Seidel aberration sensor for optical imaging system measurement

Abstract

The invention provides a Seidel aberration sensor for optical imaging system measurement, and relates to the technical field of optical measurement. The sensor comprises a lighting system, a customized dot matrix target, an optical system to be measured, a collimation optical system and a Seidel aberration sensor, wherein the Seidel aberration sensor consists of a micro-lens array and a camera. Quantitative measurement of five kinds of Seidel aberrations including primary spherical aberration, coma aberration, astigmatism, field curvature and distortion is realized by presetting and calibrating a customized dot matrix target and calibrating an exclusive calibration system of a Seidel aberration sensor in combination with mass center offset calculation of a sensing image, global view multi-point wavefront reconstruction and Zernike polynomial distribution coefficients. The method does not need a complex high-resolution image registration algorithm and double-dimension reduction aberration coefficient matrix calculation, is high in measurement precision and efficiency, can avoid a high-frequency evaluation blind area and error accumulation, is suitable for optical performance evaluation of various imaging systems with large visual field and high flux, and improves the quality control capability and the assembly efficiency in the production process of the optical system.

Description

Technical Field

[0001] This invention belongs to the field of optical measurement technology, and more specifically, relates to a Seidel aberration sensor for measurement in optical imaging systems. Background Technology

[0002] Aberrations are a core evaluation metric in optical design, directly impacting the theoretical performance prediction of imaging systems. Among these, the five primary monochromatic aberrations—spherical aberration, coma, astigmatism, field curvature, and distortion (i.e., Seidel aberrations)—have the most critical influence on imaging results. Rapid and accurate Seidel aberration measurement is a core requirement for improving the production control capabilities and assembly efficiency of optical components and imaging systems.

[0003] Current mainstream aberration measurement techniques have many shortcomings:

[0004] Firstly, relying on ISO standards and their derivative technologies (such as ISO12233, ISO17850, etc.), the imaging quality can be indirectly judged by analyzing the target imaging results to obtain the spatial frequency response function and evaluating distortion variables. However, the sampling characteristics of digital imaging systems result in an evaluation blind zone for the high-frequency modulation transfer function outside the Nyquist limit, and multiple independent measurements are prone to additional errors due to differences in operating conditions, making it difficult to fully reflect the overall aberration performance of the system.

[0005] Secondly, although interferometers can achieve wavefront reconstruction with subwavelength accuracy, they are highly sensitive to the environment and are only suitable for surface inspection of components or measurement of a single field of view. They also rely on precision reference components and stable light sources, which limits their applicable scenarios.

[0006] Third, while the Shaker-Hartmann wavefront sensor has the advantage of fast response, it can only acquire the global average wavefront under extended light source conditions, and the Seidel coefficient inversion in point light source mode depends on absolute position determination, resulting in large errors; when combined with a mechanical motion device to achieve full field of view scanning, it is easy to cause the accumulation of measurement errors.

[0007] Fourth, existing related patent technologies (such as Chinese patent with publication number CN117554040A: a method and device for measuring aberrations of optical elements or imaging systems) can directly measure the complete aberration information of the imaging system, but do not specify the mask template for imaging testing, require reliance on complex high-resolution image registration algorithms, and do not provide calculation formulas for Seidel aberrations other than distortion, the device calibration process is missing, and the calculation process is cumbersome.

[0008] In summary, existing technologies cannot achieve rapid, accurate, and comprehensive reconstruction of all Seidel aberrations, making it difficult to meet the demand for efficient evaluation of optical system performance in actual production. Therefore, a targeted technical solution is urgently needed to address these issues. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a Seidel aberration sensor for measurement in optical imaging systems. This sensor solves the technical problems of existing aberration measurement techniques, such as the inability to quickly and accurately reconstruct all five Seidel aberrations, reliance on complex algorithms, lack of clear test mask and device calibration processes, and cumbersome calculations.

[0010] A Seidel aberration sensor for measurement in an optical imaging system includes an illumination system, a custom dot matrix target, an optical system to be measured, a collimating optical system, and a Seidel aberration sensor.

[0011] The optical system to be measured is equipped with an aperture stop, and the Seidel aberration sensor includes a microlens array and a camera imaging chip; the customized dot matrix target is located on the target plane of the optical system to be measured.

[0012] The front focal plane of the collimating optical system is located on the target image plane of the customized dot matrix target in the optical system under test; the microlens array plane is located on the conjugate plane of the aperture stop of the optical system under test and the rear end of the optical system under test and the collimating optical system; the camera imaging chip is located on the rear focal plane of the microlens array.

[0013] By combining the calibration results of the customized dot matrix target and the Seidel aberration sensor with the centroid offset calculation of the sensed image, the measurement of all Seidel aberrations, including primary spherical aberration, coma, astigmatism, field curvature, and distortion, can be achieved.

[0014] Preferably, the customized dot matrix target is made of metal or glass sheet and formed into a hole array structure by laser, etching or electroplating processes.

[0015] Preferably, the calibration process of the customized dot matrix target includes: taking a magnified image of the customized dot matrix target using a commercial microscope, and calculating the absolute position coordinates of the centroid of each light point on the dot matrix target by combining the magnification of the commercial microscope.

[0016] Preferably, the microlens array of the Seidel aberration sensor is used to discretize the wavefront phase, and the camera imaging chip is used to acquire sub-images corresponding to each microlens, wherein the sub-images are of a dot matrix structure.

[0017] Preferably, it also includes a Seidel aberration sensor calibration system, which consists of a multimode fiber optic patch cord, an LED light source, and a collimating lens;

[0018] The light-emitting end face of the multimode fiber optic patch cord is located at the front focal face of the collimating lens.

[0019] Real-time feedback adjustment using a commercial wavefront sensor ensures the parallelism of the collimated beam, and the width of the collimated beam covers the working surface of the Seidel aberration sensor.

[0020] Preferably, the measurement steps for Seidel aberration include:

[0021] S1: Acquire the customized dot matrix target sensing image captured by the Seidel aberration sensor, and determine the center position and beam width of the incident beam based on the overall energy distribution of the image;

[0022] S2: Segment the sub-images corresponding to each microlens and calculate the centroid position of the lattice light points in the complete sub-image within the beam range;

[0023] S3: Align the calibration results of the Seidel aberration sensor with the actual microlens, align the calibration results of the customized dot matrix target with all target sub-images, and calculate the offset between the center spot of each dot matrix target in each microlens and the centroid of the actual spot.

[0024] S4: Based on the offset, reconstruct the wavefront distribution covering multiple points in the global field of view. After transforming the wavefront distribution using the standard Zernike polynomial, substitute it into the Seidel aberration calculation formula to obtain all Seidel aberrations.

[0025] Preferably, in step S4, the wavefront reconstruction adopts an independent reconstruction method;

[0026] The centroid of each group of light spots is based on:

[0027] The Moment-based Space-variant Shack–Hartmann wavefront reconstruction method achieves wavefront inversion, obtaining wavefront distributions covering multiple points within the global field of view. Define the normalized coordinates of the object / image plane as follows: The normalized coordinates of the pupil surface are The corresponding polar coordinate system is:

[0028]

[0029] Preferred wavefront distribution Using Zernike polynomials Expand:

[0030] Zernike coefficient Depending on the view coordinates Distribution Perform polynomial factorization:

[0031] ;

[0032] The preferred formula for calculating Seidel aberrations is:

[0033] Ball difference: ;

[0034] Coma: ;

[0035] Like scattered: ;

[0036] Stage music:

[0037] distortion: .

[0038] Preferably, the Seidel aberration measurement is suitable for large field-of-view, high-throughput imaging systems, and can avoid the evaluation blind zone of the high-frequency modulation transfer function outside the Nyquist limit. The aperture array specifications of the customized dot matrix target can be adjusted according to the parameters of the optical system to be measured and the Seidel aberration sensor, with the aperture spacing ranging from 0.01 to 50 mm and the aperture diameter ranging from 0.001 to 10 mm.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] Breaking through the high-frequency evaluation blind zone and covering the entire field of view for aberration measurement: This invention avoids the evaluation blind zone outside the Nyquist limit caused by the sampling characteristics of digital imaging systems through the collaborative design of customized dot matrix targets and Seidel aberration sensors. At the same time, it can directly realize multi-point wavefront reconstruction of the global field of view without the need for mechanical motion devices to scan, and comprehensively capture the spatial distribution characteristics of aberrations with the position of the field of view and the meridional / sagittal direction, thus solving the problem of incomplete measurement by traditional techniques.

[0041] Reduce measurement errors and improve result accuracy: The dedicated calibration system (including dot matrix target calibration and sensor calibration) compensates for target processing errors and sensor errors in advance, avoiding the superposition of errors due to differences in working conditions from multiple independent measurements. At the same time, through precise calculation of coordinate mapping and centroid offset, it reduces the accumulation of errors in the wavefront reconstruction process, and the measurement repeatability and accuracy are significantly better than existing technologies.

[0042] Simplify the algorithm process and improve measurement efficiency: Clearly specify the customized dot matrix target and its calibration method, eliminating the need to rely on complex high-resolution image registration algorithms; reconstruct the aberration reconstruction algorithm framework, eliminating the tedious calculation of the double-dimensional aberration coefficient matrix, and combine it with the standardized Seidel aberration calculation formula, which greatly shortens the data processing time and improves the overall efficiency of aberration measurement.

[0043] Achieving full-range Seidel aberration quantification: For the first time, calculation formulas for all five Seidel aberrations—primary spherical aberration, coma, astigmatism, field curvature, and distortion—are clearly given, overcoming the shortcomings of existing technologies that can only measure some aberrations or cannot quantify them, and providing complete data support for the comprehensive performance evaluation of optical systems.

[0044] Wide range of applications and strong compatibility: This invention does not rely on special light sources or precision reference elements, and has relatively relaxed requirements for the measurement environment. It can be adapted to aberration detection of various imaging systems such as large field of view and high throughput. At the same time, the aperture array specifications of the customized dot matrix target can be flexibly adjusted according to the parameters of the optical system to be measured, which has strong practicality and compatibility. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the simulation results of the effect of Seidel aberration on imaging in this invention;

[0046] Figure 2 This is a schematic diagram of the working principle of the present invention;

[0047] Figure 3 This is a schematic diagram of the Seidel aberration sensor calibration system in this invention;

[0048] Figure 4 This is a schematic diagram of the calibration results of the customized dot matrix target in this invention;

[0049] Figure 5 This is a schematic diagram of the calibration results of the Seidel aberration sensor in this invention;

[0050] Figure 6 This invention describes the acquisition, localization, segmentation, position calculation, and coordinate mapping of the sensor image in the Seidel aberration detector working mode. The small image on the right is a magnified view of the corresponding position in the left image.

[0051] Figure 1 In the diagram, the correspondence between the component names and the attached drawing numbers is as follows: 1. Illumination system; 2. Custom dot matrix target; 3. Optical system to be measured; 4. Collimating optical system; 5. Seidel aberration sensor; 11. Multimode fiber optic patch cord; 12. LED light source; 21. Target image plane; 31. Aperture stop; 51. Microlens array; 52. Camera imaging chip; 6. Collimating lens. Detailed Implementation

[0052] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0053] Please see Figures 1-6 This invention provides a Seidel aberration sensor for measurement in optical imaging systems. It strictly follows the system structure relationship and working principle to ensure measurement accuracy and repeatability. The following description is based on the structural designation and specific parameters.

[0054] System setup and component parameter determination:

[0055] Component selection and parameter setting:

[0056] Illumination System 1: Employs a diffused light illuminator with an output light intensity uniformity of ≥90%, a peak wavelength of 458 nm, and a spectral range of approximately 20 nm, used to uniformly illuminate the customized dot matrix target 2.

[0057] Customized dot matrix target 2: Made of 0.05mm thick stainless steel sheet, with a 7×7 hole array processed by photolithography and etching process, with a hole spacing of 0.2mm and a hole diameter of 0.02mm.

[0058] The optical system to be measured 3: Taking the imaging system of lens 1 (focal length 25.4mm, 1-inch plano-convex lens) and lens 2 (focal length 180mm, 2-inch cemented doublet achromatic lens) as an example, its object-side field of view is 0.849mm, the aperture stop 31 has a diameter of 7mm, and is fixed at 24.89mm behind lens 1.

[0059] Collimation optical system 4: A 2-inch cemented doublet achromatic lens with a focal length of 300mm is selected, and the beam collimation accuracy is guaranteed by a commercially available Shaker-Hartmann wavefront sensor.

[0060] Seidel aberration sensor 5: The microlens array 51 uses a microlens array with a focal length of 13.67453mm, a single microlens diameter of 0.5mm, an array size of 30×30, and a size of 15mm×15mm. The single microlens aperture is 0.5mm. The camera imaging chip 52 uses a CMOS chip with a pixel size of 2.5μm×2.5μm and a resolution of 5120×5120, with a frame rate of 28fps, to ensure the clarity and speed of sub-image acquisition.

[0061] Calibration system components: Multimode fiber optic patch cord 11 with a numerical aperture of 0.37, a fiber core diameter of 0.4 mm, and a length of 2 meters; LED light source 12 with an output wavelength of 532 nm (peak) and an optical power of ≥20 mW; Collimating lens is a 2-inch cemented doublet achromatic lens with a focal length of 200 mm, and beam collimation accuracy is ensured by a commercial Shaker-Hartmann wavefront sensor or interferometer.

[0062] Structural position assembly:

[0063] A custom dot matrix target 2 is fixed on the target plane (dashed line position) of the optical system 3 to be measured. The center of the target coincides with the optical axis of the optical system 3 to be measured, and the positional deviation is ≤0.005mm.

[0064] The front focal plane of the collimating optical system 4 coincides with the target image plane 21 (dashed line position) of the customized dot matrix target 2 in the optical system to be measured 3, and the coaxiality of the optical axis of the collimating optical system 4 and the optical system to be measured 3 is ≤0.005mm.

[0065] The plane of the microlens array 51 is located on the conjugate plane of the aperture stop 31 after passing through the rear end of the optical system 3 to be measured and the collimating optical system 4, and the center of the microlens array 51 is aligned with the optical axis.

[0066] The camera imaging chip 52 is fixed to the back focal plane of the microlens array 51. The chip plane is parallel to the plane of the microlens array 51 through a fine-tuning mechanism, and the parallelism deviation is ≤0.001mm.

[0067] Calibration process:

[0068] Calibration of Customized Matrix Target 2:

[0069] The customized dot matrix target 2 was placed on the stage of a commercial microscope. The microscope used was a bright-field microscope with a magnification of 2×, a resolution of 2.5μm, and a central field distortion of ≤0.1%. The microscope was connected to a computer.

[0070] Capture a magnified image (2× magnification) of the customized dot matrix target 2. Extract the centroid of the light spot for each hole using image analysis algorithms or software (such as ImageJ) to obtain the absolute position coordinates of the centroid of each light spot. With an accuracy of ≤0.05μm, the coordinate data is stored in the computer's memory.

[0071] Calibration of Seidel aberration sensor 5:

[0072] Set up the calibration system: fix the light-emitting end face of the multimode fiber optic patch cord 11 to the front focal plane of the collimating lens, connect the LED light source 12 to the input end of the multimode fiber optic patch cord 11, and align the output end of the collimating lens with the light-incident surface of the Seidel aberration sensor 5.

[0073] System calibration: Turn on LED light source 12, monitor the parallelism of collimated beam in real time using commercial Shaker-Hartmann wavefront sensor (accuracy λ / 200, 532nm), adjust the position of collimating lens to ensure that the mean square error of the outgoing beam wavefront is ≤0.02λ; adjust the position of calibration system so that the collimated beam completely covers the working surface of Seidel aberration sensor 5 (the entire area of ​​microlens array 51).

[0074] Calibration Image Acquisition and Processing: The Seidel aberration sensor 5 captures calibration images, and the centroid position of the light spot corresponding to each microlens (marked with a green cross) is extracted by the image algorithm as the sensor calibration coordinates and stored in the computer memory. The calibration repeatability is ≤0.05μm.

[0075] Seidel aberration measurement steps:

[0076] Sensor image acquisition:

[0077] Illumination system 1 is turned on. After the light intensity stabilizes (fluctuation ≤1%), Seidel aberration sensor 5 captures the sensing image of the customized dot matrix target 2 after passing through the optical system to be measured 3 and collimating optical system 4. Images are collected 3 times at different exposure times and fused into a high dynamic range image for subsequent processing.

[0078] Image localization and segmentation:

[0079] Based on the overall energy distribution of the image, the center position of the incident beam (marked by a yellow pentagram) and the beam width (marked by a yellow circle) are determined by a threshold segmentation algorithm. The beam width must cover at least 21×21 microlens regions.

[0080] A grid segmentation algorithm is used to segment the sensor image into sub-images corresponding to individual microlenses according to the arrangement of the microlens array 51. The segmentation accuracy is ≤1 pixel, ensuring that each sub-image is extracted independently.

[0081] Centroid Calculation and Coordinate Mapping:

[0082] For the complete sub-image within the beam range, the centroid position (marked by a red cross) of each dot matrix spot is calculated using a Gaussian fitting algorithm with a calculation accuracy of ≤0.1 pixels.

[0083] Coordinate mapping operation:

[0084] Align the calibration coordinates (green cross) of the Seidel aberration sensor 5 with the actual microlens array 51 so that the centroid of the array center spot of the microlens sub-image where the incident beam center is located coincides with the calibration coordinate center.

[0085] Align the calibration coordinates (blue asterisk) of the custom dot matrix target 2 with all target sub-images so that the center spot of the custom dot matrix target 2 coincides with the center of the calibration coordinates of the corresponding microlens.

[0086] Centroid shift and wavefront reconstruction:

[0087] Calculate the offset between the center spot (blue asterisk) of each group of customized dot matrix targets 2 in each microlens and the centroid of the actual light spot (red cross) to obtain the offset distribution across the entire field of view.

[0088] Based on offset distribution:

[0089] The Moment-based space-variant Shack–Hartmann wavefront reconstruction method was used to analyze each group of light spots. The wavefront is obtained by independently reconstructing the centroid distribution. This allows us to obtain the wavefront distribution covering multiple points within the global field of view. ,in For the object-image plane coordinates, For pupil plane coordinates, the corresponding polar coordinate system is:

[0090]

[0091] Seidel aberration calculation:

[0092] wavefront distribution Through standard Zernike polynomials Expand to obtain the Zernike coefficient. ,in The number of terms in the polynomial (the first 11 terms are used in this embodiment):

[0093] Among them, the standard Zernike polynomial (Noll, RJ, Zernike Polynomials and Atmospheric Turbulence, Journal of the Optical Society of America, 1976):

[0094]

[0095]

[0096] Zernike coefficient Depending on the view coordinates Distribution Perform polynomial factorization:

[0097] ;

[0098] Then, substitute the decomposition coefficients into the Seidel aberration calculation formula:

[0099] Ball difference: ;

[0100] Coma: ;

[0101] Like scattered: ;

[0102] Stage music:

[0103] distortion: .

[0104] Output the quantization results of all five Seidel aberrations, in wavelength (λ=458nm).

[0105] Data processing and result output:

[0106] Data verification: Confirm that the calculated centroid positions match the corresponding light spots in the sensor images to ensure data validity; wavefront reconstruction uses a mode method based on Zernike polynomials to reduce the impact of noise.

[0107] Results output: Seidel aberration distribution map, wavefront distribution at each location (including root mean square (RMS) value and peak-to-valley (PV) value), MTF curve at each location (including meridional / sagittal directions), and MTF variation curve with field of view. Data formats supported include CSV and image formats (PNG).

[0108] Measurement repeatability verification: The same optical system to be measured was measured 5 times repeatedly, and the coefficient of variation of each aberration measurement result was calculated to be ≤1% to ensure measurement stability.

[0109] Precautions:

[0110] The measurement environment needs to be controlled for temperature (20±2℃), humidity (30%-50%), and vibration isolation platform, while avoiding airflow disturbances to reduce the impact of the environment on measurement accuracy.

[0111] The custom dot matrix target 2 and the Seidel aberration sensor 5 are recalibrated regularly (every 3 months) to compensate for errors caused by component aging.

[0112] When replacing the optical system 3 to be measured, the aperture array specifications of the customized dot matrix target 2 and the position of the collimating optical system 4 need to be adjusted according to its focal length and field of view to ensure compatibility.

[0113] In summary, this invention constructs a complete and efficient Seidel aberration measurement scheme through the collaborative design of the illumination system 1, the customized dot matrix target 2, the optical system to be measured 3, the collimating optical system 4, and the Seidel aberration sensor 5, combined with a dedicated calibration system consisting of a multimode fiber optic patch cord 11 and an LED light source 12. Through the precise calibration of the customized dot matrix target 2 and the system calibration of the Seidel aberration sensor 5, coupled with the wavefront discretization of the microlens array 51 and the high-resolution acquisition of the camera imaging chip 52, full-field Seidel aberration measurement with no high-frequency evaluation blind zone and low error accumulation is achieved. The entire implementation process does not require complex high-resolution image registration algorithms and dual-dimensional aberration coefficient matrix calculations. Through clear structural assembly relationships, standardized calibration steps, and simple aberration calculation formulas, it quickly outputs quantitative results of primary spherical aberration, coma, astigmatism, field curvature, and distortion. It effectively solves the shortcomings of traditional ISO standard-derived technologies, interferometers, and conventional wavefront sensors in Seidel aberration reconstruction, significantly improving the performance evaluation efficiency and quality control accuracy of optical components and imaging systems. It is suitable for aberration detection scenarios in various imaging systems with large field of view and high throughput.

[0114] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A Seidel aberration sensor for measurement in an optical imaging system, characterized in that, It includes an illumination system (1), a custom dot matrix target (2), an optical system to be measured (3), a collimating optical system (4), and a Seidel aberration sensor (5); The optical system to be measured (3) is provided with an aperture stop (31), and the Seidel aberration sensor (5) includes a microlens array (51) and a camera imaging chip (52). The customized dot matrix target (2) is located on the target plane of the optical system to be measured (3); The front focal plane of the collimating optical system (4) is located on the target image plane (21) of the customized dot matrix target (2) in the optical system to be measured (3). The plane of the microlens array (51) is located on the conjugate plane of the aperture stop (31) of the optical system to be measured (3) and the collimating optical system (4); The camera imaging chip (52) is located on the back focal plane of the microlens array (51); By using the calibration results of the customized dot matrix target (2) and the Seidel aberration sensor (5), and combining the centroid offset of the sensing image, the wavefront distribution at all points in the full field of view is calculated, thereby realizing the measurement of all Seidel aberrations, including primary spherical aberration, coma, astigmatism, field curvature, and distortion.

2. The Seidel aberration sensor according to claim 1, characterized in that, The customized dot matrix target (2) is made of metal or glass sheet and forms a hole array structure through laser, etching or electroplating processes; The calibration process of the customized dot matrix target (2) includes: taking magnified images of the customized dot matrix target (2) using a commercial microscope with a low distortion objective lens, and calculating the absolute position coordinates of the centroid of each light point on the dot matrix target (2) in combination with the magnification of the commercial microscope.

3. The Seidel aberration sensor according to claim 1, characterized in that, It also includes a Seidel aberration sensor calibration system, which consists of a multimode fiber optic patch cord (11), an LED light source (12), and a collimating lens (6); The light-emitting end face of the multimode fiber optic patch cord (11) is located at the front focal face of the collimating lens (6); The parallelism of the collimated beam of the calibration system is ensured by real-time feedback adjustment using commercial wavefront sensors or interferometers, and the width of the collimated beam covers the working surface of the Seidel aberration sensor (5).

4. The Seidel aberration sensor according to claim 1, characterized in that, The steps for measuring Seidel aberration include: S1: Obtain the sensor image of the custom dot matrix target (2) captured by the Seidel aberration sensor (5), and determine the center position and beam width of the incident beam based on the overall energy distribution of the image; S2: Segment the sub-images corresponding to each microlens (51) and calculate the centroid position of the lattice light spot of the complete sub-image within the beam range; S3: Align the calibration results of the Seidel aberration sensor (5) with the actual microlens (51), align the calibration results of the customized dot matrix target (2) with all target sub-images, and calculate the offset between the center spot of each group of dot matrix targets (2) in each microlens (51) and the centroid of the actual spot. S4: Based on the offset, reconstruct the wavefront distribution covering multiple points in the global field of view, represent the wavefront distribution using standard Zernike polynomials, decompose the Zernike coefficients with the distribution of field of view coordinates using polynomials, and substitute the decomposed coefficients into the Seidel aberration calculation formula to obtain all Seidel aberrations.

5. The Seidel aberration sensor according to claim 4, characterized in that, In step S4, each wavefront group is reconstructed independently. The centroid of each group of light spots is based on: The Moment-based space-variant Shack–Hartmann wavefront reconstruction method enables wavefront inversion.

6. The Seidel aberration sensor according to claim 1, characterized in that, In step S4, the wavefront distribution covering multiple points in the global field of view is expanded using standard Zernike polynomials.

7. The Seidel aberration sensor according to claim 1, characterized in that, In step S4, the Zernike coefficients are multinomially decomposed according to the distribution of the field of view.

8. The Seidel aberration sensor according to claim 1, characterized in that, In step S4, the Seidel aberration calculation formula is as follows: Spherical aberration: Calculated based on the 0th-order coefficients of polynomial decomposition using the coefficient distribution of the 11th term of the standard Zernike polynomial; Coma: Calculated based on the first-order coefficient combination of polynomial decomposition of the coefficient distribution of the 7th and 8th terms of the standard Zernike polynomial; Image-based calculation: Calculation of second-order coefficient combinations of polynomial decomposition based on the coefficient distribution of the 5th and 6th terms of the standard Zernike polynomial; Field curves: Calculation of second-order coefficient combinations of polynomial decomposition based on the coefficient distribution of the fourth term of the standard Zernike polynomial; Distortion: Calculated by combining the coefficients of the third order of polynomial decomposition based on the coefficient distribution of the second and third terms of the standard Zernike polynomial.

9. The Seidel aberration sensor according to claim 1, characterized in that, Suitable for Seidel aberration measurement in large field-of-view, high-throughput imaging systems, it avoids evaluation blind spots outside the Nyquist limit of the high-frequency modulation transfer function.

10. The Seidel aberration sensor according to claim 2, characterized in that, The aperture array specifications of the customized dot matrix target (2) can be adjusted according to the parameters of the optical system (3) to be measured and the Seidel aberration sensor (5). The aperture spacing ranges from 0.01 to 50 mm, and the aperture diameter ranges from 0.001 to 10 mm.

Images