结合三反消像散光学系统的中阶梯光栅光谱仪设计  

Design of Echelle Spectrometer with a Three-Mirror Anastigmat System

作　　者：张尹馨[1,2] 段文浩 李婉卓 Zhang Yinxin;Duan Wenhao;Li Wanzhuo(Key Laboratory of Opto-Electronics Information Technology of Ministry of Education(Tianjin University),Tianjin 300072,China;School of Precision Instruments and Optoelectronics Engineering,Tianjin University,Tianjin 300072,China;Science and Technology on Electro-Optical Information Security Control Laboratory,Tianjin 300308,China)

机构地区：[1]光电信息教育部重点实验室(天津大学),天津300072 [2]天津大学精密仪器与光电子工程学院,天津300072 [3]光电信息控制和安全技术重点实验室,天津300308

出　　处：《天津大学学报（自然科学与工程技术版）》2022年第5期519-526,共8页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(61505143);国家重大科学仪器设备开发专项资助项目(2014YQ510403)。

摘　　要：中阶梯光栅因其具有高分辨率、高衍射级次和全谱闪耀等特性,能够实现宽波长范围内的高分辨率全谱直读,常用于天文光谱仪及高端商用光谱仪中.然而,中阶梯光栅的衍射因为级次重叠严重,需要交叉色散形成二维光谱成像于面阵探测器.使用单一成像镜的二维靶面成像很难保证像面像质均匀,进而造成全谱范围内分辨率差异大,特别是边缘波长处分辨率明显降低的问题.为解决这一难题,本文提出了一种结合三反消像散光学系统的折叠型中阶梯光栅光谱仪方案(echelle spectrometer with three-mirror anastigmat,ESTMA),以三反消像散光学系统的3面反射镜代替常规中阶梯光栅光谱仪设计中的单成像反射镜.复色光经过入射小孔后被离轴抛物面镜准直,再由中阶梯光栅色散,用反射棱镜进行交叉色散,最后由三反消像散光学系统成像于面阵探测器.设计光谱范围为200~600 nm,焦距为350 mm.设计通过Zemax光学设计软件进行仿真及优化,结果显示,相对于单成像镜设计,ESTMA方案的全谱范围内像斑大小均匀,点列图均方根半径小于1μm,全波段仿真分辨率小于30 pm.在自建的实验平台上进行验证,实验结果表明,系统在253.652 nm、365.015 nm、404.656 nm、435.833 nm、546.074 nm处的实测分辨率分别为23.42 pm、23.46 pm、27.20 pm、32.74 pm和40.92 pm,除中心波长以外的实测波长分辨率显著优于单成像反射镜设计的理论分辨率,光谱仪的分辨率整体提升.Due to the characteristics of high resolution,high diffraction order,and full spectrum blaze of echelle grating,a spectrometer that uses the echelle grating as the dispersion element can achieve high resolution and full spectrum direct reading in a wide wavelength range.Therefore,an echelle grating is often used in astronomical and high-end commercial spectrometers.However,owing to the serious order overlap,the diffraction of the echelle grating needs cross-dispersion to form a two-dimensional spectral image on the area array detector.Moreover,the uniformity of the image quality is difficult to ensure using a single imaging mirror in the two-dimensional imaging process because it causes resolution differences at the full spectrum,especially at the edge wavelengths.To solve this problem,this paper develops a folding echelle spectrometer scheme with a three-mirror astigmatism optical system(ESTMA).The three mirrors of ESTMA are used to replace the single imaging mirror in the design of the conventional echelle grating spectrometer.After passing through the incident aperture,the polychromatic light is collimated by the off-axis parabolic mirror,which is then dispersed by the echelle grating,cross-dispersed by the reflecting prism,and finally imaged by the ESTMA on the area array detector.The spectral range of the spectrometer is 200—600 nm and the focal length is 350 mm.The designed optical path is simulated and optimized by the ZEMAX optical design software.Simulation results show that compared with the single imaging mirror design,ESTMA has a more uniform image spot size in the full spectrum range.The root mean square radius of the plot is less than 1μm and the overall simulation resolution is less than 30 pm.The scheme is experimentally verified and the results show that the measured spectral resolutions of the system at 253.652 nm,365.015 nm,404.656 nm,435.833 nm,and 546.074 nm are 23.42 pm,23.46 pm,27.20 pm,32.74 pm,and 40.92 pm,respectively.Except the center wavelength,the measured spectral resolution is si

关 键 词：中阶梯光栅光谱仪 三反消像散光学系统 交叉色散 二维谱图 

分 类 号：TH744.1[机械工程—光学工程]