基于FOSC型的宽波段高效率中低色散光谱仪设计(特邀)  

Optical Design of a High-efficiency Medium-low Dispersion Spectrograph with Wide-band Based on FOSC Type(Invited)

作　　者：季杭馨[1,2] 巴国鑫 李军 余浩然[1,2] JI Hangxin;BA Guoxin;LI Jun;YU Haoran(National Astronomical Observatories/Nanjing Institute of Astronomical Optics&Technology,Chinese Academy of Sciences,Nanjing 210042,China;CAS Key Laboratory of Astronomical Optics&Technology,Nanjing Institute of Astronomical Optics&Technology,Nanjing 210042,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院国家天文台南京天文光学技术研究所,南京210042 [2]中国科学院天文光学技术重点实验室,南京210042 [3]中国科学院大学,北京100049

出　　处：《光子学报》2023年第5期70-81,共12页Acta Photonica Sinica

基　　金：国家自然科学基金(No.12173061)。

摘　　要：为实现各类暂现源及暗弱目标的宽波段、高效率光谱后随观测,以1.9 m光学望远镜为例,设计了一种基于Faint Object Spectrograph and Camera型的双通道中低色散光谱仪,可实现三种光谱分辨率(R=500、2000和5500),工作波段覆盖紫外-近红外(310~1000 nm)。根据光栅方程和光谱分辨率等各项指标,确定光谱仪的初始结构参数,针对光谱仪在全波段的高效率需求以及仪器随动的包络限制,确定光学系统采用双通道设计并近似对称分布:准直系统采用了不同于传统Faint Object Spectrograph and Camera型光谱仪的折反射式系统,在提高了系统效率的同时压缩了空间。色散系统根据直视棱栅的不同工艺,通过棱镜材料和角度的调整对工作波段的光栅效率进行优化并得到8种棱栅参数;红蓝通道相机系统在设计过程中优化选取光学材料,同时结合二次非球面和单透镜的主动调焦补偿,实现大动态温度范围(-30℃~20℃)全视场(φ16°)最大弥散斑半径均方根小于5μm的优良像质。该系统结构紧凑、分布对称,设计结果满足各项指标,光谱仪全波段峰值效率优于60%,最低效率优于20%,具有较高的可实现性。基于曲面芯片工艺,以红通道为例,简化的相机系统至少可提高整体光谱效率约4%,可以为未来光谱仪相机系统的设计提供参考。Modern astronomy has entered a new era of all-band,multi-messenger,and space-ground synergistic observation.Optical/Infrared telescopes and their instruments have an increasing demand for high-tech innovation.Any advanced technology and process that can improve the sensitivity,extent and accuracy of detection as well as reduce the volume and cost should be concerned by the instrument design.Several ground/space-based optical surveys telescopes,such as Large Synoptic Survey Telescope,Roman Space Telescope,Euclid,and China Space Station Telescope will commission in the following five years.The upcoming massive deep sky survey data will make optical astronomy enter an unprecedented development epoch.The astronomical community hopes to build various advanced astronomical instruments to explore and investigate any objects among the different scales of the universe.The hottest research in time-domain astronomy is the identification and characteristic analysis of various transient sources,such as Gravitational-Wave Electromagnetic Counterparts,silent Black-Hole flares,and Gamma-Bursts,so it needs the spectrograph have the capability of fast response,wide-band and high efficiency with one exposure.What's more,if the instrument has multi-mode,like,multi-color imaging,spectrograph with different resolution mode,polarimetry,it will be very popular to the community.The mid-low dispersion imaging spectrometer always has the characteristics of multi-modes,high efficiency and small volume,which is suitable for the optical band following-up observation of various transient targets.This kind of instrumentation is a workhorse spectrograph for all size of telescopes around the world,such as,Low Resolution Imaging Spectrometer at Keck I telescope,Focal Reducer and Spectrograph-2 at VLT,Faint Object Camera and Spectrograph(FOCAS)at Subaru Telescope,ESO Faint Object Spectrograph and Camera at 3.6 meters telescope.However,the working band of these spectrographs is mainly visible(365~900 nm).What's more,the“FOSC”type of spectrometer

关 键 词：棱栅 天文光谱仪 中低色散 体位相全息光栅 曲面探测器 紫外 

分 类 号：P111.42[天文地球—天文学]