大相对孔径长波红外离轴混合成像光学系统设计

Design of Low F-Number LWIR Off-Axis Hybrid Imaging Optical System

介绍了一种相对孔径为1/1.67的线阵长波红外离轴混合成像光学系统设计,系统采用二次成像结构形式,一次成像面前,通过大口径离轴折反镜组压缩光束口径,一次成像面后,通过小口径的折衍混合中继透镜组补偿系统像差。通过对光学系统优化设计分析,得到全视场传递函数在20 lp/mm处设计值优于0.45,全视场弥散圆均方根直径小于25μm,全视场畸变小于1%,像质优良。系统最大口径300 mm,可适用于多种平台的长波红外成像传感器。

A long wavelength infrared off-axis hybrid imaging optical system with 1.67 f-number is introduced.The secondary imaging structure is adopted in the system.The optical aperture is compressed by a large aperture off-axis refractive reflector set in front of the first imaging,and the aberration of the system is compensated by a small aperture hybrid refractive diffractive relay lens set after the first imaging.Through the optimization design analysis of the optical system,the transfer function value in full field of view is more than 0.45 at 20 lp/mm,the dispersion circle root diameter value in full field of view is less than 25μm,the full field of view distortion of the lens is less than 1%,and good image quality is got.The longest aperture of the system is 300 mm,which is suitable for long wavelength infrared imaging sensors on platforms.