紧凑型折反式制冷型中波红外成像光学系统设计  

Design of Compact Catadioptric Cooled Mid-Wavelength Infrared Imaging Optical System

作　　者：胡晨霞 刘英[1] 王成龙[1] 周广鹏 于晨 党博石[1] Hu Chenxia;Liu Ying;Wang Chenglong;Zhou Guangpeng;Yu Chen;Dang Boshi(Changchun Institute of Optics,Fine Mechanics,and Physics,Chinese Academy of Sciences,Changchun 130033,Jilin,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [2]中国科学院大学,北京100049

出　　处：《光学学报》2024年第9期219-230,共12页Acta Optica Sinica

摘　　要：为解决长焦距大口径红外成像光学系统长筒长、大体积、高成本的问题,设计了基于卡塞格林结构(卡式结构)的折反式制冷型中波红外成像光学系统。鉴于该类系统初始结构的确定缺乏充分的理论指导,推导了由拦光系数α、副镜放大率β_(sec)和中继镜组垂轴放大率β_(relay)三个关键参数表示的计算公式,包括光学系统初始结构参数、系统长度T值、卡式结构初级球差和初级彗差计算公式,分析了系统像差校正难度和紧凑性随α、β_(sec)、β_(relay)的变化规律。基于像差校正难度与结构紧凑性之间的相互矛盾关系,提出了关键参数的最佳取值方法,为确定系统初始结构提供了重要的理论指导。使用ZEMAX软件对初始结构进行设计优化,完成了一款焦距为-600 mm、F数为2的紧凑型折反式制冷型中波红外成像光学系统,系统实现了100%冷光阑效率,总长为428 mm,各视场调制传递函数(MTF)值在奈奎斯特频率处均大于0.4,并对系统进行了公差分析,验证了理论的正确性和系统可加工性。Objective Compared with visible light systems,cooled infrared imaging optical systems have better application effects in terrible climatic conditions.Compared with uncooled infrared imaging optical systems,they have higher detection sensitivity,longer viewing distances,and more excellent image quality.Therefore,the cooled infrared imaging optical systems are widely used in many fields,such as aerospace and military applications.Cooled infrared imaging optical systems with long focal lengths and large apertures have the problems of long barrel lengths,large volume,and high cost.To solve these problems and achieve a cold shield efficiency of 100%,the design of the catadioptric optical system is generally adopted,such as the Cassegrain-based catadioptric optical system.As sufficient theoretical guidance for determining the initial structure of such systems is lacking,we propose a method for optimal values of key parameters.We design a catadioptric cooled mid-wave infrared imaging optical system based on Cassegrain,which provides important theoretical guidance for the determination of the initial structure of this kind of system.Methods We derive the calculation formulas which are expressed by three key parameters:the shading coefficientα,magnification of the second mirror of Cassegrainβ_(sec),and the vertical magnification of relay mirrorβ_(relay),including the initial structure parameters of the optical system,the T value of system length,the primary spherical aberration,and the primary coma aberration of the Cassegrain system.The variation of the difficulty in correcting aberration and compactness of the system withα,β_(sec),andβ_(relay)are analyzed through derived calculation formulas.Based on the contradictory relationship between the difficulty in correcting aberration and compactness of the system,the optimal value method of key parameters is proposed.The initial structure of the optical system is determined by the optimal value method,and the initial structure is further optimized through ZEMAX.A catadi

关 键 词：折反式光学系统 二次成像 中波红外 像差理论 光学系统设计 

分 类 号：O436[机械工程—光学工程]