基于凸面光栅的Offner型编码孔径多光谱成像光学系统设计

Optical Design of Offner Code Aperture Spectral Imaging System Based on Convex Grating

基于Offner型同心结构特点,设计了一种工作波段范围3.0~5.0μm,F/4的双通道中波红外编码孔径多光谱成像系统,该系统由望远物镜和Offner型分光系统组成,其中Offner型分光系统采用一个凸面光栅和一个球面反射镜实现了编码孔径系统的分光和合光。根据探测器和数字微晶阵列的参数,对系统各主要光学参数进行合理选取,最终确定凸面光栅的曲率半径为150 mm,周期30μm。整个系统在全视场的弥散斑控制在20μm以内,小于探测器像元大小,满足像质要求。

On the basis of characteristics of optical system of offner spectral imagers,dual-pass mid-wave infrared coded aperture multispectral imaging system is designed,which has a the range of spectral band 3.0~5.0μm,F/4.The system is composed of the telescope objective lens and offner beam splitter system.The offner spectrograph uses a near-concentric configuration,defined by two curved element,a grating and a single spherical reflector.On the basis of the parameters of CCD and DMD,the optical parameters are distributed reasonably.The grating is convex rectangle,with the radius of curvature of 150 mm,and the period of 30μm.The geometric spot size radii are less than 20μm.