白光日冕仪光学系统的杂散光抑制  

Stray light suppressing of optical system in white light coronagraph

作　　者：张红鑫[1] 卢振武[1] 夏利东[2] 刘华[1] 李萍[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所光学技术研发中心,吉林长春130033 [2]山东大学威海分校空间科学与物理学院,山东威海264209

出　　处：《光学精密工程》2009年第10期2371-2376,共6页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.40774080)

摘　　要：为满足日冕仪对杂散光抑制的苛刻要求,通过分析日冕仪的工作原理和结构特点,设计了白光日冕仪光学系统,系统观测范围为2.5~15 R⊙,角分辨率为14″,口径为30 mm,焦距为200 mm,系统总长为1 080 mm;其中光学系统长370mm,37 pl/mm的MTF值＆gt;0.5。分析了直射太阳光、太阳光在外掩体D1边缘的衍射光、视场光阑A1边缘的衍射光、以及物镜组O1各表面多次反射带来的系统杂散光的特点,利用多个光阑互相共轭的空间位置关系,设计了相应的杂散光抑制结构,从而完全抑制了系统的4个主要杂散光光源产生的杂散光,使系统整体杂散光抑制水平达到10-8~10-10B⊙,满足了日冕仪光学系统对杂散光抑制的要求。To meet the demands on suppressing strictly stray light for a coronagraph,a white corona- graph is designed based on its working principle and the properties of stray light. The white corona- graph shows its main specifications in the field of view of 2.5 Ro to 15 Ro ,a resolution of 14 ,a aper- ture of 30 mm,a focal length of 200 ram,and the total length of 1080 mm. Furthermore,the length of optical structure is 370 mm and the MTF value at 37 pl/mm is above 0.5. The four kinds of stray light sources is analyzed in detail, which is direct sun light, the diffractive light of sun light at edge of an external occulter D1 , the diffractive light of sun light at edge of a field stop A1 , and the multi-reflec- tion light in the objective O1. With the help of conjugated stops,a stray light suppressing structure is designed. Experiment results show that four main stray light sources are totally suppressed and the stray light suppressing level reaches 10^-8 --10^-10 B ,which satisfies the system requirements.

关 键 词：日冕仪 杂散光 光学设计 

分 类 号：TH703[机械工程—仪器科学与技术]