宽温度范围内折衍混合中波红外消热差光学系统设计  

Design of refractive-diffractive hybrid medium wave infrared thermal suppression optical system in a wide temperature range

作　　者：彭远 魏鸿达 刘洋[1,3,4] 张建文 邓伟杰[1,3,4] 付强 PENG Yuan;WEI Hongda;LIU Yang;ZHANG Jianwen;DENG Weijie;FU Qiang(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Applied Optics,Changchun 130033,China;Key Laboratory of Advanced Manufacturing for Optical Systems,Chinese Academy of Sciences,Changchun 130033,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 [3]应用光学国家重点实验室,吉林长春130033 [4]光学系统先进制造重点实验室(中国科学院),吉林长春130033

出　　处：《红外与激光工程》2024年第10期193-203,共11页Infrared and Laser Engineering

基　　金：中国科学院青年创新促进会资助项目(2021221)。

摘　　要：在军事领域应用的红外光学系统,有时需在近200℃的宽温度范围内工作。这一温度范围内,红外光学材料可选的种类进一步减少,系统的热离焦现象也会更为严重,进而导致光学系统难以完成良好的无热化设计。为应对这一挑战,该研究将具有独特消热差和消色差特性的衍射元件加入光学系统设计中,并提出了一种针对二次成像系统的材料选择方法。此方法以理想光学系统为基础,利用等效透镜理论将光学系统中的物镜组和中继镜组均等效成由两个单透镜组成的镜组,进而利用T-C图完成对这两个镜组的材料优选。经过深入的分析与评价,最终确定物镜组采用IRG24和ZnS材料组合为最优方案,而中继镜组的最佳材料组合为IRG22和IRG24。依据此种材料组合和理想光学系统的光焦度分配,该研究设计完成了一套中波红外光学系统。该系统的工作波长为3.7~4.8μm,视场角为10°×8°,F数为2,焦距为55 mm,系统总长约为115 mm,冷阑效率达到100%。在20~220℃范围内,全视场的调制传递函数(MTF)均接近衍射极限,维持了良好的成像性能。Objective Infrared optical systems used in the military field sometimes need to operate in a wide temperature range of nearly 200℃.In this temperature range,the optional types of infrared optical materials are further reduced,and the thermal defocusing phenomenon of the system will be more serious,which leads to the difficulty of the optical system to complete a good non-thermal design.To address this challenge,diffractive elements with unique thermal and achromatic properties are added to the design of optical systems,and a material selection method for secondary imaging systems is proposed.Based on the ideal optical system,the objective lens group and the relay lens group in the optical system are equivalent to the mirror group composed of two single lenses by the equivalent lens theory,and then the material selection of the two mirror groups is completed by the nonthermal map.After in-depth analysis and evaluation,it is determined that the optimal material combination of IRG24 and ZnS for objective lens group is IRG22 and IRG24 for relay mirror group.According to the combination of materials and the distribution of focal power of the ideal optical system,a set of medium-wave infrared optical system is designed.The working wavelength of the system is 3.7-4.8μm,the field of view is 10°×8°,the F number is 2,the focal length is 55 mm,the total length of the system is about 115 mm,and the cold stop efficiency reaches 100%.In the range of 20-220℃,the modulation transfer function(MTF)of the whole field of view is close to the diffraction limit,and good imaging performance is maintained.Methods An optical system capable of good imaging in the temperature range of 20℃to 220℃has been established(Fig.4).The optical system adopts the method of secondary imaging.In order to better correct the advanced color difference and achieve the miniaturization of the system,diffractive elements and higher-order aspheric surfaces are added to the optical system.Finally,MTF function is used to evaluate the imaging quality o

关 键 词：光学设计 中波红外 T-C图 衍射元件 

分 类 号：E92[军事—军事装备学] TN219[兵器科学与技术—武器系统与运用工程]