8m中国巨型太阳望远镜偏振光学设计  

Polarization Optical Design of 8-meter Chinese Giant Solar Telescope

作　　者：付玉[1,2] 袁沭 金振宇[1] 刘忠[1,2] FU Yu;YUAN Shu;JIN Zhen-yu;LIU Zhong(Yunnan Astronomical Observatory,Chinese Academy of Sciences,Kunming 650011;University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]中国科学院云南天文台,昆明650011 [2]中国科学院大学,北京100049

出　　处：《天文学报》2023年第1期70-82,共13页Acta Astronomica Sinica

基　　金：国家自然科学基金项目(11773069、11773071)资助。

摘　　要：望远镜的仪器偏振是影响太阳磁场测量的重要因素,为了获得精确的太阳磁场信息,对大型太阳望远镜光学系统进行偏振优化设计非常必要.针对8 m中国巨型太阳望远镜(Chinese Giant Solar Telescope, CGST)的偏振设计需求,提出了基于四镜偏振补偿结构的望远镜折轴光学系统设计方案.基于偏振光线追迹方法,分析了该方案仪器偏振在望远镜光瞳和视场上的分布特性以及视场分布特性随望远镜运动和波长的变化.结果表明,在HeI 1.083μm和FeI 1.565μm磁敏谱线所在的近红外波段, CGST仪器偏振满足2×10^(-4)测量精度要求的“无偏振视场”为0.91′,而在可见光波段该“无偏振视场”为0.5′.Instrumental polarization is a vital factor for the accurate measurements of the solar magnetic field. It is necessary to optimize the optical design of the large solar telescope to obtain high accuracy solar magnetic field information. In this paper, an optimal design scheme based on four-mirror polarization compensation optics for the 8-meter giant solar telescope is presented. The polarization effect of pupil and field of view are analyzed by the polarization ray tracing programming, the telescope motion and wavelength properties of the field-effect are investigated detailedly. The result shows that, in the near infrared waveband which includes the magnetic sensitive spectral lines of HeI 1.083 μm and FeI 1.565 μm,the polarization-free field size is 0.91′, and the polarization-free field size in visible is 0.5′, in which the instrumental polarization of telescope is smaller than 2 ×10^(-4).

关 键 词：天文望远镜 仪器:高分辨率 技术:偏振测量 方法:数值模拟 

分 类 号：P111[天文地球—天文学]