摘要
折衍混合透镜具有重量轻和结构紧凑的特点,在空间光学仪器等方面有一定的优势。结合物镜设计要求的工作波段3.7~4.8μm、焦距64 mm和F数1.6等参数,采用了含有平面衍射微结构的3片式分离镜片,物镜总长度和重量得以明显减少,减少约40%。镜片选用了常用的红外光学材料硅和锗,设计对公差的要求较为宽松,得到的弥散斑半径小于9.5μm,各个视场的MTF值在17毫米线对处均达到0.8。硅平面镜表面的衍射微结构可以用4次套镀薄膜的方法来实现16个台阶,分析了衍射微结构可接受的加工误差范围。选用SiO和ZnS膜层来减少镜片表面反射损失,波段内物镜的光学效率达到93%。
Owing to the light weight and compact structure characteristics,the refractive-diffractive hybrid optical system plays an important role in space optical instruments.The working band,focus length and F number of the system are designed to be 3.7-4.8μm,64 mm and 1.6,respectively.By applying diffractive optical element to the three-separating lens,the total length and total weight have been reduced by 40%.Silicon and germanium,two commonly used materials in infrared optics,were used in this design.The fabrication tolerance is loose,which makes the fabrication easier.The diffuse spot radius is less than 9.5μm.The modulation transfer function(MTF)is larger than 0.8 at 17 lp/mm.The 16 steps of diffractive microstructure can be fabricated by repeating the process of combine masks and thin film deposition 4 times.The tolerance range of fabrication is analyzed.By applying SiO and ZnS thin films on the Si and Ge surface to reduce surface reflection,the transmittance of the lens reaches 93%.
作者
刘敏
刘定权
周晟
罗海瀚
张秋玉
LIU Min;LIU Dingquan;ZHOU Sheng;LUO Haihan;ZHANG Qiuyu(Shanghai Institute of Technical Physics,Chinese Academy of Sciences,Shanghai 200083,China;University of Chinese Academy of sciences,Beijing 100049,China)
出处
《红外技术》
CSCD
北大核心
2019年第10期918-923,共6页
Infrared Technology
关键词
折衍混合
物镜
衍射微结构
光学设计
薄膜
refractive-diffractive hybrid
objective lens
diffractive microstructure
optical design
thin films
