制冷型折衍混合双波段红外光学系统无热化设计  

Athermalization Design of Cooled Refractive-Diffractive Hybrid Dual-Band Infrared Optical System

作　　者：聂怀乐 毛珊 赵建林[1] Nie Huaile;Mao Shan;Zhao Jianlin(Key Laboratory of Light Field Regulation and Information Perception,Ministry of Industry and Information Technology,School of Physical Science and Technology,Northwestern Polytechnical University,Xi'an 710129,Shaanxi,China)

机构地区：[1]西北工业大学物理科学与技术学院光场调控与信息感知工业和信息化部重点实验室,陕西省光信息技术重点实验室,陕西西安710129

出　　处：《光学学报》2023年第8期375-383,共9页Acta Optica Sinica

基　　金：国家自然科学基金(61927810,61905195);中国科学院光谱成像技术重点实验室开放基金(LSIT202006W);西北工业大学中央高校基本科研业务(310202011QD001);西安市青年人才托举项目(095920201316)。

摘　　要：基于衍射元件的特殊成像性质,使用双层衍射元件进行双波段红外光学系统设计已成为研究热点。使用双层衍射元件能够有效提升宽波段的衍射效率,在简化系统结构的基础上提高像质。将红外成像系统设计为制冷型结构,能够消除背景噪声干扰,保证100%的冷光阑效率。基于带宽积分平均衍射效率最大化方法,设计了一款含有双层衍射元件的制冷型双波段红外光学成像系统,实现了在双波段红外和宽温度范围下的无热化设计。光学系统含有三片透镜,仅由两种材料组成,入瞳直径为80 mm,焦距为100 mm,F数为1.25,有效视场为6°,工作波段为3.7~4.8μm和8.0~12.0μm,工作环境温度为-40~60℃。分析结果表明,在整个温度范围内,在17 lp/mm截止频率处,双波段红外光学系统所有视场的调制传递函数分别高于0.78和0.59,同时双层衍射元件在红外双波段的带宽积分平均衍射效率分别为99.35%和98.73%,综合带宽积分平均衍射效率为99.04%。此光学系统的结构设计简单,成像质量好,在军事和商业应用中具有一定优势。Objective Based on the special imaging properties of diffractive optical elements(DOEs),the design of refractivediffractive hybrid imaging optical systems has become a hotspot.Since infrared optical materials are rare,especially in dual bands or even multiple bands,available infrared materials are even rarer.Then,DOEs in these systems are necessary for color and thermal aberration correction among their special imaging properties,which can improve image quality,optimize the structure,and reduce the cost of infrared optical systems.Compared with the single-layer DOE,the double-layer DOE can greatly improve the diffractive efficiency of the wide waveband,which promotes the development and application of refractive-diffractive hybrid optical systems.In addition,most infrared optical systems designed in the existing references are uncooled.However,the uncooled infrared optical system has low cold stop efficiency,and its imaging can be easily disturbed by the background noise.In contrast,the cooled infrared optical system is matched with the cooled detector and has high detection sensitivity,which can guarantee a cold stop efficiency of 100%.Therefore,it is necessary to design a cooled dual-band infrared imaging optical system.We hope that our design and results can be helpful for dual-or multiband infrared imaging optical systems,especially for their application in a wide ambient temperature range.Methods In order to ensure the high diffraction efficiency of a double-layer DOE caused by ambient temperature change,the optical thermal expansion coefficient of substrate materials should be reasonably selected.After comparing different infrared optical materials,we select chalcogenide glass(IRG24)and zinc sulfide(ZnS)as double-layer DOE substrate materials based on the bandwidth integral average diffraction efficiency(BIADE)maximization design and Matlab software simulation.Then,optimal design wavelengths are selected,and the corresponding micro-structure heights and diffraction orders are calculated.Finally,based on the

关 键 词：光学设计 衍射元件 双波段红外 衍射效率 无热化 

分 类 号：O436[机械工程—光学工程]