Light beam wavefront measuring device, control method of light beam wavefront measuring device, laser system and electronic equipment

Abstract

The invention provides a light beam wavefront measuring device, a control method of the light beam wavefront measuring device, a laser system and electronic equipment. By introducing the first adjusting module and the second adjusting module, the height and the posture of the sensing module can be accurately adjusted, so that high-precision wavefront measurement of a large-size light beam is realized. A plurality of Hartmann lattice diagrams collected at different heights are spliced to generate a complete Hartmann lattice diagram with a larger size, so that the problem of insufficient wavefront measurement resolution caused by sensing size limitation of a single Hartmann wavefront sensor is solved. Besides, through the accurate control of the control module and the optimization of the splicing algorithm, the connection of the spliced lattice diagrams in the overlapping area is smoother, the accuracy and continuity of the measurement result are ensured, and the wavefront measurement precision and reliability of the large-size light beam are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of light beam wavefront measurement, and in particular to a light beam wavefront measurement device, a control method for the light beam wavefront measurement device, a laser system, and electronic equipment. Background Art

[0002] Wavefront measurement is a technique used to evaluate the shape of an optical wavefront. Its primary purpose is to detect distortion or aberrations in a light beam during propagation. Hartmann wavefront sensors split a light beam into multiple sub-beams and use the displacement or phase change of each sub-beam to infer the shape of the entire wavefront.

[0003] Existing measurement solutions cannot meet the needs of high-precision wavefront measurement of large-sized rectangular beams. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned technical deficiencies and provide a light beam wavefront measurement device, a control method for the light beam wavefront measurement device, a laser system and an electronic device to solve the technical problem in the related art that the existing measurement schemes cannot meet the high-precision wavefront measurement requirements of large-size rectangular beams.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a light beam wavefront measurement device, comprising: A sensing module configured to collect a first Hartmann dot pattern of an incident light beam having a target size, wherein the target size is larger than a sensing size of the sensing module; a first adjusting module, configured to adjust the height of the sensing module; a second adjustment module, configured to adjust the posture of the sensing module; A control module is electrically connected to at least the sensing module and is configured to receive at least two first Hartmann dot patterns acquired by the sensing module at different heights, acquire two first Hartmann dot patterns at adjacent heights, and obtain an overlapping area of ​​a preset size; then perform a splicing process 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 that of the first Hartmann dot pattern.

[0006] Furthermore, the width of the overlapping area satisfies a first preset condition and a second preset condition; wherein, the first preset condition is expressed as the width of the overlapping area is an integer multiple of the pixel size and sub-aperture spacing of the sensing module; the second preset condition is expressed as the width of the overlapping area is an integer multiple of the adjustment accuracy of the first adjustment module.

[0007] Furthermore, the control module is also electrically connected to the second adjustment module, and the control module is also configured to dynamically generate a control signal and send it to the second adjustment module based on the optimization goal of minimizing the target difference before performing the measurement, so that the second adjustment module automatically adjusts the current posture of the sensor module, thereby making the photosensitive surface of the sensor module parallel to the wavefront profile of the incident light beam; wherein, the target difference is the sum of the center of mass offset of each sub-aperture image in the first Hartmann dot pattern and the preset calibration zero point; wherein, the calibration zero point is represented by the calibration zero point coordinate calibrated by a standard parallel light tube. Furthermore, the control module is further configured to perform a splicing process on the at least two first Hartmann dot maps based on a preset splicing algorithm to obtain a complete second Hartmann dot map.

[0008] Furthermore, the first adjustment module is an electric fine-tuning platform, which is electrically connected to the control module and is configured to automatically adjust the height of the sensor 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 sensor module at different heights has the required overlapping area, thereby ensuring the measurement accuracy of the second Hartmann dot pattern after splicing.

[0009] Furthermore, 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 light beam, thereby achieving accurate wavefront measurement.

[0010] In a second aspect, the present invention provides a control method for 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 configured to collect a first Hartmann dot pattern of an incident light beam having a target size, the target size being larger than a sensing size of the sensing module; the first adjustment module is configured to adjust the height of the sensing module; and the second adjustment module is configured to adjust the posture of the sensing module. The method comprises: receiving at least two first Hartmann dot patterns acquired by the sensing module at different heights; wherein the two first Hartmann dot patterns acquired at adjacent heights have an overlapping area of ​​a preset size; A stitching process is performed on the at least two first Hartmann dot maps to obtain a complete second Hartmann dot map; wherein the size of the second Hartmann dot map is larger than the size of the first Hartmann dot map.

[0011] In a third aspect, the present invention provides a laser system comprising the above-mentioned beam wavefront measurement device.

[0012] In a fourth aspect, 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, and the instructions are executed by the one or more processors to enable the one or more processors to implement the above-mentioned method.

[0013] Beneficial effects: By introducing a first adjustment module and a second adjustment module, the present invention can precisely adjust the height and posture of the sensing module, thereby achieving high-precision wavefront measurement of large-scale light beams. Multiple Hartmann dot patterns collected at different heights can be spliced ​​together to generate a larger, complete Hartmann dot pattern, thus overcoming the problem of insufficient wavefront measurement resolution caused by the sensing size limitations of a single Hartmann wavefront sensor. Furthermore, the precise control of the control module and the optimization of the splicing algorithm ensure smoother connections in overlapping areas of the spliced ​​dot patterns, ensuring the accuracy and continuity of the measurement results, thereby improving the accuracy and reliability of wavefront measurements of large-scale light beams. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a block diagram of a light beam wavefront measurement device used in an embodiment of the present invention; Figure 2 1 is a flow chart of a control method of a light beam wavefront measurement device provided by an embodiment of the present invention; Figure 3 This is a block diagram of a large-size rectangular beam wavefront measurement device provided by an embodiment of the present invention; Figure 4 This is a block diagram of a large-size rectangular beam wavefront measurement device provided by an embodiment of the present invention; Figure 5 This is a scene example diagram of a large-size rectangular beam wavefront measurement method provided by an embodiment of the present invention; Figure 6 This is a scene example diagram of a large-size rectangular beam wavefront measurement method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0015] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0016] In related technologies, in the fields of modern optical manufacturing, high-energy laser systems, and precision optical testing, wavefront quality is a core indicator for evaluating beam performance, especially in high-precision application scenarios. For example, in the application scenario of semiconductor lithography machines, high-precision wavefront control is required to ensure image accuracy and resolution during the lithography process. For another example, in the application scenario of mirror surface shape detection of large-aperture telescopes, precise wavefront measurement is required to verify whether the mirror surface shape meets the design requirements and ensure high-resolution imaging of the telescope in astronomical observations. In these scenarios, there is a common demand for wavefront measurement of large-size rectangular beams, and the requirements for wavefront accuracy are high. In these applications, high-precision wavefront measurement technology is crucial to ensuring beam quality and improving system performance.

[0017] In related technologies, the Hartmann wavefront sensor is often used as a standard wavefront measurement tool. Its working principle is as follows: the incident wavefront passes through the 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 center of mass offset of each light spot, the wavefront of the light beam is reconstructed.

[0018] However, existing Hartmann wavefront sensors face a significant physical limitation: the target size of commercial detection cameras is usually small, which makes it impossible to directly cover the cross-section of large-size light beams. In particular, for large rectangular beams, the sensor cannot effectively capture the wavefront information of the entire beam.

[0019] To address the difficulty of measuring large beams with Hartmann wavefront sensors, existing solutions typically involve adding a beam reduction system in front of the sensor. This involves using optical beam reduction technology to compress the large beam's spatial dimensions, allowing it to fit within the sensor's detection aperture, thus enabling wavefront measurement of large rectangular beams.

[0020] In a specific embodiment of the related art, a wavefront detection device is disclosed. Specifically, multiple beamsplitters are placed in front of a Hartmann wavefront sensor to split an input light 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 collect wavefront information for a large area of ​​the light beam. Each wavefront sensor includes a microlens array and an area array camera, with the target surface of the area array camera coinciding with the focal plane of the microlens array to improve the accuracy of slope measurement. The slopes of corresponding points on each wavefront sensor are then measured to form a slope matrix. The wavefront equation is then derived using the measurement results from the wavefront sensors, and wavefront restoration is performed using a high-resolution wavefront restoration algorithm. This method combines data from multiple wavefront sensors to obtain comprehensive, high-precision wavefront information. It is understood that while this embodiment uses multiple wavefront sensors to improve resolution, it still involves beam splitting and sub-beam generation. The use of beamsplitters can cause light intensity attenuation in the beam and may introduce additional aberrations. Especially when measuring large rectangular beams, the synthesis of multiple beams can lead to inconsistencies in wavefront measurement. While this implementation addresses spatial resolution limitations, the split beams may still face issues such as aberration contamination. Furthermore, this implementation relies on data processing from multiple wavefront sensors and complex algorithmic derivation. While this design improves resolution, the increased number of sensors also increases the amount of data processing required, particularly when measuring at high frequencies.

[0021] Therefore, it is understandable that although the existing beam reduction scheme can adapt to the aperture of the Hartmann wavefront sensor to a certain extent, it cannot meet the demand for high-precision wavefront measurement of large-size rectangular beams due to the aberration pollution it causes.

[0022] In summary, existing measurement solutions cannot meet the needs of high-precision wavefront measurement of large-sized rectangular beams. like Figure 1 As shown, this embodiment provides a light beam wavefront measurement device, which may include: A sensing module is used to collect a first Hartmann dot pattern of an incident light beam having a target size; wherein the target size is larger than a sensing size of the sensing module.

[0023] In this embodiment, the sensing module may be a Hartmann wavefront sensor. Specifically, the Hartmann wavefront sensor includes a microlens array and a detection camera, wherein the detection camera target plane coincides with the focal plane of the microlens array, the microlens array sub-lenses are square in shape, and the reconstructed grid sub-aperture size is consistent with the microlens array sub-lenses.

[0024] In this embodiment, the sensing module may also be a computational Hartmann sensor. That is, a dot pattern is equivalently generated by a spatial light modulator (SLM) and a computational reconstruction algorithm. In a possible and specific implementation scheme, the computational Hartmann sensor may include a spatial light modulator, a single-pixel detector, and a built-in control unit, and the built-in control unit is preset with a 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 modulated light intensity. 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 pattern.

[0025] In this embodiment, the target-sized beam may be a large rectangular beam. Specifically, the large size may be a size that meets the requirements of industrial laser processing. For example, the large size may be a long side of not less than 200 mm and a short side of not less than 50 mm.

[0026] 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.

[0027] The first adjusting module is used to adjust the height of the sensing module.

[0028] In this embodiment, the first adjustment module may 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 sensor module with a preset accuracy during measurement based on a control signal sent by the control module, so that the first Hartmann dot patterns collected by the sensor module at different heights have a desired overlapping area, thereby ensuring the measurement accuracy of the spliced ​​second Hartmann dot pattern.

[0029] In this embodiment, the first adjustment module may be a pneumatic adjustment platform, that is, the height of the adjustment platform is controlled by air pressure, thereby adjusting the height of the sensor module.

[0030] In this embodiment, the first adjustment module may be a stepper motor adjustment device. The stepper motor can drive the platform to perform precise vertical displacement adjustment and can be controlled with high precision and small step distance.

[0031] In this embodiment, the first adjustment module may be a hydraulic adjustment platform that controls the vertical movement of the platform through a hydraulic pump.

[0032] In this embodiment, the first adjustment module may also be a precision spiral lifting device, that is, a spiral lifting mechanism is used to adjust the height of the sensor module.

[0033] In this embodiment, the first adjustment module may also be a servo motor adjustment device.

[0034] The second adjustment module is used to adjust the posture of the sensing module.

[0035] In this embodiment, the second adjustment module can be 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 light beam, thereby achieving accurate wavefront measurement.

[0036] In this embodiment, the second adjustment module can be a manual differential rotation stage. The manual differential rotation stage 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, which are respectively used to adjust the pitch angle (up and down adjustment) and the rotation angle (horizontal rotation). Each axis is equipped with an independent knob so that the adjustment of the two angles can be independent of each other, ensuring fine adjustment. The knob of each rotating axis is equipped with a differential head, which can provide very detailed angle adjustment. By rotating the knob, the differential head can achieve high-precision angle adjustment, ensuring precise posture control of the sensing module on the two axes. The dial is used to indicate the angle change of each rotation, helping the user to accurately position and adjust to the desired angle.

[0037] In this embodiment, the second adjustment module may be a piezoelectric ceramic deflection platform.

[0038] In this embodiment, the second adjustment module may be a ball hinge + differential screw mechanism.

[0039] A control module is electrically connected to at least the sensing module and is configured to receive at least two first Hartmann dot patterns acquired by the sensing module at different heights, acquire two first Hartmann dot patterns at adjacent heights, and obtain an overlapping area of ​​a preset size; then perform a splicing process 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 that of the first Hartmann dot pattern.

[0040] In this embodiment, the control module may also be electrically connected to the first regulating module and the second regulating module.

[0041] In this embodiment, the control module may be a microcontroller.

[0042] In this embodiment, the control module may be a digital signal processor.

[0043] In this embodiment, the control module may be a field programmable gate array.

[0044] In this embodiment, the control module may be an industrial PC + image acquisition card.

[0045] In this embodiment, the control device may perform a splicing process on the at least two first Hartmann dot maps based on a preset splicing algorithm to obtain a complete second Hartmann dot map.

[0046] Specifically, the preset splicing algorithm may be a centroid offset minimization algorithm.

[0047] The preset stitching algorithm may be a sub-aperture image peak intensity matching algorithm, that is, the peak intensity coordinates of each sub-aperture spot are used for registration.

[0048] The preset stitching algorithm may be an image cross-correlation peak matching algorithm, that is, the overlapping area is regarded as a two-dimensional image block and a cross-correlation operation is performed.

[0049] The preset stitching algorithm may be a spot registration model based on deep learning, which can learn the spatial mapping relationship between adjacent Hartmann dot patterns through end-to-end training.

[0050] In a specific and possible embodiment, the deep learning-based spot registration model may include: The twin convolutional neural network, as a feature extractor, simultaneously processes two input first Hartmann dot maps (pairs of adjacent Hartmann dot maps) through a shared weight structure. The twin convolutional neural network can effectively extract similarities and differences between the two images and identify the relative positions of individual light spots in the wavefront image.

[0051] The feature fusion layer is used to generate spatial transformation parameters. The output features of the twin convolutional neural network are combined 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.

[0052] The spatial transformer network is used to perform differentiable image warping. It can perform affine transformations (rotation, translation, and scaling) on ​​the image, accurately aligning the image at the sub-pixel level. This network allows the image to be precisely deformed according to the predicted spatial transformation parameters, ensuring precise alignment of the light spot position.

[0053] The beneficial effect of this embodiment is that, by introducing the first and second adjustment modules, the height and posture of the sensing module can be precisely adjusted, thereby achieving high-precision wavefront measurement for large-scale beams. Multiple Hartmann dot patterns collected at different heights can be spliced ​​together to generate a larger, complete Hartmann dot pattern, thus overcoming the problem of insufficient wavefront measurement resolution caused by the sensing size limitations of a single Hartmann wavefront sensor. Furthermore, the precise control of the control module and the optimization of the splicing algorithm ensure smoother connections in overlapping areas of the spliced ​​dot patterns, ensuring the accuracy and continuity of the measurement results, thereby improving the accuracy and reliability of wavefront measurement for large-scale beams.

[0054] In some embodiments, the width of the overlapping area satisfies a first preset condition and a second preset condition; wherein, the first preset condition is expressed as the width of the overlapping area is an integer multiple of the pixel size and sub-aperture spacing of the sensing module; the second preset condition is expressed as the width of the overlapping area is an integer multiple of the adjustment accuracy of the first adjustment module.

[0055] This embodiment achieves multiple beneficial effects by setting the width of the overlapping area to meet two constraints at the same time (i.e., the width is an integer multiple of the sensor module pixel size and the sub-aperture spacing, and is an integer multiple of the adjustment accuracy of the first adjustment module). First, the optical level alignment accuracy is significantly improved. The requirement of integer multiple pixel size ensures that the images are aligned to integer pixels during stitching, thereby effectively eliminating the distortion of the wavefront gradient caused by the sub-pixel registration error and greatly reducing the loss of accuracy. Secondly, the compatibility of mechanical control is enhanced. By setting the width of the overlapping area to an integer multiple of the adjustment accuracy of the first adjustment module, it is ensured that the displacement device can naturally form physical alignment when adjusting at the minimum step, avoiding errors caused by cumulative positioning deviations. Finally, the stability of the algorithm is also guaranteed. Ensuring that the width of the overlapping area is an integer multiple of the sub-aperture spacing allows the overlapping area to completely contain the sub-aperture grid unit, maintaining the topological consistency of the wavefront reconstruction grid before and after stitching.

[0056] 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 based on the optimization goal of minimizing the target difference before performing the measurement, so that the second adjustment module automatically adjusts the current posture of the sensing module, thereby making the photosensitive surface of the sensing module parallel to the wavefront profile of the incident light beam; wherein, the target difference is the sum of the center of mass offset of each sub-aperture image in the first Hartmann dot pattern and the preset calibration zero point; wherein, the calibration zero point is represented by the calibration zero point coordinate calibrated by a standard parallel light tube.

[0057] In this embodiment, the control module cooperates with the second adjustment module through an electrical connection to control the working state of the second adjustment module. The second adjustment module is used to adjust the posture of the sensor module, that is, the rotation angle and pitch angle, so that the photosensitive surface of the sensor module remains parallel to the wavefront profile of the light beam.

[0058] Before performing measurement, the control module dynamically generates a control signal based on the optimization goal 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 light beam during measurement.

[0059] In this embodiment, prior to actual wavefront measurement, a calibration step is required to ensure the accuracy of the Hartmann wavefront sensor and the reliability of the wavefront measurement. The calibration process utilizes a standard collimator to ensure the parallelism and distortion-free nature of the light beam, thereby providing a standard, flat wavefront for the wavefront sensor. As will be appreciated, a standard collimator is an optical device that emits a parallel light 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 light beam during measurement.

[0060] During the calibration process, the sensor module must remain parallel to the standard collimator. This means the sensor module's photosensitive surface must be parallel to the wavefront profile of the incident light beam, as only in this condition can the sensor module accurately capture the light spot at the standard position. Under the illumination of the parallel light beam emitted by the standard collimator, the sensor module can measure a set of ideal light spot positions, also known as the calibration zero point. The calibration zero point represents the ideal light spot position that the sensor module should measure when the light beam wavefront is completely flat. By confirming these calibration zero points, the calibration process ensures that the sensor module can accurately capture the wavefront information of the light beam during actual measurement.

[0061] It's also understandable that the calibration process requires ensuring that the sensor module is parallel to the standard collimator. If the two are not parallel, the collected Hartmann dot pattern will no longer be standard and will not accurately reflect the wavefront shape of the light beam. Therefore, the calibration process requires ensuring the parallelism of the sensor module and the standard collimator to ensure that the collected dot pattern reflects undistorted wavefront information.

[0062] This embodiment achieves multiple beneficial effects by electrically connecting the control module to the second adjustment module, dynamically generating a control signal and automatically adjusting the posture of the sensing module based on the optimization goal of minimizing the target difference. First, automatically adjusting the posture of the sensing module ensures that its photosensitive surface is always parallel to the wavefront profile of the incident light beam, greatly improving the accuracy of the wavefront measurement. Secondly, by using the calibration zero point as a reference, the control module can accurately calculate the center of mass offset of each sub-aperture image and perform optimal adjustments, eliminating the system error caused by incorrect posture. Finally, by optimizing the target difference, this method reduces the intervention of manual adjustment, improves the stability and efficiency of the measurement process, and enhances the degree of automation of the system, making it suitable for high-precision wavefront measurement environments.

[0063] In some embodiments, the control module is further configured to perform a splicing process on the at least two first Hartmann dot maps based on a preset splicing algorithm to obtain a complete second Hartmann dot map.

[0064] Specifically, the preset splicing algorithm may be a centroid offset minimization algorithm.

[0065] The preset stitching algorithm may be a sub-aperture image peak intensity matching algorithm, that is, the peak intensity coordinates of each sub-aperture spot are used for registration.

[0066] The preset stitching algorithm may be an image cross-correlation peak matching algorithm, that is, the overlapping area is regarded as a two-dimensional image block and a cross-correlation operation is performed.

[0067] The preset stitching algorithm may be a spot registration model based on deep learning, which can learn the spatial mapping relationship between adjacent Hartmann dot patterns through end-to-end training.

[0068] In a specific and possible embodiment, the deep learning-based spot registration model may include: The twin convolutional neural network, as a feature extractor, simultaneously processes two input first Hartmann dot maps (pairs of adjacent Hartmann dot maps) through a shared weight structure. The twin convolutional neural network can effectively extract similarities and differences between the two images and identify the relative positions of individual light spots in the wavefront image.

[0069] The feature fusion layer is used to generate spatial transformation parameters. The output features of the twin convolutional neural network are combined 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.

[0070] The spatial transformer network is used to perform differentiable image warping. It can perform affine transformations (rotation, translation, and scaling) on ​​the image, accurately aligning the image at the sub-pixel level. This network allows the image to be precisely deformed according to the predicted spatial transformation parameters, ensuring precise alignment of the light spot position.

[0071] This embodiment achieves high-precision dot pattern stitching through a variety of 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 spot registration model based on deep learning. First, by precisely controlling the position of the spot in the overlapping area, the centroid offset minimization algorithm can effectively eliminate the stitching error and ensure the alignment of the image in the overlapping area. Secondly, the sub-aperture image peak intensity matching algorithm uses the peak intensity of the spot for precise registration, further improving the alignment accuracy during the stitching process. The image cross-correlation peak matching algorithm treats the overlapping area as a two-dimensional image block for cross-correlation operations, ensuring that the image remains consistent during the stitching process. Finally, the spot registration model based on deep learning automatically learns the spatial mapping relationship between adjacent Hartmann dot patterns through end-to-end training, so that the model can provide strong robustness in complex measurement environments, especially under the influence of high noise and distortion, further enhancing the accuracy and stability of the stitching algorithm.

[0072] In some embodiments, the first adjustment module is an electric fine-tuning platform, which 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 pattern collected by the sensing module at different heights has the required overlapping area, thereby ensuring the measurement accuracy of the second Hartmann dot pattern after splicing.

[0073] In this embodiment, the electric fine-tuning platform may include: The platform base can be made of metal (aluminum alloy or stainless steel) and is used to carry the second adjustment module (that is, the sensor module is installed on the second adjustment module, and the second adjustment module is set on the platform base, so that the height of the sensor module can be adjusted by the electric fine-tuning platform, and the second adjustment module adjusts the posture of the sensor module). Specifically, the second adjustment module (such as an electric rotating platform) can be fixed or installed on the platform base. The platform base can be connected to the second adjustment module through a mounting hole or a connection interface. The second adjustment module can be firmly mounted on the platform base using screws or threaded interfaces. In addition, during the installation process, the horizontal and vertical positions of the second adjustment module need to be precisely aligned so that the sensor module can accurately rotate and pitch in space when adjusting the posture.

[0074] The screw drive system can use a screw and small stepping motion to control the lifting and lowering of the platform base, and can be driven by a servo motor.

[0075] In order to ensure the smooth movement of the platform base in the vertical direction, the guide rail and slider system can be equipped with a linear guide rail to ensure that the linear motion of the platform base does not deviate from the track and reduce the error caused by friction.

[0076] The position sensor, which can be an optical encoder or a magnetic encoder, detects the platform's current position in real time and feeds this data back to the control module. Based on this feedback, the control module precisely adjusts the servo motor's motion, ensuring the platform base remains within the desired accuracy.

[0077] This embodiment significantly improves the accuracy and automation of the wavefront measurement process by adopting an electric fine-tuning platform as the first adjustment module and electrically connecting it to the control module. During the measurement process, the electric fine-tuning platform can automatically adjust the height of the sensing module based on the control signal sent by the control module, and ensure that the Hartmann dot pattern collected at different heights has the required overlapping area. This automated adjustment not only reduces human operating errors, but also ensures the measurement accuracy of the second Hartmann dot pattern after splicing, thereby ensuring high precision and reliability of wavefront measurement, and is particularly suitable for optical systems that require high-resolution measurement. In addition, through the adjustment of preset accuracy, the system can stably maintain precise alignment, improve the efficiency and consistency of the measurement process, and adapt to complex experimental environments and demanding measurement tasks.

[0078] In some embodiments, the second adjustment module is an electric rotating platform, the sensing module is detachably connected to the electric rotating platform, and 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 light beam, thereby achieving accurate wavefront measurement.

[0079] In this embodiment, the electric rotating platform may include: The dual-axis rotation mechanism is used to provide independent rotational freedom in orthogonal directions, that is, each axis can be controlled independently, allowing precise posture calibration to meet the fine adjustment requirements of the sensor module.

[0080] The drive motor assembly powers the second adjustment module's dual-axis rotation mechanism, enabling highly precise rotational adjustment. Based on instructions from the control module, the drive motor assembly precisely adjusts the dual-axis rotation mechanism's motion to ensure the sensor module's rotation angle meets the preset requirements.

[0081] The angle feedback system may include an optical encoder. The optical encoder monitors the position of the rotating shaft in real time and converts the actual rotation angle into a digital signal to feed back to the control module.

[0082] In this embodiment, the electric rotating platform can be fixed or installed on the platform base of the first adjusting module, so as to achieve the coordination of the vertical displacement adjustment function of the electric rotating platform and the first adjusting module.

[0083] This embodiment achieves highly flexible and accurate wavefront measurement by adopting a detachable connection between an electric rotating platform and the sensor module. The electric rotating platform cooperates with the vertical displacement adjustment function of the first adjustment module to accurately control the rotation angle and pitch angle of the sensor module, ensuring that the photosensitive surface of the sensor module is always parallel to the wavefront profile of the incident light beam. This design greatly improves the accuracy and stability of wavefront measurement. Through automated posture adjustment, not only the error of manual intervention is reduced, but also the efficiency and repeatability of the measurement process are improved. In addition, the detachable connection method of the electric rotating platform makes the system more flexible and facilitates module replacement and maintenance, thereby further enhancing the reliability and adaptability of the system.

[0084] like Figure 2 As shown, this embodiment provides a control method for 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 pattern of an incident light beam having a target size, the target size being larger than a sensing size of the sensing module; the first adjustment module is used to adjust the height of the sensing module; and the second adjustment module is used to adjust the posture of the sensing module. The method comprises: Step S12: receiving at least two first Hartmann dot maps collected by the sensing module at different heights; wherein the two first Hartmann dot maps collected at adjacent heights have an overlapping area of ​​a preset size.

[0085] Step S14: performing a splicing process on the at least two first Hartmann dot maps to obtain a complete second Hartmann dot map; wherein the size of the second Hartmann dot map is larger than the size of the first Hartmann dot map.

[0086] The control method provided in this embodiment can achieve high-precision measurement of the wavefront of large-scale light beams by precisely controlling the height and posture adjustment of the sensor module. First, the control method receives at least two Hartmann dot patterns acquired at different heights and ensures that there is an overlapping area of ​​a preset size between these dot patterns, thereby ensuring the spatial continuity of the complete stitched image. Then, by stitching these dot patterns together, a larger complete Hartmann dot pattern is generated, thereby achieving accurate measurement of the wavefront of large-scale light beams. This method can overcome the problem of reduced accuracy caused by the sensing size limitations of the sensor module in traditional measurements, improve the quality of the stitched image, and ensure the accuracy and reliability of the wavefront measurement.

[0087] In this embodiment, the step of performing a splicing process on the at least two first Hartmann dot maps to obtain a complete second Hartmann dot map includes: Step S142: for the initial first Hartmann dot map in the received first Hartmann dot map, adjust each sub-aperture image in the overlapping area thereof so that the sum of the centroid offsets of each sub-aperture image and the preset calibration zero point is minimized.

[0088] Step S144: For the first Hartmann dot map other than the initial first Hartmann dot map, adjust the sub-aperture images in the overlapping area thereof so that the centroid offset of the sub-aperture images in the corresponding overlapping area between the current first Hartmann dot map and the previous first Hartmann dot map is minimized.

[0089] In this embodiment, it is understood that when two Hartmann dot patterns are captured by adjusting their height, an overlapping region exists between the upper and lower Hartmann dot patterns. This region contains the shared portion of the adjacent dot patterns. This overlapping region is critical for stitching accuracy, as it contains the light spots or sub-aperture images that require alignment.

[0090] In this embodiment, the goal is to adjust the overlapping area between the current first Hartmann dot map and the previous first Hartmann dot map so as to minimize the displacement of the centroid of the sub-aperture images in the corresponding overlapping area between the two dot maps. For example, if the current Hartmann dot map is the second Hartmann dot map, the corresponding area may be the overlapping area at the top of the second Hartmann dot map. The displacement between the centroid of the sub-aperture image in the overlapping area at the top of the second Hartmann dot map and the centroid of the sub-aperture image in the overlapping area at the bottom of the first Hartmann dot map (the initial image) needs to be minimized.

[0091] In this embodiment, the center of mass offset refers to the displacement between the center of mass positions of two sub-aperture images. In the overlapping area, each sub-aperture image has a center of mass position, and the offset represents the distance between the center of mass of the current image and the center of mass of the same position in the previous image. In order to achieve accurate stitching, this offset needs to be minimized. By precisely controlling the position of the current dot pattern, the center of mass offset of the sub-aperture image in the overlapping area between the current dot pattern and the previous dot pattern is minimized. The current dot pattern can be translated or rotated to ensure that it is aligned with the sub-aperture image in the previous dot pattern. After adjustment, the overlapping area of ​​the current dot pattern and the previous dot pattern will be seamlessly connected, ensuring that the stitched image can retain complete wavefront information and the spot position is accurately aligned.

[0092] This embodiment optimizes the alignment accuracy of the spot position 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 pattern, the centroid offset of each sub-aperture image and the preset calibration zero point is minimized, thereby ensuring the precise starting position of the stitched image. Then, for other first Hartmann dot patterns, by adjusting the sub-aperture images in their overlapping areas, the deviation between adjacent dot patterns is minimized to the greatest extent, ensuring the precise docking of the spot positions of different dot patterns in the overlapping area. This method significantly improves the accuracy of the complete second Hartmann dot pattern after stitching through fine image alignment processing, ensuring high precision and high reliability of wavefront measurement, and can provide more stable and accurate stitching results, especially in high-precision optical measurement applications.

[0093] According to an embodiment of the present invention, a laser system is provided, including the above-mentioned light beam wavefront measurement device.

[0094] In this embodiment, the laser system may be a laser system used in a high-energy laser manufacturing scenario.

[0095] In this embodiment, the laser system may be a laser system used in a semiconductor lithography scenario.

[0096] In this embodiment, the laser system may be a laser system in a medical laser treatment device scenario.

[0097] In this embodiment, the laser system may include not only the above-mentioned beam wavefront measurement device, but also a beam transmission module, a wavefront adjustment module, optical elements and other auxiliary devices.

[0098] In one possible and specific embodiment, a large-scale rectangular beam wavefront measurement device and method are provided. This embodiment adjusts the height of a Hartmann wavefront sensor by adjusting a high-precision displacement adjustment device. Hartmann dot patterns corresponding to the rectangular beam are collected multiple times. Adjacent dot patterns have overlapping areas. These dot patterns are then stitched together to form a complete Hartmann dot pattern corresponding to the rectangular beam. This dot pattern is used for wavefront reconstruction, achieving high-precision wavefront measurement of large-scale rectangular beams.

[0099] See also 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; The Hartmann wavefront sensor is used to collect the Hartmann dot pattern; The high-precision displacement adjustment device is used to adjust the height of the Hartmann wavefront sensor; The two-dimensional adjustment platform is used to adjust the rotation angle and pitch angle of the Hartmann wavefront sensor.

[0100] It should be noted here 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; It should be further explained that it is also necessary to adjust the two-dimensional adjustment platform so that the photosensitive surface of the Hartmann wavefront sensor is parallel to the wavefront profile of the rectangular light beam. The judgment method is that the sum of the centroid offsets ∑i,j((xij-xij0)+(yij-yij0)) of the sub-aperture image of the Hartmann dot pattern in the middle area relative to the calibration zero point (xij0, yij0) is minimized, that is, ∑i,j((xij-xij0)+(yij-yij0))=min,i=1,2,…,I,j=1,2,…,J, where I and J are the number of rows and columns of the sub-aperture image of the Hartmann dot pattern, respectively; xij, yij represent the centroid coordinates of the sub-aperture light spot in the i-th row and j-th column of the Hartmann dot pattern.

[0101] It should be further explained that the calibration zero point (xij0, yij0) is the coordinate of the centroid position of the sub-aperture where the tilt aberration of the Hartmann wavefront sensor is minimized on the standard collimator.

[0102] Specifically, the Hartmann wavefront sensor includes a microlens array and a detection camera, but is not limited to the above sensor form, as long as the sensor can reconstruct the wavefront.

[0103] See also Figure 4 、 Figure 5 and Figure 6This embodiment provides a large-size rectangular beam wavefront measurement method, which adjusts the high-precision displacement adjustment device to change the height of the Hartmann wavefront sensor to obtain Hartmann dot patterns (1, 2, ..., n) corresponding to the areas of multiple rectangular beams, such as Figure 4 As shown; It should be noted that adjacently collected dot patterns have an overlapping area of ​​fixed width. All dot patterns are spliced ​​into a complete Hartmann dot pattern corresponding to a rectangular beam through the overlapping area. This dot pattern is used for wavefront reconstruction, such as Figure 5 As shown; The width h of the overlapping area must be an integer multiple of the Hartmann wavefront sensor pixel size s and the subaperture spacing a, that is, h%s=0 and h%a=0, to ensure that the dot pattern moves by integer pixels and integer aperture numbers, and h is an integer multiple of the adjustment accuracy δ of the high-precision displacement adjustment device, that is, h%δ=0, to ensure that during the process of adjusting the height of the high-precision displacement adjustment device, the intensity distribution of each subaperture image in the overlapping area on the detection camera pixel is basically consistent; like Figure 6 ,The minimum centroid offset algorithm for image stitching includes the following steps: 1. Reconstruct the grid and adjust the Hartmann lattice Figure 1 , so that the sum of the centroid offsets (Δx1ij, Δy1ij) relative to the calibration zero point (xij0, yij0) is minimized, that is, ∑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 Hartmann lattice sub-aperture image in the overlapping area respectively; 2. Adjust the Hartmann lattice Figure 2 ,make Figure 2 The subaperture images in the overlapping area are relative to Figure 1 The centroid offset of the sub-aperture images in the overlapping area is the smallest, that is, ∑i,j(Δx2ij+Δy2ij-Δx1ij-Δy1ij)=min,i=1,2,…,M, j=1,2,…,N; 3. Repeat step 2 until the Hartmann dot pattern N is spliced.

[0104] It is understandable that during the calibration phase, the two-dimensional adjustment platform adjusts the rotation and pitch angles of the Hartmann wavefront sensor, making the sensor's photosensitive surface as parallel as possible to the beam wavefront profile, so that the Hartmann dot pattern sub-aperture image in the middle area corresponds to the calibration zero point position, and the center of mass offset is minimized. Specifically: This is to eliminate installation errors and ensure that the Hartmann wavefront sensor is correctly aligned with the wavefront of the light beam so that the measurement data is accurate. This step is sensor alignment, and the accuracy of the measurement results can be ensured by adjusting the position and angle of the sensor.

[0105] The wavefront sensor is precisely adjusted using a two-dimensional adjustment platform to ensure that the center of mass of the light spot is aligned as closely as possible to the calibration zero point. This minimizes errors caused by inaccurate installation and ensures the accuracy of the measurement data.

[0106] In this process, the centroid offset minimization algorithm ensures that the calibrated Hartmann dot pattern subaperture images reach the ideal position.

[0107] Image stitching involves combining multiple acquired dot patterns into a complete rectangular beam wavefront image. The key to this step is handling the overlapping areas between the images to ensure the accuracy of the stitching result. By stitching multiple dot patterns together, the center of mass offset of the overlapping areas is minimized to produce a seamless wavefront image.

[0108] By adjusting the position of each dot pattern (rather than adjusting the sensor itself), the centroid offset of the sub-aperture images in the overlapping area between adjacent images is minimized. During the image stitching process, the offset minimization algorithm aims to ensure the alignment accuracy between each spot, ensuring that the spots in the stitched image are free of significant errors.

[0109] In other words, it is the position of the image itself that is adjusted here, not the angle or position of the sensor.

[0110] The calibration phase focuses on sensor installation accuracy, ensuring that the captured dot pattern accurately reflects the wavefront information of the light beam. Image stitching focuses on the accuracy of image synthesis, ensuring that the wavefront images of multiple areas can be seamlessly stitched together to obtain a complete wavefront image.

[0111] It should be further explained that, in this embodiment, a minimum offset algorithm is used to stitch images, and other image matching algorithms such as sub-aperture image peak intensity matching, image cross-correlation peak matching algorithm and artificial intelligence may also be used, that is, including but not limited to the above-mentioned algorithm or other similar algorithms.

[0112] Specifically, the method of reconstructing the wavefront using the complete spliced ​​Hartmann dot pattern can be specifically set according to actual needs. The present invention does not impose any specific restrictions on it, as long as it can be applied to the large-size rectangular beam wavefront measurement method proposed in the present invention.

[0113] 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, a memory, a 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 the one or more processors, and the one or more programs are configured to perform the method described in the aforementioned method embodiment.

[0114] According to an embodiment of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a computer, the computer executes the method described in any one of the above embodiments.

[0115] According to an embodiment of the present invention, a computer program product comprising instructions is further provided. When the instructions are executed by a computer, the computer is enabled to perform a method in any one of the above embodiments.

[0116] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0117] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, and this embodiment will not be described in detail here.

[0118] The serial numbers of the above embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0119] In the above embodiments of the present application, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0120] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A light beam wavefront measurement device, characterized in that: include: A sensing module configured to collect a first Hartmann dot pattern of an incident light beam having a target size, wherein the target size is larger than a sensing size of the sensing module; a first adjusting module, configured to adjust the height of the sensing module; a second adjustment module, configured to adjust the posture of the sensing module; A control module is electrically connected to at least the sensing module and is configured to receive at least two first Hartmann dot patterns acquired by the sensing module at different heights, acquire two first Hartmann dot patterns at adjacent heights, and obtain an overlapping area of ​​a preset size; then perform a splicing process 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 that of the first Hartmann dot pattern.

2. The light beam wavefront measurement device according to claim 1, characterized in that: The width of the overlapping area satisfies a first preset condition and a second preset condition; wherein, the first preset condition is expressed as the width of the overlapping area is an integer multiple of the pixel size of the sensing module and the sub-aperture spacing; the second preset condition is expressed as the width of the overlapping area is an integer multiple of the adjustment accuracy of the first adjustment module.

3. The light beam wavefront measurement device according to claim 1, characterized in that: The control module is also electrically connected to the second adjustment module. The control module is also configured to dynamically generate a control signal and send it to the second adjustment module based on the optimization goal of minimizing the target difference before performing the measurement, so that the second adjustment module automatically adjusts the current posture of the sensor module, thereby making the photosensitive surface of the sensor module parallel to the wavefront profile of the incident light beam; wherein, the target difference is the sum of the center of mass offset of each sub-aperture image in the first Hartmann dot pattern and the preset calibration zero point; wherein, the calibration zero point is represented by the calibration zero point coordinate calibrated by a standard parallel light tube.

4. The light beam wavefront measurement device according to claim 1, characterized in that: The control module is further configured to perform a splicing process on the at least two first Hartmann dot maps based on a preset splicing algorithm to obtain a complete second Hartmann dot map.

5. The light beam wavefront measurement device according to claim 1, characterized in that: The first adjustment module is an electric fine-tuning platform, which is electrically connected to the control module and is configured to automatically adjust the height of the sensor 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 sensor module at different heights has the required overlapping area, thereby ensuring the measurement accuracy of the second Hartmann dot pattern after splicing.

6. The light beam wavefront measurement device according to claim 1, characterized in that: The second adjustment module is an electric rotating platform, and the sensor 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 sensor module so that the photosensitive surface of the sensor module is parallel to the wavefront profile of the incident light beam, thereby achieving accurate wavefront measurement.

7. A control method for a beam wavefront measurement device, characterized in that: The light beam wavefront measurement device includes 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 pattern of an incident light beam having a target size, where the target size is larger than a sensing size of the sensing module; the first adjustment module is used to adjust the height of the sensing module; and the second adjustment module is used to adjust the posture of the sensing module. The method includes: receiving at least two first Hartmann dot patterns acquired by the sensing module at different heights; wherein the two first Hartmann dot patterns acquired at adjacent heights have an overlapping area of ​​a preset size; A stitching process is performed on the at least two first Hartmann dot maps to obtain a complete second Hartmann dot map; wherein the size of the second Hartmann dot map is larger than the size of the first Hartmann dot map.

8. The control method of a beam wavefront measurement device according to claim 7, characterized in that: The step of performing splicing processing on the at least two first Hartmann dot maps to obtain a complete second Hartmann dot map includes: For the initial first Hartmann dot map in the received first Hartmann dot map, adjust each sub-aperture image in the overlapping area thereof so that the sum of the centroid offsets of each sub-aperture image and a preset calibration zero point is minimized; For the first Hartmann dot map other than the initial first Hartmann dot map, the sub-aperture images in the overlapping areas are adjusted so that the centroid offset of the sub-aperture images in the corresponding overlapping areas of the current first Hartmann dot map and the previous first Hartmann dot map is minimized.

9. A laser system, characterized in that: The invention comprises a light beam wavefront measuring device as described in any one of claims 1 to 6.

10. An electronic device, characterized in that: include: a memory, and one or more processors communicatively coupled to the memory; The memory stores instructions that can be executed by the one or more processors, and the instructions are executed by the one or more processors to enable the one or more processors to implement a control method for a beam wavefront measurement device according to any one of claims 7 or 8.

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