折/衍混合的红外双视场光学系统设计

Design of Hybrid Refractive-Diffractive Dual Field of View Infrared Optical System

为了实现红外双视场光学系统两个视场间的快速切换,同时满足便携式及易安装的需求,设计了一种轻量化的折/衍混合红外双视场光学系统.系统采用折/衍混合和二次成像光学结构,利用光学设计软件对系统进行优化,评价了系统的像质,分析了系统温度补偿问题并给出其温度调焦曲线.系统工作波长为3.7～4.8μm,能实现120mm/60mm两档焦距变换.设计结果表明,冷光阑效率达到100%,在探测器的Nyquist频率33lp/mm处,轴外视场光学系统的调制传递函数大于0.3,系统光学总长为200mm.整个系统包括7块透镜,只需移动一片透镜就能完成双视场的转换,结构简单,实现了轻量化和高质量成像.

In order to switch the dual Field of View Infrared optical system quickly,and satisfy the requirements of the portability and installation,a lightweight hybrid refractive-diffractive dual FOV IR optical system is designed.The system adopts re-imaging and hybrid refractive-diffractive system,is optimized by optical design software,and the image quality is also evaluated.The temperature compensation is also analyzed,and the temperature compensation curves are also shown.The system can be switched from 120 mm/60 mm and the work wavelength is between 3.7～4.8 μm.The results indicate that the efficiency of the cold shield is 100%;at the Nyquist frequency 33 lp/mm of the detector,the MTF of the off-axial field is higher than 0.3,and the system＇s optical length is 200 mm.The whole system consists of 7 pieces of lenses,and the dual FOV can be switched by shifting only one piece of them,which makes the system simple,lightweight with high quality imaging.