General-purpose compensator design method and device used in conjunction with sub-aperture stitching

Abstract

The application discloses a general partial compensator design method and device used in conjunction with a sub-aperture stitching technique, which has simple structure, high universality, and can significantly improve the efficiency of the sub-aperture stitching technique in detecting a large-aperture aspheric surface, and reduce the hardware requirements and cost required by the sub-aperture stitching technique in detecting the large-aperture aspheric surface. The method comprises the following steps: (1) acquiring system parameters of an aspheric surface measurement light path; (2) setting initial structure parameters of a partial compensator, wherein the partial compensator is composed of a double cemented lens; (3) taking a center sub-aperture of the aspheric surface as a measured mirror to optimize the structure of the partial compensator, and obtaining a partial compensator L0; (4) taking n circle sub-apertures outside the center aperture of the aspheric surface as measured mirrors to optimize the L0 respectively, and correspondingly obtaining partial compensators; (5) evaluating the compensation effect of the partial compensators, and selecting a partial compensator Lb with the best effect; and (6) taking the Lb as initial structure, and optimizing the Lb for a measured aspheric surface full aperture to obtain a final partial compensator Le.

Description

Technical Field

[0001] The present invention relates to the technical field of photoelectric detection, and in particular to a method for designing a universal partial compensator used in conjunction with sub-aperture stitching technology, and also to a universal partial compensator design device used in conjunction with sub-aperture stitching technology, which is mainly used to establish a set of universal partial compensator design models. Background Art

[0002] Optical systems containing aspheric surfaces have been increasingly widely used in modern optical systems due to their advantages of high imaging quality and small system size. With the rapid development of fields such as astronomical optics and applied optics, in order to achieve higher resolution of optical systems, the aperture of optical systems has become larger and larger, and higher requirements have been placed on the optical processing and manufacturing technology and optical detection technology of large-aperture surfaces. Among them, high-precision optical detection of large-aperture aspheric surfaces plays an important role in providing feedback and guidance for the design, processing, and assembly of large-aperture aspheric optical systems, and has important research significance. The commonly used aspheric optical detection method is interferometry, but for large-aperture aspheric surfaces, the aperture of the interferometer and the auxiliary optical system are not sufficient to cover the full aperture of the measured surface. Therefore, sub-aperture splicing interferometry is often used.

[0003] Subaperture stitching interferometry divides the component under test into multiple small-aperture subapertures, performs interferometric detection on each subaperture separately, and then uses the corresponding subaperture stitching algorithm to stitch the detection data of each subaperture to obtain the full-aperture surface shape information of the component under test. Subaperture stitching is simple, convenient, and highly accurate when detecting relatively small-aperture aspheric surfaces. However, for the detection of large-aperture aspheric surfaces, the subaperture diameter cannot be too large due to the constraints of the interferometer diameter and stitching accuracy. Using stitching detection alone will result in a large number of subapertures, increasing the detection time and the difficulty of data processing. More importantly, it aggravates the accumulation of errors, which limits the accuracy of stitching detection. Therefore, it is necessary to use subaperture stitching in conjunction with other methods to improve its detection effect on large-aperture aspheric surfaces.

[0004] The partial compensation method uses a lens or lens group as a compensator to compensate the plane wave or spherical wave emitted by the interferometer, converting it into a wavefront that is more closely matched with the aspheric surface being measured. The wavefront is reflected by the measured mirror and returns to the interferometer through the partial compensator again. The measurement light returning to the interferometer has a certain deviation from the plane wave or spherical wave, which is called the residual wavefront. However, the interference pattern is distinguishable, and the wavefront can be effectively restored, making the aspheric surface that could not be directly measured using an interferometer measurable. Summary of the Invention

[0005] In order to overcome the defects of the prior art, the technical problem to be solved by the present invention is to provide a universal partial compensator design method for use with sub-aperture stitching, which has the advantages of simple structure and strong versatility, significantly improves the efficiency of sub-aperture stitching in detecting large-aperture aspheric surfaces, and reduces the hardware requirements and costs required for sub-aperture stitching in detecting large-aperture aspheric surfaces.

[0006] The technical solution of the present invention is: a general partial compensator design method used in conjunction with sub-aperture stitching technology, which includes the following steps:

[0007] (1) Obtaining the system parameters of the aspheric surface measurement optical path;

[0008] (2) Setting the initial structural parameters of the partial compensator, which is composed of a doublet lens;

[0009] (3) The structure of the partial compensator is optimized by taking the aspheric central sub-aperture as the measured mirror to obtain the partial compensator L0;

[0010] (4) Taking the n sub-apertures outside the central aperture of the aspheric surface as the measured mirror L0, the partial compensators L1, L2, ..., Ln are obtained accordingly;

[0011] (5) Evaluate the compensation effects of the partial compensators L0, L1, ..., Ln, and select the partial compensator Lb with the best compensation effect;

[0012] (6) Taking the partial compensator Lb as the initial structure, the partial compensator Lb is optimized for the full aperture of the aspheric surface to obtain the final partial compensator Le;

[0013] The step (3) comprises the following sub-steps:

[0014] (3.1) Select optimization variables: Set the three curvature radii of the doublet lens, lens thickness, glass material, and the distance between the lens and the aspheric surface to be measured as optimization variables.

[0015] (3.2) Set the optimization target: Take wavefront as the optimization target, set the optimization target of Default Merit Function under the Tools submenu of MeritFunction menu to wavefront, and set its optimization type to RMS;

[0016] (3.3) Setting optimization operands: controlling the thickness of each lens of the doublet lens within the range of 10-30 mm through the minimum glass center thickness operand MNCG, the maximum glass center thickness operand MXCG, the minimum glass edge thickness operand MNEG, and the maximum glass edge thickness operand MXEG; controlling the distance from the doublet lens to the measured surface within the range of 1000-4000 mm through the minimum air center thickness operand MNCG, the maximum air center thickness operand MXCG, the minimum air edge thickness operand MNEG, and the maximum air edge thickness operand MXEG; inserting the operand REAY as ray tracing, setting Py=1 at the measured aspheric surface, and optimizing the target to D0 / 2, so that the upper edge light after passing through the positive lens reaches the upper edge of the measured convex aspheric surface, and then inserting the same operand REAY, setting Py=-1, and optimizing the target to -D0 / 2, so that the lower edge light after passing through the lens reaches the lower edge of the measured aspheric surface, thereby controlling the light of the partial compensation detection system to detect the full aperture of the measured aspheric surface;

[0017] (3.4) Perform optimization: Optimize the partial compensation detection system.

[0018] The present invention designs a partial compensator for the central sub-aperture of the aspheric surface to be measured, and optimizes it in combination with sub-apertures at different positions. A single partial compensator can be used to complete the compensation of all sub-aperture measurement optical paths of the large-aperture measured surface. This has the advantage of strong versatility and significantly improves the efficiency of sub-aperture stitching in detecting large-aperture aspheric surfaces. The partial compensator of the present invention is composed of only a double-cemented lens, has a simple structure, and significantly reduces the hardware requirements and costs required for sub-aperture stitching in detecting large-aperture aspheric surfaces.

[0019] A general partial compensator design device for use with subaperture stitching is also provided, comprising:

[0020] A system parameter acquisition module configured to obtain various system parameters of the aspheric surface measurement optical path;

[0021] an initial structural parameter setting module configured to set initial structural parameters of a partial compensator, the partial compensator being composed of a doublet lens;

[0022] A central sub-aperture optimization module is configured to optimize the structure of the partial compensator using the aspheric central sub-aperture as the measured mirror to obtain the partial compensator L0;

[0023] The non-central sub-aperture optimization module is configured to optimize the n-circle sub-aperture outside the central aperture of the aspheric surface as the measured mirror L0, and obtain the partial compensator L1 accordingly.

[0024] L2…Ln;

[0025] a compensator evaluation module configured to evaluate the compensation effect of the partial compensators L0, L1,..., Ln, and select the partial compensator Lb with the best compensation effect;

[0026] a full-aperture optimization module configured to take the partial compensator Lb as an initial structure, and optimize the partial compensator Lb for the full aperture of the measured aspheric surface to obtain a final partial compensator Le;

[0027] The central sub-aperture optimization module performs the following steps:

[0028] (3.1) Select optimization variables: set the three curvature radii of the double-cemented lens, the lens thickness, the glass material, and the distance between the lens and the measured aspheric surface as the optimization variables.

[0029] (3.2) Set the optimization target: set the optimization target of the MeritFunction menu under the Tools submenu as wavefront, and set the optimization type as the root mean square value RMS;

[0030] (3.3) Set the optimization operation number: control the thickness of each lens of the double-cemented lens within the range of 10-30 mm through the minimum glass center thickness operation number MNCG, the maximum glass center thickness operation number MXCG, the minimum glass edge thickness operation number MNEG, and the maximum glass edge thickness operation number MXEG; control the distance between the double-cemented lens and the measured surface within the range of 1000-4000 mm through the minimum air center thickness operation number MNCG, the maximum air center thickness operation number MXCG, the minimum air edge thickness operation number MNEG, and the maximum air edge thickness operation number MXEG; insert the operation number REAY as ray tracing, set Py=1 at the measured aspheric surface, and set the optimization target as D0 / 2, so that the upper edge ray after passing through the positive lens reaches the upper edge of the measured convex aspheric surface; insert the same operation number REAY again, set Py=-1, and set the optimization target as -D0 / 2, so that the lower edge ray after passing through the lens reaches the lower edge of the measured aspheric surface, thereby controlling the ray of the partial compensation detection system to detect the full aperture of the measured aspheric surface;

[0031] (3.4) Perform optimization: optimize the partial compensation detection system. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a flowchart of a general partial compensator design method used in the matching sub-aperture stitching technique according to the present application.

[0033] Figure 2 is a layout diagram of an aspheric mirror sub-aperture.

[0034] Figure 3 is the layout diagram of compensator L0.

[0035] Figure 4 is the residual wavefront diagram of the system image plane.

[0036] Figure 5 It is a layout diagram of the compensator detecting different areas of the measured surface.

[0037] Figure 6 It is the residual wavefront image of the compensator detecting different areas of the measured surface. DETAILED DESCRIPTION

[0038] like Figure 1 As shown, the general partial compensator design method used in conjunction with sub-aperture stitching includes the following steps:

[0039] (1) Obtaining the system parameters of the aspheric surface measurement optical path;

[0040] (2) Setting the initial structural parameters of the partial compensator, which is composed of a doublet lens;

[0041] (3) The structure of the partial compensator is optimized by taking the aspheric central sub-aperture as the measured mirror to obtain the partial compensator L0;

[0042] (4) Taking the n sub-apertures outside the central aperture of the aspheric surface as the measured mirror L0, the partial compensators L1, L2, ..., Ln are obtained accordingly;

[0043] (5) Evaluate the compensation effects of the partial compensators L0, L1, ..., Ln, and select the partial compensator Lb with the best compensation effect;

[0044] (6) Take the partial compensator Lb as the initial structure, and adjust the partial compensator Lb for the full aperture of the aspheric surface to be measured.

[0045] The compensator Lb is optimized to obtain the final partial compensator Le;

[0046] The step (3) comprises the following sub-steps:

[0047] (3.1) Select optimization variables: Set the three curvature radii of the doublet lens, lens thickness, glass material, and the distance between the lens and the aspheric surface to be measured as optimization variables.

[0048] (3.2) Set the optimization target: Take wavefront as the optimization target, set the optimization target of Default Merit Function under the Tools submenu of the Merit Function menu to wavefront, and set its optimization type to RMS;

[0049] (3.3) Setting optimization operands: controlling the thickness of each lens of the doublet lens within the range of 10-30 mm through the minimum glass center thickness operand MNCG, the maximum glass center thickness operand MXCG, the minimum glass edge thickness operand MNEG, and the maximum glass edge thickness operand MXEG; controlling the distance from the doublet lens to the measured surface within the range of 1000-4000 mm through the minimum air center thickness operand MNCG, the maximum air center thickness operand MXCG, the minimum air edge thickness operand MNEG, and the maximum air edge thickness operand MXEG; inserting the operand REAY as ray tracing, setting Py=1 at the measured aspheric surface, and optimizing the target to D0 / 2, so that the upper edge light after passing through the positive lens reaches the upper edge of the measured convex aspheric surface, and then inserting the same operand REAY, setting Py=-1, and optimizing the target to -D0 / 2, so that the lower edge light after passing through the lens reaches the lower edge of the measured aspheric surface, thereby controlling the light of the partial compensation detection system to detect the full aperture of the measured aspheric surface;

[0050] (3.4) Perform optimization: Optimize the partial compensation detection system.

[0051] The present invention designs a partial compensator for the central sub-aperture of the aspheric surface to be measured, and optimizes it in combination with sub-apertures at different positions. A single partial compensator can be used to complete the compensation of all sub-aperture measurement optical paths of the large-aperture measured surface. This has the advantage of strong versatility and significantly improves the efficiency of sub-aperture stitching in detecting large-aperture aspheric surfaces. The partial compensator of the present invention is composed of only a double-cemented lens, has a simple structure, and significantly reduces the hardware requirements and costs required for sub-aperture stitching in detecting large-aperture aspheric surfaces.

[0052] Preferably, in step (1), the system parameters include: the vertex curvature radius, aperture, quadratic surface coefficient of the aspheric surface to be measured, the aperture and arrangement of the sub-apertures, the entrance pupil diameter of the measuring optical path and the wavelength of the incident light.

[0053] Preferably, in step (2), some of the initial structural parameters of the compensator include: lens thickness, material, curvature radius of each mirror surface, and the distance between the lens and the measured mirror.

[0054] Preferably, in step (2), for a concave aspheric surface with a small asphericity, a doublet lens with a small spherical aberration is used to compensate; the aperture of the doublet lens is larger than the system entrance pupil diameter, the initial curvature radius of the three surfaces is set to infinity, and initial values ​​are given for the glass thickness, glass material, and the distance between the compensator and the measured surface.

[0055] Preferably, in the step (4), the optimization process in the step (3) is repeated to optimize the first, second and third circle of sub-apertures respectively, and the partial compensators L1, L2 and L3 are obtained correspondingly, by measuring different positions of the sub-apertures through the measured mirror decentration and tilt angle, and changing the optimization target to translation, tilt, defocus and astigmatism errors when measuring the non-central sub-aperture region of the measured mirror.

[0056] Preferably, in the step (5), the average value of the residual wavefront after the compensation of the compensator for the central sub-aperture and the other n circle of sub-apertures is taken as the evaluation index.

[0057] Preferably, in the step (6), the multiple structure is set in the Zemax software, the central sub-aperture and the other three circle of sub-apertures are taken as the measured objects, the partial compensator L3 is taken as the initial structure, the optimization process in the step (3) is repeated to obtain the final partial compensator Le.

[0058] Those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment methods can be completed by programs instructing related hardware, and the programs can be stored in a computer readable storage medium, which includes the steps of the above-mentioned embodiment methods when executed, and the storage medium can be ROM / RAM, a magnetic disc, an optical disc, a memory card, etc. Therefore, corresponding to the method of the present application, the present application also simultaneously includes a general partial compensator design device used in conjunction with the sub-aperture stitching technique, which is usually represented in the form of functional modules corresponding to the steps of the method. The device includes:

[0059] a system parameter acquisition module configured to acquire the system parameters of the aspheric surface measurement optical path;

[0060] an initial structure parameter setting module configured to set the initial structure parameters of the partial compensator, which is composed of a double cemented lens;

[0061] a central sub-aperture optimization module configured to optimize the structure of the partial compensator by taking the central sub-aperture of the aspheric surface as the measured mirror, and obtain the partial compensator L0;

[0062] a non-central sub-aperture optimization module configured to optimize the L0 by taking the n circle of sub-apertures outside the central aperture of the aspheric surface as the measured mirror, and obtain the partial compensators L1,

[0063] L2……Ln;

[0064] a compensator evaluation module configured to evaluate the compensation effect of the partial compensators L0, L1……Ln, and select the partial compensator Lb with the best compensation effect;

[0065] A full-aperture optimization module is configured to use the partial compensator Lb as an initial structure and optimize the partial compensator Lb for the full aperture of the aspheric surface being measured to obtain the final partial compensator Le;

[0066] The central subaperture optimization module performs the following sub-steps:

[0067] (3.1) Select optimization variables: Set the three curvature radii of the doublet lens, lens thickness, glass material, and the distance between the lens and the aspheric surface to be measured as optimization variables.

[0068] (3.2) Set the optimization target: Take wavefront as the optimization target, set the optimization target of Default Merit Function under the Tools submenu of MeritFunction menu to wavefront, and set its optimization type to RMS;

[0069] (3.3) Setting optimization operands: controlling the thickness of each lens of the doublet lens within the range of 10-30 mm through the minimum glass center thickness operand MNCG, the maximum glass center thickness operand MXCG, the minimum glass edge thickness operand MNEG, and the maximum glass edge thickness operand MXEG; controlling the distance from the doublet lens to the measured surface within the range of 1000-4000 mm through the minimum air center thickness operand MNCG, the maximum air center thickness operand MXCG, the minimum air edge thickness operand MNEG, and the maximum air edge thickness operand MXEG; inserting the operand REAY as ray tracing, setting Py=1 at the measured aspheric surface, and optimizing the target to D0 / 2, so that the upper edge light after passing through the positive lens reaches the upper edge of the measured convex aspheric surface, and then inserting the same operand REAY, setting Py=-1, and optimizing the target to -D0 / 2, so that the lower edge light after passing through the lens reaches the lower edge of the measured aspheric surface, thereby controlling the light of the partial compensation detection system to detect the full aperture of the measured aspheric surface;

[0070] (3.4) Perform optimization: Optimize the partial compensation detection system.

[0071] Preferably, in the system parameter acquisition module, the system parameters include: the vertex curvature radius, aperture, quadratic surface coefficient of the measured aspheric surface, the aperture and arrangement of the sub-apertures, the entrance pupil diameter of the measurement light path and the wavelength of the incident light.

[0072] Preferably, in the initial structural parameter setting module, some of the initial structural parameters of the compensator include: lens thickness, material, curvature radius of each mirror surface, and the distance between the lens and the measured mirror.

[0073] The following describes in detail a specific embodiment of the present invention. A general partial compensator design method for subaperture stitching for detecting large-aperture concave aspheric surfaces is implemented as follows:

[0074] The general partial compensator design method that can be used with subaperture stitching is as follows: Figure 1 As shown, the specific implementation steps are:

[0075] Step 1: Obtain the system parameters of the aspheric surface measurement optical path.

[0076] The aperture of the target aspheric mirror is 455mm, the vertex curvature radius is 2000mm, the aspheric coefficient is -1, the entrance pupil diameter of the measurement light path is 64mm, and the incident light wavelength is 633nm. The subaperture layout of the aspheric mirror is as follows: Figure 2 As shown, the diameter of all subapertures is 99 mm. In addition to the central subaperture, there are 3 circles of apertures. The first circle has 6 subapertures, the second circle has 12 subapertures, and the third circle has 18 subapertures.

[0077] In ZEMAX software, the entrance pupil diameter of the partial compensation system was set to 64 mm and the wavelength was set to 633 nm.

[0078] Step 2: Set some initial compensator structural parameters.

[0079] For concave aspheric surfaces with minimal asphericity, a doublet lens with minimal spherical aberration can be used for compensation. The doublet's aperture should be slightly larger than the system's entrance pupil diameter. The initial radius of curvature of the three surfaces can be set to infinity, and initial values ​​are given for the glass thickness, glass material, and distance between the compensator and the measured surface. Based on this, the initial structure of the doublet's compensator is determined and imported into ZEMAX optical design software.

[0080] Step 3: Optimize the structure of the partial compensator by taking the aspheric central sub-aperture as the measured mirror to obtain the partial compensator L0.

[0081] The optimization operations are as follows:

[0082] (1) Select optimization variables. Set the three curvature radii of the doublet lens, lens thickness, glass material, and the distance between the lens and the aspheric surface to be measured as optimization variables.

[0083] (2) Set the optimization target. Take wavefront as the optimization target. Set the optimization target of the Default Merit Function under the Tools submenu of the Merit Function menu to wavefront, and set its optimization type to RMS.

[0084] (3) Setting the optimization operands. The thickness of each lens of the doublet lens is controlled within the range of 10-30 mm by the minimum glass center thickness operand MNCG, the maximum glass center thickness operand MXCG, the minimum glass edge thickness operand MNEG, and the maximum glass edge thickness operand MXEG. The distance between the doublet lens and the measured surface is controlled within the range of 1000-4000 mm by the minimum air center thickness operand MNCG, the maximum air center thickness operand MXCG, the minimum air edge thickness operand MNEG, and the maximum air edge thickness operand MXEG. Insert the operand REAY as a ray tracer, set Py=1 at the measured aspheric surface, and optimize the target to D0 / 2, so that the upper edge light after passing through the positive lens reaches the upper edge of the measured convex aspheric surface. Then insert the same operand REAY, set Py=-1, and optimize the target to -D0 / 2, so that the lower edge light after passing through the lens reaches the lower edge of the measured aspheric surface, thereby controlling the light of the partial compensation detection system to detect the full aperture of the measured aspheric surface.

[0085] (4) Automatic optimization: Run the Optimization automatic optimization program to optimize the partial compensation detection system.

[0086] Figure 3 The figure shows the layout of the optimized partial compensator L0. In the compensation test optical path, after one concave aspheric reflection and two doublet lens compensations, the image is captured by a 2048×2048 pixel CCD. The residual wavefront on the system image plane is as follows: Figure 4 As shown in the figure, the RMS value of the residual wavefront is only 0.0004λ, and the peak-to-valley value is 0.0015λ, which shows that the partial compensator L0 has a good compensation capability for the central sub-aperture area of ​​the measured mirror.

[0087] Step 4: Optimize L0 by taking the three sub-apertures outside the central aperture of the aspheric surface as the measured mirror, and obtain partial compensators L1, L2, and L3 accordingly.

[0088] The sub-apertures at different positions can be measured by the eccentricity and pitch angle of the measured mirror, such as Figure 5 The following diagram shows the layout of the compensator for different areas of the measured surface. Since the double-cemented partial compensator is designed for the central subaperture, it performs best in the central area. When measuring non-central subaperture areas of the measured mirror, errors such as translation, tilt, defocus, and astigmatism are inevitably introduced. The compensation effect decreases with distance from the central subaperture. Change the optimization target to translation, tilt, defocus, and astigmatism errors, and repeat the optimization process in step three to optimize the first, second, and third subapertures, respectively. Partial compensators L1, L2, and L3 are obtained accordingly.

[0089] Step 5: Evaluate the compensation effects of the partial compensators L0, L1...Ln, and select the partial compensator Lb with the best compensation effect.

[0090] Selecting "wavefront map" under the "Analysis" tab in Zemax software reveals the residual wavefront of the system after compensating for the aspheric surface under test. The average residual wavefront of the compensator for the central subaperture and the other three subapertures is used as the evaluation metric. The average residual wavefront for partial compensator L0 is 2.10λ, 1.57λ for partial compensator L1, 1.52λ for partial compensator L2, and 1.29λ for partial compensator L3. Partial compensator L3 provides the best compensation.

[0091] Step 6: Take the partial compensator L3 as the initial structure, optimize the partial compensator L3 for the full aperture of the aspheric surface to obtain the final partial compensator Le.

[0092] Set up multiple structures in Zemax software, take the central sub-aperture and the other three circles of apertures as the measured objects, use the partial compensator L3 as the initial structure, repeat the optimization process in step 3, and obtain the final partial compensator Le.

[0093] The subapertures at four locations were tested using the partial compensator Le. Figure 6 In order to optimize the residual wavefront of the compensator to detect different areas of the measured surface, the RMS values ​​of the residual wavefront of the compensator detection center, first circle, second circle, and third circle apertures are 1.2822λ, 1.2490λ, 1.2025λ, and 1.5247λ, respectively.

[0094] The beneficial effects of the present invention are as follows:

[0095] 1. The present invention discloses a universal partial compensator design method for subaperture stitching. By designing a partial compensator for the central subaperture of the aspheric surface to be measured and optimizing it in combination with subapertures at different positions, a single partial compensator can complete the compensation of all subaperture measurement optical paths of a large-aperture measured surface. This method has the advantage of strong versatility and significantly improves the efficiency of subaperture stitching in detecting large-aperture aspheric surfaces.

[0096] 2. The present invention discloses a general partial compensator design method for sub-aperture stitching. The partial compensator is composed of only a doublet lens, which has a simple structure and significantly reduces the hardware requirements and costs required for sub-aperture stitching to detect large-aperture aspheric surfaces.

[0097] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A general partial compensator design method for use with subaperture stitching, characterized by: It includes the following steps: (1) Obtaining the system parameters of the aspheric surface measurement optical path; (2) Setting the initial structural parameters of the partial compensator, which is composed of a doublet lens; (3) The structure of the partial compensator is optimized by taking the aspheric central sub-aperture as the measured mirror to obtain the partial compensator L0; (4) Taking the n sub-apertures outside the central aperture of the aspheric surface as the measured mirror L0, the partial compensators L1, L2, ..., Ln are obtained accordingly; (5) Evaluate the compensation effects of the partial compensators L0, L1, ..., Ln, and select the partial compensator Lb with the best compensation effect; (6) Taking the partial compensator Lb as the initial structure, the partial compensator Lb is optimized for the full aperture of the aspheric surface to obtain the final partial compensator Le; The step (3) comprises the following sub-steps: (3.1) Select optimization variables: Set the three curvature radii of the doublet lens, lens thickness, glass material, and the distance between the lens and the aspheric surface to be measured as optimization variables; (3.2) Set the optimization target: Take wavefront as the optimization target, set the optimization target of Default Merit Function under the Tools submenu of MeritFunction menu to wavefront, and set its optimization type to RMS; (3.3) Setting optimization operands: controlling the thickness of each lens of the doublet lens within the range of 10-30 mm through the minimum glass center thickness operand MNCG, the maximum glass center thickness operand MXCG, the minimum glass edge thickness operand MNEG, and the maximum glass edge thickness operand MXEG; controlling the distance from the doublet lens to the measured surface within the range of 1000-4000 mm through the minimum air center thickness operand MNCG, the maximum air center thickness operand MXCG, the minimum air edge thickness operand MNEG, and the maximum air edge thickness operand MXEG; inserting the operand REAY as ray tracing, setting Py=1 at the measured aspheric surface, and optimizing the target to D0 / 2, so that the upper edge light after passing through the positive lens reaches the upper edge of the measured convex aspheric surface, and then inserting the same operand REAY, setting Py=-1, and optimizing the target to -D0 / 2, so that the lower edge light after passing through the lens reaches the lower edge of the measured aspheric surface, thereby controlling the light of the partial compensation detection system to detect the full aperture of the measured aspheric surface; (3.4) Perform optimization: Optimize the partial compensation detection system.

2. The universal partial compensator design method for use with subaperture stitching according to claim 1, characterized in that: In the step (1), the system parameters include: the vertex curvature radius, aperture, quadratic surface coefficient of the aspheric surface to be measured, the aperture and arrangement of the sub-apertures, the entrance pupil diameter of the measuring light path and the wavelength of the incident light.

3. The universal partial compensator design method for use with subaperture stitching according to claim 2, characterized in that: In the step (2), the initial structural parameters of some compensators include: lens thickness, material, curvature radius of each mirror surface, and the distance between the lens and the measured mirror.

4. The method for designing a universal partial compensator for use with subaperture stitching according to claim 3, characterized in that: In the step (2), for a concave aspheric surface with a small asphericity, a doublet lens with a small spherical aberration is used to compensate; the aperture of the doublet lens is larger than the system entrance pupil diameter, the initial curvature radius of the three surfaces is set to be infinite, and initial values ​​are given for the glass thickness, glass material, and the distance between the compensator and the measured surface.

5. The method for designing a universal partial compensator for use with subaperture stitching according to claim 4, characterized in that: In the step (4), the subapertures at different positions are measured by the eccentricity and pitch angle of the measured mirror. When measuring the non-central subaperture area of ​​the measured mirror, the optimization target is changed to translation, tilt, defocus and astigmatism errors. The optimization process in step (3) is repeated to optimize the subapertures of the first, second and third circles respectively, and the partial compensators L1, L2 and L3 are obtained accordingly.

6. The method for designing a universal partial compensator for use with subaperture stitching according to claim 5, characterized in that: In the step (5), the average value of the residual wavefront after the compensator compensates the central sub-aperture and the other n-circle apertures is used as an evaluation index.

7. The universal partial compensator design method for use with subaperture stitching according to claim 6, characterized in that: In step (6), multiple structures are set in Zemax software, and the central sub-aperture and the other three circles of apertures are taken as the objects to be measured. The partial compensator L3 is taken as the initial structure, and the optimization process in step (3) is repeated to obtain the final partial compensator Le.

8. A general partial compensator design device for use with subaperture stitching, characterized in that: It includes: A system parameter acquisition module configured to obtain various system parameters of the aspheric surface measurement optical path; an initial structural parameter setting module configured to set initial structural parameters of a partial compensator, the partial compensator being composed of a doublet lens; A central sub-aperture optimization module is configured to optimize the structure of the partial compensator using the aspheric central sub-aperture as the measured mirror to obtain the partial compensator L0; The non-central sub-aperture optimization module is configured to optimize the n-circle sub-aperture outside the central aperture of the aspheric surface as the measured mirror L0, and obtain the partial compensator L1 accordingly. L2…Ln; A compensator evaluation module is configured to evaluate the compensation effects of the partial compensators L0, L1...Ln and select the partial compensator Lb with the best compensation effect; A full-aperture optimization module is configured to use the partial compensator Lb as an initial structure and optimize the partial compensator Lb for the full aperture of the aspheric surface being measured to obtain the final partial compensator Le; The central subaperture optimization module performs the following sub-steps: (3.1) Select optimization variables: Set the three curvature radii of the doublet lens, lens thickness, glass material, and the distance between the lens and the aspheric surface to be measured as optimization variables; (3.2) Set the optimization target: Take wavefront as the optimization target, set the optimization target of Default Merit Function under the Tools submenu of MeritFunction menu to wavefront, and set its optimization type to RMS; (3.3) Setting optimization operands: controlling the thickness of each lens of the doublet lens within the range of 10-30 mm through the minimum glass center thickness operand MNCG, the maximum glass center thickness operand MXCG, the minimum glass edge thickness operand MNEG, and the maximum glass edge thickness operand MXEG; controlling the distance from the doublet lens to the measured surface within the range of 1000-4000 mm through the minimum air center thickness operand MNCG, the maximum air center thickness operand MXCG, the minimum air edge thickness operand MNEG, and the maximum air edge thickness operand MXEG; inserting the operand REAY as ray tracing, setting Py=1 at the measured aspheric surface, and optimizing the target to D0 / 2, so that the upper edge light after passing through the positive lens reaches the upper edge of the measured convex aspheric surface, and then inserting the same operand REAY, setting Py=-1, and optimizing the target to -D0 / 2, so that the lower edge light after passing through the lens reaches the lower edge of the measured aspheric surface, thereby controlling the light of the partial compensation detection system to detect the full aperture of the measured aspheric surface; (3.4) Perform optimization: Optimize the partial compensation detection system.

9. The universal partial compensator design device for use with subaperture stitching according to claim 8, characterized in that: In the system parameter acquisition module, the system parameters include: the vertex curvature radius, aperture, quadratic surface coefficient of the measured aspheric surface, the aperture and arrangement of the sub-apertures, the entrance pupil diameter of the measurement light path and the wavelength of the incident light.

10. The universal partial compensator design device for use with subaperture stitching according to claim 9, characterized in that: In the initial structural parameter setting module, some of the initial structural parameters of the compensator include: lens thickness, material, curvature radius of each mirror surface, and the distance between the lens and the measured mirror.

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