凸面锗窗口亚波长抗反射结构的设计与制备  

Design and Fabrication of the Antireflection Subwavelength Structure of Convex Germanium Optical Window

作　　者：陈佛奎 丁江 余明 马翠[2] 林慧[2] Chen Fokui;Ding Jiang;Yu Ming;Ma Cui;Lin Hui(School of Mechanical Engineering,Guangxi University,Nanning 530004,Guangxi,China;Shenzhen Institute of Advanced Technology,Chinese Academy of Sciences,Shenzhen 518055,Guangdong,China)

机构地区：[1]广西大学机械工程学院,广西南宁530004 [2]中国科学院深圳先进技术研究院,广东深圳518055

出　　处：《激光与光电子学进展》2023年第5期222-227,共6页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(U1713210);深圳基础研究计划(JCYJ20170818163928953)。

摘　　要：红外光学成像系统的灵敏度与光学窗口透射率密切相关,锗窗口是红外光学系统的常用窗口,在锗窗口上制备亚波长结构可以增强抗反射性能从而提高透射率,且常选择凸面窗口以获得更大的视场角。针对在曲面窗口上亚波长结构的制备工艺较为复杂的难题,本文运用柔性紫外纳米压印方法(soft UV-NIL),在凸面锗窗口表面高效、高质量地制作了亚波长抗反射结构。首先基于时域有限差分方法优化设计了亚波长抗反射结构参数,然后基于soft UV-NIL工艺制备了符合设计要求的亚波长结构。测试结果表明,在3.55~5.55μm波长范围内,凸面锗窗口单面平均透射率由65.81%提升到78.68%,在波长为4.4μm处,透射率由65.85%提升至83.13%,实现了中红外宽波段抗反射效果。The sensitivity of infrared optical imaging systems is closely related to the transmittance of optical windows,and Ge windows are commonly used windows in infrared optical systems.Fabrication of subwavelength structures on Ge windows can enhance the antireflection performance so as to improve the optical transmittance,and the Ge windows are usually convex shaped to get a larger field angle.However,based on current methods,it is difficult and complicated to fabricate subwavelength structures on curved windows.To solve this problem,this study presented an efficient and highquality way to fabricate subwavelength antireflection structures on the convex Ge window based on soft ultraviolet nanoimprint lithography(soft UVNIL).The parameters of the subwavelength antireflection structures were optimized based on the finitedifference timedomain method first.The subwavelength structures were fabricated on the convex Ge window by soft UVNIL.Test result shows that the average singleside transmittance of the convex Ge window is raised from 65.81%to 78.68%in the region of 3.55-5.55μm,and specifically,from 65.85%to 83.13%at the wavelength of 4.4μm.As a result,the broadband antireflection performance in midinfrared is realized.

关 键 词：光学设计 微结构制造 亚波长结构 柔性紫外纳米压印 抗反射 

分 类 号：O485[理学—固体物理]