at least two first Hartmann dot matrix images acquired by the sensing module at different heights; wherein, the two first Hartmann dot matrix images acquired at adjacent heights have an overlapping area of ​​a preset size.

[0106] Step S14: Perform a stitching process on the at least two first Hartmann dot matrix images to obtain a complete second Hartmann dot matrix image; wherein the size of the second Hartmann dot matrix image is larger than the size of the first Hartmann dot matrix image.

[0107] The control method provided in this embodiment enables high-precision measurement of large-size beam wavefronts by precisely controlling the height and attitude adjustment of the sensing module. First, the control method receives at least two Hartmann dot maps acquired at different heights, ensuring a pre-defined overlap between these dot maps, thus guaranteeing the spatial continuity of the stitched image. Next, these dot maps are stitched together to generate a larger, complete Hartmann dot map, thereby achieving precise measurement of the large-size beam wavefront. This method overcomes the accuracy degradation problem caused by the sensor module's sensing size limitations in traditional measurements, improves the quality of the stitched image, and ensures the accuracy and reliability of wavefront measurement.

[0108] In this embodiment, the step of performing stitching processing on the at least two first Hartmann bitmaps to obtain a complete second Hartmann bitmap includes:

[0109] Step S142: For the initial first Hartmann dot map in the received first Hartmann dot map, adjust the sub-aperture images in the overlapping area to minimize the sum of the centroid offsets of each sub-aperture image and the preset calibration zero point.

[0110] Step S144: For all first Hartmann dot maps other than the initial first Hartmann dot map, adjust the sub-aperture images in their overlapping regions so that the centroid offset of the sub-aperture images in the corresponding overlapping regions of the current first Hartmann dot map and the previous first Hartmann dot map is minimized.

[0111] In this embodiment, it is understood that when two Hartmann bitmaps are captured by adjusting their height, there will be an overlapping area between the two Hartmann bitmaps, which includes the common parts of the adjacent bitmaps. This overlapping area is crucial for ensuring stitching accuracy; it contains the spot or sub-aperture images that need to be aligned.

[0112] In this embodiment, the objective is to adjust the overlapping area between the current first Hartmann dot pattern and the previous first Hartmann dot pattern, minimizing the centroid offset of the sub-aperture images in the corresponding overlapping areas of the two dot patterns. The corresponding overlapping area can be, for example, if the current Hartmann dot pattern is the second Hartmann dot pattern, the corresponding area could be the upper overlapping area of ​​the second Hartmann dot pattern. The goal is to minimize the displacement between the centroid position of the sub-aperture image in the upper overlapping area of ​​the second Hartmann dot pattern and the centroid position of the sub-aperture image in the lower overlapping area of ​​the first Hartmann dot pattern (initial sheet).

[0113] In this embodiment, centroid offset refers to the displacement between the centroid positions of two sub-aperture images. In the overlapping region, each sub-aperture image has a centroid position, and the offset represents the distance between the centroid of the current image and the centroid at the same position in the previous image. To achieve precise stitching, this offset needs to be minimized. By precisely controlling the position of the current bitmap, the centroid offset of the sub-aperture images in the overlapping region of the current bitmap and the previous bitmap is minimized. The current bitmap can be translated or rotated to ensure alignment with the sub-aperture images in the previous bitmap. After adjustment, the overlapping regions of the current bitmap and the previous bitmap will seamlessly connect, ensuring that the stitched image retains complete wavefront information and that the spot positions are precisely aligned.

[0114] This implementation optimizes the alignment accuracy of the light spot positions during the stitching process by precisely adjusting the centroid offset of each sub-aperture image. First, by adjusting the overlapping area in the initial first Hartmann dot matrix image, the centroid offset between each sub-aperture image and the preset calibration zero point is minimized, thus ensuring the precise starting position of the stitched image. Next, for other first Hartmann dot matrix images, the sub-aperture images in their overlapping areas are adjusted to minimize the deviation between adjacent dot matrix images, ensuring precise alignment of the light spot positions within the overlapping area. This method, through meticulous image alignment processing, significantly improves the accuracy of the complete second Hartmann dot matrix image after stitching, guaranteeing high precision and reliability in wavefront measurements. Especially in high-precision optical measurement applications, it provides more stable and accurate stitching results.

[0115] According to an embodiment of the present invention, a laser system is provided, including the above-described beam wavefront measurement device.

[0116] In this embodiment, the laser system can be a laser system used in high-energy laser manufacturing scenarios.

[0117] In this embodiment, the laser system can be a laser system used in semiconductor lithography.

[0118] In this embodiment, the laser system can be a laser system used in medical laser therapy equipment.

[0119] In this embodiment, the laser system may include, in addition to the beam wavefront measurement device described above, a beam transmission module, a wavefront adjustment module, optical elements, and other auxiliary devices, etc.

[0120] In one possible and specific implementation, a large-size rectangular beam wavefront measurement device and its measurement method are provided. This implementation adjusts the height of the Hartmann wavefront sensor using a high-precision displacement adjustment device, and repeatedly acquires Hartmann dot maps of the corresponding region of the rectangular beam. Adjacent acquired dot maps have overlapping areas. These overlapping areas are used to stitch all the dot maps together to form a complete Hartmann dot map corresponding to the rectangular beam. This dot map is used for wavefront reconstruction, achieving high-precision wavefront measurement of large-size rectangular beams.

[0121] Please see Figure 3 This embodiment provides a large-size rectangular beam wavefront measurement device, which includes: a Hartmann wavefront sensor, a high-precision displacement adjustment device, and a two-dimensional adjustment platform;

[0122] The Hartmann wavefront sensor is used to acquire Hartmann dot matrix patterns;

[0123] The high-precision displacement adjustment device is used to adjust the height of the Hartmann wavefront sensor.

[0124] The two-dimensional adjustment platform is used to adjust the rotation and pitch angles of the Hartmann wavefront sensor.

[0125] It should be noted that the photosensitive surface of the Hartmann wavefront sensor should be parallel to the vertical movement direction of the high-precision displacement adjustment device to ensure that the adjustment direction is strictly limited to the vertical direction.

[0126] It should be further explained that the two-dimensional adjustment platform also needs to be adjusted so that the photosensitive surface of the Hartmann wavefront sensor is parallel to the wavefront profile of the rectangular beam. The determination method is to minimize the sum of the centroid offsets of the sub-aperture images of the Hartmann dot matrix in the middle region relative to the calibration zero point (xij0, yij0), i.e., ∑i,j((xij-xij0)+(yij-yij0))=min, i=1,2,…,I,j=1,2,…,J, where I and J are the row and column numbers of the sub-aperture images of the Hartmann dot matrix, respectively; xij, yij represent the centroid coordinates of the sub-aperture spot in the i-th row and j-th column of the Hartmann dot matrix.

[0127] It should be further explained that the calibration zero point (xij0, yij0) is the coordinate of the centroid of the sub-aperture where the tilt aberration of the Hartmann wavefront sensor is minimized on a standard collimator.

[0128] Specifically, the Hartmann wavefront sensor includes a microlens array and a detection camera, but is not limited to the sensor form described above; any sensor capable of reconstructing the wavefront is acceptable.

[0129] Please see Figure 4 , Figure 5 andFigure 6 This embodiment provides a method for measuring the wavefront of a large rectangular beam. The high-precision displacement adjustment device is adjusted to change the height of the Hartmann wavefront sensor, obtaining multiple Hartmann dot plots (1,2,…,n) corresponding to the region of the rectangular beam, as shown below. Figure 4 As shown;

[0130] It should be noted that adjacent acquired dot patterns have a fixed-width overlap area. These overlap areas are used to stitch all the dot patterns together to form a complete Hartmann dot pattern corresponding to a rectangular beam. This dot pattern is used for wavefront reconstruction, such as... Figure 5 As shown;

[0131] The width h of the overlapping region must be an integer multiple of the pixel size s of the Hartmann wavefront sensor and the sub-aperture spacing a, i.e., h%s=0 and h%a=0, to ensure that the dot matrix image moves according to the number of whole pixels and whole apertures. Furthermore, h is an integer multiple of the adjustment accuracy δ of the high-precision displacement adjustment device, i.e., h%δ=0, to ensure that the intensity distribution of each sub-aperture image in the overlapping region on the pixels of the detection camera is basically consistent during the adjustment of the height of the high-precision displacement adjustment device.

[0132] like Figure 6 The algorithm for minimizing the centroid offset in image stitching includes the following steps:

[0133] 1. Reconstruct and fix the mesh, and adjust the Hartmann lattice. Figure 1 The sum of the centroid offsets (Δx1ij, Δy1ij) relative to the calibration zero point (xij0, yij0) is minimized, i.e., ∑i,j(Δx1ij+Δy1ij)=min, i=1,2,…,M, j=1,2,…,N, where M and N are the number of rows and columns of the sub-aperture image of the Hartman dot matrix in the overlapping region, respectively.

[0134] 2. Adjust the Hartmann dot matrix Figure 2 ,make Figure 2 Overlapping region sub-aperture image relative to Figure 1 The centroid offset of the sub-aperture image in the overlapping region is minimized, i.e., ∑i,j(Δx2ij+Δy2ij-Δx1ij-Δy1ij)=min, i=1,2,…,M, j=1,2,…,N;

[0135] 3. Repeat step 2 until the Hartmann dot matrix N is completed.

[0136] Understandably, during the calibration process, the two-dimensional adjustment platform adjusts the rotation and pitch angles of the Hartmann wavefront sensor to ensure that the sensor's photosensitive surface is as parallel as possible to the beam wavefront profile. This allows the Hartmann dot matrix sub-aperture image in the central region to correspond to the calibration zero point, minimizing centroid offset. Specifically:

[0137] This step is to eliminate installation errors and ensure that the Hartmann wavefront sensor is correctly aligned with the wavefront of the beam, thus ensuring accurate measurement data. This step is sensor alignment, which can be achieved by adjusting the position and angle of the sensor to ensure the accuracy of the measurement results.

[0138] By precisely adjusting the wavefront sensor using a two-dimensional adjustment platform, the centroid of the light spot is aligned as closely as possible with the calibration zero point. This minimizes errors caused by inaccurate installation, thereby ensuring the accuracy of the measurement data.

[0139] In this process, the algorithm that minimizes the centroid offset ensures that the calibrated Hartmann lattice image of the sub-aperture reaches the ideal position.

[0140] Image stitching involves combining multiple acquired raster images into a complete rectangular wavefront image. The key to this step lies in handling overlapping areas between images to ensure the accuracy of the stitched result. By stitching multiple raster images and minimizing the centroid offset of the overlapping areas, a seamlessly connected wavefront image is obtained.

[0141] By adjusting the position of each dot pattern (rather than adjusting the sensor itself), the centroid offset of the overlapping sub-aperture images between adjacent images is minimized. During image stitching, the offset minimization algorithm aims to ensure the alignment accuracy between each light spot, guaranteeing that there are no significant errors in the light spots of the stitched image.

[0142] In other words, what is being adjusted here is the position of the image itself, not the angle or position of the sensor.

[0143] The calibration process primarily focuses on the sensor's installation accuracy to ensure that the acquired dot matrix image accurately reflects the wavefront information of the light beam. Image stitching focuses on the accuracy of image synthesis to ensure that wavefront images from multiple regions can be seamlessly stitched together to obtain a complete wavefront image.

[0144] It should be further noted that the minimum offset algorithm is used to stitch the images in this embodiment. Other image matching algorithms, such as sub-aperture image peak intensity matching, image cross-correlation peak matching algorithm, and artificial intelligence, can also be used. That is to say, it includes, but is not limited to, the algorithm mentioned above or other similar algorithms.

[0145] Specifically, the method for reconstructing the wavefront using the stitched Hartmann lattice pattern can be set according to actual needs. This invention does not impose specific limitations on it, as long as the large-size rectangular beam wavefront measurement method proposed in this invention is applicable.

[0146] According to an embodiment of the present invention, an electronic device is provided. The electronic device in this embodiment may include one or more of the following components: a processor, a network interface, memory, non-volatile memory, and one or more application programs, wherein the one or more application programs may be stored in the non-volatile memory and configured to be executed by one or more processors, and the one or more programs are configured to perform the methods described in the foregoing method embodiments.

[0147] According to embodiments of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a computer, causes the computer to perform the method described in any of the above embodiments.

[0148] According to embodiments of the present invention, a computer program product comprising instructions is also provided, which, when executed by a computer, cause the computer to perform a method in any of the above embodiments.

[0149] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0150] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments, and will not be repeated here.

[0151] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0152] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0153] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A light beam wavefront measuring device, characterized by, The application relates to a Hartmann wavefront sensor, comprising: a sensing module for collecting a first Hartmann point array of an incident light beam with a target size; wherein the target size is larger than the sensing size of the sensing module; a first adjusting module for adjusting the height of the sensing module; a second adjusting module for adjusting the attitude of the sensing module; a control module electrically connected with the sensing module, configured to receive at least two first Hartmann point arrays collected by the sensing module at different heights, the two first Hartmann point arrays collected at adjacent heights have a preset size of an overlapping area; perform splicing processing on the at least two first Hartmann point arrays to obtain a complete second Hartmann point array; wherein the size of the second Hartmann point array is larger than the size of the first Hartmann point array; the width of the overlapping area meets a first preset condition and a second preset condition; wherein the first preset condition is that the width of the overlapping area is an integer multiple of the size of a sensing element of the sensing module and the pitch of a sub-aperture; the second preset condition is that the width of the overlapping area is an integer multiple of the adjusting precision of the first adjusting module; the control module is also electrically connected with the second adjusting module, and the control module is further configured to, before measurement, dynamically generate a control signal based on an optimization target of minimizing a target difference and send the control signal to the second adjusting module, so that the second adjusting module automatically adjusts the current attitude of the sensing module, and the photosensitive surface of the sensing module is parallel to the wavefront profile of the incident light beam; wherein the target difference is the sum of the centroid offset of each sub-aperture image in the first Hartmann point array and a preset calibration zero point; wherein the calibration zero point is a calibration zero point coordinate calibrated by a standard collimator; the control module is further configured to perform splicing processing on the at least two first Hartmann point arrays based on a preset splicing algorithm to obtain a complete second Hartmann point array.

2. The apparatus of claim 1, wherein the first adjusting module is an electric fine adjustment platform, which is electrically connected with the control module and is configured to automatically adjust the height of the sensing module with preset precision based on the control signal sent by the control module during measurement, so that the first Hartmann point arrays collected by the sensing module at different heights have the required overlapping area, thereby ensuring the measurement precision of the spliced second Hartmann point array.

3. The apparatus of claim 1, wherein, the second adjusting module is an electric rotating platform, the sensing module is detachably connected with the electric rotating platform, the electric rotating platform is matched with the vertical displacement adjusting function of the first adjusting module, and the electric rotating platform is used for adjusting the rotation angle and the pitch angle of the sensing module, so that the photosensitive surface of the sensing module is parallel to the wavefront profile of the incident light beam, and accurate wavefront measurement is realized.

4. A control method of a light beam wavefront measuring apparatus, characterized by, The light beam wavefront measurement device comprises a sensing module, a first adjusting module, a second adjusting module and a control module, wherein the sensing module is configured to collect a first Hartmann dot array of an incident light beam having a target size, the target size being greater than a sensing size of the sensing module; the first adjusting module is configured to adjust a height of the sensing module; the second adjusting module is configured to adjust a posture of the sensing module; and the method comprises: receiving at least two first Hartmann dot arrays collected by the sensing module at different heights; wherein two first Hartmann dot arrays collected at adjacent heights have an overlapping area with a preset size; performing stitching processing on the at least two first Hartmann dot arrays to obtain a complete second Hartmann dot array; wherein a size of the second Hartmann dot array is greater than a size of the first Hartmann dot array.

5. The method of claim 4, wherein the method further comprises: The step of performing stitching processing on the at least two first Hartmann dot arrays to obtain a complete second Hartmann dot array comprises: for an initial first Hartmann dot array in the received first Hartmann dot arrays, adjusting each sub-aperture image in the overlapping area of the initial first Hartmann dot array such that a sum of centroid offset amounts of each sub-aperture image from a preset calibration zero point is minimum; for a first Hartmann dot array other than the initial first Hartmann dot array, adjusting each sub-aperture image in the overlapping area of the first Hartmann dot array such that a centroid offset amount of a sub-aperture image in a corresponding overlapping area of the current first Hartmann dot array from a sub-aperture image in a corresponding overlapping area of a previous first Hartmann dot array is minimum.

6. A laser system, characterized by, The light beam wavefront measurement device comprises a sensing module, a first adjusting module, a second adjusting module and a control module, wherein the sensing module is configured to collect a first Hartmann dot array of an incident light beam having a target size, the target size being greater than a sensing size of the sensing module; the first adjusting module is configured to adjust a height of the sensing module; the second adjusting module is configured to adjust a posture of the sensing module; and the method comprises:

7. An electronic device, comprising: receiving at least two first Hartmann dot arrays collected by the sensing module at different heights; wherein two first Hartmann dot arrays collected at adjacent heights have an overlapping area with a preset size; performing stitching processing on the at least two first Hartmann dot arrays to obtain a complete second Hartmann dot array; wherein a size of the second Hartmann dot array is greater than a size of the first Hartmann dot array. The step of performing stitching processing on the at least two first Hartmann dot arrays to obtain a complete second Hartmann dot array comprises: for an initial first Hartmann dot array in the received first Hartmann dot arrays, adjusting each sub-aperture image in the overlapping area of the initial first Hartmann dot array such that a sum of centroid offset amounts of each sub-aperture image from a preset calibration zero point is minimum; for a first Hartmann dot array other than the initial first Hartmann dot array, adjusting each sub-aperture image in the overlapping area of the first Hartmann dot array such that a centroid offset amount of a sub-aperture image in a corresponding overlapping area of the current first Hartmann dot array from a sub-aperture image in a corresponding overlapping area of a previous first Hartmann dot array is minimum. The light beam wavefront measurement device comprises a sensing module, a first adjusting module, a second adjusting module and a control module, wherein the sensing module is configured to collect a first Hartmann dot array of an incident light beam having a target size, the target size being greater than a sensing size of the sensing module; the first adjusting module is configured to adjust a height of the sensing module; the second adjusting module is configured to adjust a posture of the sensing module; and the method comprises: receiving at least two first Hartmann dot arrays collected by the sensing module at different heights; wherein two first Hartmann dot arrays collected at adjacent heights have an overlapping area with a preset size; performing stitching processing on the at least two first Hartmann dot arrays to obtain a complete second Hartmann dot array; wherein a size of the second Hartmann dot array is greater than a size of the first Hartmann dot array.

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