Large aperture segmented telescope discretization confocal testing and adjustment method

Abstract

The present application relates to the technical field of confocal adjustment, and particularly relates to a large-aperture segmented telescope discretization confocal testing and adjustment method, which comprises the following steps: S1: placing a microlens array on the focal plane of the segmented telescope to rearrange the spatial frequency of the focal point of the segmented telescope; S2: performing differential operation on the light intensity of each light spot and the light intensity of the central sub-aperture to obtain the distance from each light spot to the central sub-aperture; S3: performing testing in each direction by using an eight-neighborhood algorithm according to the distance from each light spot to the central sub-aperture to determine the adjustment step and direction of the segmented telescope; and S4: adjusting the spliced sub-mirror of the segmented telescope according to the adjustment step and direction to maximize the energy of the central sub-aperture. The microlens array is used to rearrange the spatial frequency of the focal point, and higher-precision confocal testing and adjustment are finally achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of confocal adjustment, in particular to a large-aperture segmented telescope discrete confocal testing and adjustment method. BACKGROUND

[0002] For a large-aperture segmented telescope, confocal error correction is a basic prerequisite for improving energy concentration and ultimately achieving target detection. The traditional light point tracking method is low in efficiency, and the light point extraction error will seriously limit the confocal accuracy. SUMMARY

[0003] In view of the above problems, the present application provides a large-aperture segmented telescope discrete confocal testing and adjustment method, which uses a microlens array to rearrange the spatial frequency of the focal point, and finally realizes higher precision confocal testing and adjustment.

[0004] The large-aperture segmented telescope discrete confocal testing and adjustment method provided by the present application comprises:

[0005] S1: placing a microlens array on the focal plane of the segmented telescope to rearrange the spatial frequency of the focal point of the segmented telescope;

[0006] S2: placing a converging lens between the microlens array and the CCD detector to converge the light intensity of each light point, and adjusting the segmented primary mirror to make the converged light intensity reach more than 50% of the saturation light intensity of the CCD detector;

[0007] S3: removing the converging lens and differentiating the light intensity of each light point and the light intensity of the central sub-aperture to obtain the distance of each light point to the central sub-aperture;

[0008] S4: according to the distance of each light point to the central sub-aperture, using an eight-neighborhood algorithm to test in each direction to determine the adjustment step and direction of each sub-mirror of the segmented primary mirror;

[0009] S5: adjusting the segmented primary mirror according to the adjustment step and direction of each sub-mirror to maximize the energy of the central sub-aperture.

[0010] Preferably, a filter is arranged in the incident direction of the microlens array to reduce the spectral width and obtain interference fringes.

[0011] Preferably, the intensity I of the interference fringes is:

[0012] Where k is the wave number, θ is the angular spectrum, D is the beam aperture, B is the interval distance of the light beam, and δ is the optical path difference.

[0013] Preferably, in the adjustment process of step S5, firstly, the two adjacent sub-mirrors are adjusted to be confocal by using a mask, then the mask is removed, and finally all the sub-mirrors are adjusted to be confocal.

[0014] Compared with the prior art, the present application can achieve the following technical effects:

[0015] 1. Due to the fixing effect of the lens array, the traditional position intensity information is converted into only intensity information.

[0016] 2. The intensity of the light spot directly determines its position from the actual central sub-aperture, so that the distance from the actual light intensity center can be directly obtained by differential operation on the light spot intensity, and fast and accurate correction can be realized.

[0017] 3. By discretization and fixing, the traditional phase electric deviation test is converted into a simple light intensity test, and the test and adjustment difficulty is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a perspective structural view of the principle of the large-aperture segmented telescope discretization confocal test and adjustment method according to the embodiment of the present application;

[0019] Figure 2 is a planar structural view of the principle of the large-aperture segmented telescope discretization confocal test and adjustment method according to the embodiment of the present application.

[0020] Reference signs: spliced primary mirror 1, secondary mirror 2, CCD detector 3, sub-mirror 4, microlens array 5, converging lens 6. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. In the following description, the same modules are denoted by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0022] In order to make the objectives, technical solutions and advantages of the present application more clear, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and do not constitute a limitation on the present application.

[0023] Figure 1 and Figure 2 respectively show the perspective structure and the planar structure of the principle of the large-aperture segmented telescope discretization confocal test and adjustment method according to the embodiment of the present application.

[0024] As Figure 1 and Figure 2As shown, the large-aperture segmented telescope includes a splicing primary mirror 1, a secondary mirror 2, and a CCD detector 3. There may be other optical elements between the secondary mirror 2 and the CCD detector 3, which will not be described in detail in this invention. The splicing primary mirror 1 is composed of multiple sub-mirrors 4 spliced ​​together. Confocalization is achieved by focusing the pointing of multiple sub-mirrors 4 on a single point.

[0025] The confocal testing and adjustment method provided by this invention involves placing a microlens array 5 on the focal plane of a large-aperture segmented telescope, rearranging the spatial frequency of its focal point, and converting the traditional position intensity information into intensity-only measurement information.

[0026] Since confocal lenses have the characteristic of concentrated energy, the idea of ​​this invention to achieve confocal lensing is to disregard the shape of the light spot and only consider the energy of the light spot. By adjusting each sub-mirror 4, the energy of the central sub-aperture of the microlens array 5 is adjusted. When the energy of the central sub-aperture of the microlens array 5 reaches its maximum, the confocal adjustment of each sub-mirror 4 is completed.

[0027] Before adjusting the energy of the central sub-aperture of the microlens array 5, a converging lens 6 is placed between the microlens array 5 and the CCD detector 3 to converge the light intensity of each light point. By adjusting each sub-mirror 4, the converged light intensity reaches more than 50% of the saturation light intensity of the CCD detector 3, thus achieving coarse adjustment of the splicing master mirror 1. Then, the converging lens 6 is removed, the adjustment step size and direction of each sub-mirror 4 are calculated, and each sub-mirror 4 is adjusted to achieve fine adjustment of the splicing master mirror 1, maximizing the energy of the central sub-aperture.

[0028] The purpose of coarsely adjusting the splicing primary mirror 1 is to avoid using a large dynamic range CCD detector 3 and reduce costs.

[0029] The method for discretized confocal testing and adjustment of a large-aperture segmented telescope provided in this invention specifically includes the following steps:

[0030] S1: Place a microlens array on the focal plane of the segmented telescope to rearrange the spatial frequencies of the focal point of the segmented telescope.

[0031] The light from each sub-mirror will form different light spots after passing through the microlens array.

[0032] S2: A converging lens is placed between the microlens array and the CCD detector to converge the light intensity of each light point. By adjusting the splicing main mirror, the converged light intensity reaches more than 50% of the saturation light intensity of the CCD detector.

[0033] S3: Remove the converging lens, perform a difference calculation on the light intensity of each light spot and the light intensity of the central sub-aperture, and obtain the distance from each light spot to the central sub-aperture.

[0034] S4: Based on the distance of each light spot to the central sub-aperture, the eight-neighborhood algorithm is used to test in various directions to determine the adjustment step size and direction of each sub-mirror of the stitching master mirror.

[0035] S5: Adjust the splicing master mirror according to the adjustment step size and direction of each sub-mirror to maximize the energy of the central sub-aperture.

[0036] In the adjustment process of step S5, firstly, the two adjacent stitching sub-mirrors are adjusted to be confocal using a mask, then the mask is removed, and finally all the stitching sub-mirrors are adjusted to be confocal.

[0037] To improve positioning accuracy, a filter is placed along the incident direction of the microlens array to reduce the spectral width, transforming the broadband light incident on the CCD detector into narrowband light. Interference occurs between these narrowband lights, producing interference fringes. The intensity I of the interference fringes is:

[0038]

[0039] Where k is the wavenumber, θ is the angular spectrum, D is the beam aperture, B is the beam spacing, and δ is the optical path difference.

[0040] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0041] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for discretized confocal testing and adjustment of a large-aperture segmented telescope, characterized in that, include: S1: Place a microlens array on the focal plane of the segmented telescope to rearrange the spatial frequencies of the focal point of the segmented telescope. S2: A converging lens is placed between the microlens array and the CCD detector to converge the light intensity of each light point. The converged light intensity is adjusted by the splicing main mirror to reach more than 50% of the saturation light intensity of the CCD detector. S3: Remove the converging lens, perform a difference calculation on the light intensity of each light spot and the light intensity of the central sub-aperture, and obtain the distance from each light spot to the central sub-aperture. S4: Based on the distance from each light spot to the central sub-aperture, the eight-neighborhood algorithm is used to test in various directions to determine the adjustment step size and direction of each sub-mirror of the stitching master mirror. S5: Adjust the splicing master mirror according to the adjustment step size and direction of each sub-mirror to maximize the energy of the central sub-aperture.

2. The method for discrete confocal testing and adjustment of a large-aperture segmented telescope as described in claim 1, characterized in that, A filter is placed in the incident direction of the microlens array to reduce the spectral width and obtain interference fringes.

3. The method for discrete confocal testing and adjustment of a large-aperture segmented telescope as described in claim 2, characterized in that, The intensity I of the interference fringes is: Where k is the wavenumber, θ is the angular spectrum, D is the beam aperture, B is the beam spacing, and δ is the optical path difference.

4. The method for discretized confocal testing and adjustment of a large-aperture segmented telescope as described in claim 1, characterized in that, In the adjustment process of step S5, firstly, a mask is used to adjust two adjacent sub-mirrors to be confocal, then the mask is removed, and finally all sub-mirrors are adjusted to be confocal.

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