相干色散光谱仪中像切分器的设计与优化  

Design and Optimization of Image Slicer in Coherent Dispersive Spectrometer

作　　者：王艺东 魏儒义[1,2,3,4] 谢正茂 张凯[5] 陈莎莎[1] WANG Yidong;WEI Ruyi;XIE Zhengmao;ZHANG Kai;CHEN Shasha(Xi′an Institute of Optics and Precision Mechanics of Chinese Academy of Sciences,Xi′an 710119,China;University of Chinese Academy of Sciences,Beijing 100049,China;School of Electronic Information,Wuhan University,Wuhan 430064,China;Spectroscopy and Imaging Instrument Engineering Technology Research Center of Hubei Province,Wuhan 430064,China;Nanjing Institute of Astronomical Optics&Technology of Chinese Academy of Sciences,Nanjing 210042,China)

机构地区：[1]中国科学院西安光学精密机械研究所,西安710119 [2]中国科学院大学,北京100049 [3]武汉大学电子信息学院,武汉430064 [4]湖北省光谱与成像仪器工程技术研究中心,武汉430064 [5]中国科学院南京天文光学技术研究所,南京210042

出　　处：《光子学报》2022年第9期365-372,共8页Acta Photonica Sinica

基　　金：国家自然科学基金(No.11727806)。

摘　　要：像切分器是天文高透过率光谱仪中的重要光学器件之一,可以有效提高仪器的分辨率和能量透过率,但对其成像缺陷问题的研究较少。本文重点研究了目前广泛应用的Bowen⁃Walraven型和简化型像切分器中存在的切分像离焦和物点重复两类成像缺陷,发现这两种缺陷造成了实际切分像宽大于理论像宽,降低了系统的能量透过率和分辨率。为了降低成像缺陷对系统的影响,本文针对用于系外行星探测的相干色散光谱仪系统,分析了反射腔厚度和入射角与离焦和物点重复两类问题的关系,推导了光学反射腔厚度的通用设计公式。同时针对项目需求,仿真模拟了不同焦比和切分数量下的离焦和物点重复情况,发现在F/24和45°入射角条件下,切分像的离焦和物点重复现象较为均衡,是相对理想的选择。该结论为高分辨率光谱仪中像切分器的设计提供了通用设计思路,具有较重要的应用参考价值。Image slicer is an important optical device in astronomical observation spectrometer.It can effectively improve the resolution and energy transmittance of the instrument.The image slicer can divide the circular image spot into strips and arrange the strips in a straight line,so that all the image spots can pass through the spectrometer slit.Image slicers are commonly used in astronomical observation spectrometers to help instruments achieve high spectral resolution with medium apertures.Image slicers can be divided into 4 categories according to their working principles.Among them,Bowen-Walraven type is the most widely used image slicer type.Coherent dispersive spectroscopy is a technique that combines an interferometer and an intermediate resolution spectrometer.It measures the phase change of the interference fringes of the stellar spectral lines after the Doppler frequency shift,and calculates the radial velocity change of the star and the mass of the planet.Since the phase difference has a certain amplification factor relative to the wavelength offset,when the spectral resolution is the same,the radial velocity detection accuracy of the coherent dispersion technique can be greatly improved compared with the traditional echelle grating method.This paper is based on the coherent dispersive spectrometer used to detect exoplanets by the radial velocity method.The radial velocity detection accuracy is expected to be less than 1 m/s,and the detection target is K/M dwarf stars.The structure of the coherent dispersion spectrometer consists of collimating mirror,Sagnac interferometer,imaging mirror group,image slicer,relay mirror group,slit,dispersion grating and CCD.The working spectral range of the spectrometer is 660~900 nm,the system transmittance at the center wavelength is about 0.4,and the spectral resolution is 0.03 nm.In order to meet the requirements of energy utilization and spectral resolution,the system needs to use the image slicer to realize the target surface multiplexing of the CCD and the reasonable

关 键 词：相干色散光谱仪 像切分器 Bowen⁃Walraven型 离焦量 透过率 

分 类 号：P111.33[天文地球—天文学]