天文望远镜无偏消旋镜装调方案设计及验证  

Design and Verification of Depolarized Derotator Alignment Scheme in Astronomical Telescope

作　　者：周明尧 侯俊峰[1,2] 王东光 邓元勇[1,2] Zhou Mingyao;Hou Junfeng;Wang Dongguang;Deng Yuanyong(Key Laboratory of Solar Activity,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院国家天文台太阳活动重点实验室,北京100101 [2]中国科学院大学天文与空间科学学院,北京100049

出　　处：《中国激光》2020年第6期205-213,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(11427901,11773040,11403047,11427803);中国科学院空间科学战略性先导科技专项(XDA15010800,XDA15320102);中国科学院国家天文台所级公共技术服务中心项目(Y829011V01)。

摘　　要：地平式天文望远镜在跟踪观测过程中,因方位轴与地球自转轴不重合及库徳光路中的折轴反射镜在望远镜跟踪过程中相对转动,会引入物方及像方视场旋转。传统的消旋K镜可以消除视场旋转,但会带来较大的仪器偏振,不利于望远镜实现高精度偏振测量。无偏消旋镜由5块反射镜组成,通过优化设计可以保证在消除像旋的同时减小仪器偏振,但其不规则的结构设计使装调过程面临新的挑战。针对无偏消旋镜提出双光路自准直装调方案,基于MATLAB仿真分析了镜面误差及光轴偏差对装调结果的影响,并对无偏消旋镜进行实验室装调及偏振检测。结果表明:无偏消旋镜经装调后倾斜误差可控制在15 arcsec以内,其仪器偏振明显低于传统K镜。The misalignment between the azimuth axis of telescope and rotation axis of earth induces object-side field rotation,and the relative motion of folding mirrors in the Coude optical path induces image-side field rotation.The misalignment and rotation both occur during the process of the alt-azimuth telescope tracking observation.A K-mirror can compensate for the rotation but is inappropriate in high-precision polarimetry owing to its higher instrumental polarization.By optimizing the design,the depolarized derotator comprising five mirrors can reduce instrumental polarization while eliminating field rotation.However,its irregular structural design leads to a more complex alignment process.Herein,an auto-collimation dual optical path alignment scheme was designed for the depolarized derotator.The influence of mirror position error and optical axis deviation on the alignment process was analyzed using MATLAB simulation.The alignment and polarization detection for the depolarized derotator were conducted in the lab.Results indicated that the alignment error of the depolarized derotator was within 15 arcsec,and its instrumental polarization was significantly lower than that of the K-mirror.

关 键 词：测量 偏振测量 无偏消旋镜 装调方案 双光路 天文望远镜 

分 类 号：TB133[机械工程—光学工程]