摘要
针对日冕仪中对杂散光的抑制要求,分析了日冕仪系统中的三种杂散光,包括日冕仪物镜二次反射产生的鬼像点、日冕仪物镜散射点、以及日冕仪孔径光阑衍射光。利用光学建模软件对日冕仪系统进行仿真和分析,发现这三种杂散光的成像位置十分接近且不易区分,并会对系统的检测过程和检测结果产生干扰。根据仿真结果,给出了这三种杂散光的判定与抑制方法,并利用一台视场为±1.08 R⊙~±2.5 R⊙(R⊙表示太阳半径),工作波段为530.3~637.4 nm,通光口径为220 mm,系统总长为4321 mm的内掩式日冕仪进行了理论验证和实验对比,验证了判定方法的可行性。同时设计了掩体和鬼像遮拦结构对杂散光进行抑制,增加了日冕仪系统杂散光抑制的选择方案,提升了日冕仪杂散光检测的准确率。
The coronagraph is a scientific instrument developed to observe extremely faint coronal emission in the strong background of the solar disk.During the coronagraph observation and laboratory detection procedures,numerous non-imaging beams are present.The entrance of non-imaging beams into the detector has an adverse impact on the imaging contrast and these beams reaching the image plane are usually called stray light.In order to discern the subtle coronal signal,it is imperative for the coronagraph to effectively mitigate most forms of stray light present within the system.Due to the stark contrast in brightness between the corona and the solar photosphere,very strict requirements must be met in terms of the suppression of stray light to obtain reliable measurements.This paper primarily examines three forms of stray light within inner mask coronagraph systems as per the stipulations set forth by the requirements of the coronagraph,including the ghost images produced by the reflections from two surfaces of the objective,the scattering points from the objective,and the diffracted light from the aperture stop.The origins of the aforementioned three types of stray light can be attributed to the inherent characteristics of the solar corona system,and they can not be completely eliminated from the coronagraph itself.Therefore,alternative procedures must be implemented to effectively nullify the stray light prior to reaching the image plane.We simulate the coronagraph system using optical modeling software and plot the stray light propagation path within the optical system.Our analysis reveals that the propagation of the aforementioned three types of stray light in the optical system converges at multiple locations.Further,based on the corresponding propagation paths,we have established the respective intensity distribution patterns of the three types of stray light at their imaging location and the characteristics of these kinds of stray light are also analyzed.Upon conducting an in-depth analysis,it is discovered that
作者
黄玉鹏
张红鑫
丁悦
王泰升
HUANG Yupeng;ZHANG Hongxin;DING Yue;WANG Taisheng(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2023年第11期160-170,共11页
Acta Photonica Sinica
基金
国家自然科学基金(No.41627806)。
关键词
内掩式日冕仪
杂散光检测
光线追迹
鬼像
散射光
杂散光判定
Inner-occulted coronagraph
Stray light detection
Ray tracing
Ghost image
Scatter light
Stray light determination
