菲涅尔透镜拼接失调误差分析与仿真

发布时间：2018-04-20 07:59

本文选题：拼接菲涅尔透镜 + 失调误差　；参考：《中国科学院大学(中国科学院光电技术研究所)》2017年硕士论文

【摘要】：薄膜状菲涅尔透镜因其质量轻、易于复制、面型公差较为宽松的优点,在未来超大口径天文望远镜方面有着广阔的应用前景。成像用菲涅尔透镜在目前的加工技术条件下要实现大口径,只能采用子镜拼接技术。子镜拼接过程中由于各方面因素造成的子镜间的失调将会对最终拼接而成的主镜的成像质量造成影响。本文针对拼接菲涅尔透镜失调误差的分析、检测和相关实验做了如下的工作:1.分别调研了国内外大型拼接天文望远镜的发展现状、各种主流的子镜拼接对准检测技术和菲涅尔透镜成像原理,结合研究背景和现状提出了本文的研究目的和意义。2.建立了两片式和多片式拼接菲涅尔透镜数值仿真模型,基于衍射光学理论,推导拼接镜在任意失调误差情况下的点扩散函数的解析表达式,以此分析各失调误差对拼接镜成像质量的影响。并根据斯特列尔准则,计算各失调误差单独存在时的误差容限,分析了误差容限和拼接镜F数之间的关系。3.结合了菲涅尔透镜成像特性与失调误差对其成像质量影响的分析结果,提出了一种基于拼接镜点扩散函数图像和光自准直测角原理的失调误差检测方案。对该方案的原理和具体步骤进行了详细的介绍,并在zemax软件中进行了仿真验证。该方法能够对拼接镜中带有的多种失调误差进行有效的检测,并且精度达到拼接镜理想成像的误差容限要求。4.根据本文所提失调误差检测方案设计搭建了相应实验平台,设计了两个实验。实验一设计了口径40mm,焦距400mm的两片式拼接菲涅尔透镜,采用PI六维调整台作为子镜误差校正控制系统,采用ESDI干涉仪作为平行光源以及光自准直测角系统。首先基于光自准直测角系统检测校正子镜绕X\Y轴旋转倾斜误差,然后通过CCD在拼接镜焦面获得点扩散函数图像。根据点扩散函数图像和子镜X\Y\Z轴平移误差建立的关系反算子镜失调误差并校正。该方案实现了子镜间的高精度对准,其检测精度为:AZ测量标准差σz为27.2 μ m,AX和△Y测量标准差σXY为0.26 μ m,θX和θY检测误差小于0.1 °满足各失调误差容限要求。实验二对经实验一校正完失调误差后的拼接镜进行干涉检测。根据菲涅尔透镜成像特性采用自准直干涉检测技术,使用4D动态干涉仪作为测量仪器,通过反复调整干涉仪和平面反射镜的位置,获得拼接镜的波前数据,其光学波前为0.26λ,基本符合瑞利判据,说明本文所提失调误差检测方案的可行性。
[Abstract]:Thin film Fresnel lens has a wide application prospect in the future because of its advantages of light weight, easy replication and loose surface tolerance. In order to realize large aperture Fresnel lens can only be spliced by sub-mirror. The misalignment between sub-mirrors caused by various factors in the process of sub-mirror stitching will affect the imaging quality of the final spliced primary mirror. In this paper, the following work has been done: 1: 1 for the analysis of misalignment error of Fresnel lens splicing, detection and related experiments. The development status of large spliced astronomical telescopes at home and abroad, various mainstream sub-mirror alignment detection techniques and Fresnel lens imaging principle are investigated respectively. The purpose and significance of this paper are put forward in combination with the research background and present situation. A numerical simulation model of Fresnel lens with two or more splices is established. Based on the theory of diffractive optics, the analytical expression of point diffusion function of splicing mirror under arbitrary misalignment error is derived. The influence of the misalignment error on the imaging quality of the splicing mirror is analyzed. According to the Stryer criterion, the error tolerance of each misalignment error is calculated, and the relationship between the error tolerance and the F number of splicing mirror is analyzed. Based on the analysis of the effect of Fresnel lens imaging characteristics and misalignment errors on the imaging quality, a scheme of misalignment error detection based on the splicing point diffusion function image and the principle of optical self-collimation angle measurement is proposed. The principle and concrete steps of the scheme are introduced in detail, and the simulation is carried out in zemax software. This method can effectively detect the misalignment errors in the splicing mirror, and the precision can reach the error tolerance requirement of the ideal image of the splicing mirror. According to the design of the misalignment error detection scheme proposed in this paper, a corresponding experimental platform is built, and two experiments are designed. In experiment 1, a two-slice Fresnel lens with 40mm aperture and focal length 400mm is designed. The Pi six-dimensional adjusting platform is used as the sub-mirror error correction control system, the ESDI interferometer is used as the parallel light source and the optical self-collimation angle measuring system is used. Firstly, based on the optical self-collimation angle measurement system, the correction sub-mirror rotates the tilt error around the X\ Y axis, and then the point diffusion function image is obtained by CCD in the focal plane of the spliced mirror. Based on the point diffusion function image and the translation error of the X\ Y\ Z axis of the sub-mirror, the misalignment error of the inverse operator mirror is established and corrected. In this scheme, the high precision alignment between sub-mirrors is realized. The detection accuracy is that the measurement standard deviation 蟽 _ z of: AZ is 27.2 渭 m, the standard deviation 蟽 _ XY of Y is 0.26 渭 m, and the detection errors of 胃 _ X and 胃 _ Y are less than 0.1 掳to meet the tolerance requirements of each misalignment error. Experiment 2 detects the interference of splicing mirror after correcting the misalignment error in experiment 1. According to the imaging characteristics of Fresnel lens, the self-collimation interferometry technique is used, and the 4D dynamic interferometer is used as the measuring instrument. The wavefront data of the spliced mirror are obtained by repeatedly adjusting the position of the interferometer and the plane reflector. The optical wavefront is 0.26 位, which basically accords with the Rayleigh criterion, which shows the feasibility of the proposed scheme of misalignment error detection.
【学位授予单位】：中国科学院大学(中国科学院光电技术研究所)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH751

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