插入Féry棱镜的小型Offner超光谱成像系统的设计

为了减小超光谱成像系统的质量和体积,校正光谱成像的谱线弯曲,提出了一种新型带有Féry曲面棱镜的Offner超光谱成像系统。在该系统中,一对Féry曲面棱镜位于Offner中继系统的两臂,光束两次通过Féry棱镜进行分光,因此当获得指定大小的色散值时该结构具有比传统结构更小的质量和体积。为了减小可见近红外(VNIR)光谱通道的非线性色散,在该结构中还引入一对消色差火石Féry棱镜。设计了应用于VNIR和短波红外(SWIR)两个光谱通道的超光谱成像系统,并给出了设计结果。结果表明,该光谱成像系统在两个光谱通道内的谱线弯曲均小于0.1个像元,色畸变均<0.045个像元,而非线性度小于0.1,可满足机载或星载超光谱成像仪的要求。

Design of compact Offner hyperspectral imaging system with Féry prism

In order to decrease the volume and quality of an imaging system and to correct the smile of a spectral image, a novel Offner hyperspectral imaging system with Féry prisms is presented. In this system,a pairs of Féry curved surface prisms are located at two arms of the Offner relay configuration and the light beam passes through the prisms twice to be dispersed. Therefore,the system shows a lighter and smaller structure as compared with conventional one when it gains a given dispersion value. To decrease the nonlinear dispersion of spectral channel in Visible-Near Infrared (VNIR), a couple of anti-dispersion flint Féry prisms are introducted into this system again. Then,two kinds of hyperspectral imaging systems applied to VNIR and Short-Wave Infrared (SWIR) channels are designed, respectively.The analytical results indicate the smiles and keystones of the two spectral imaging systems are less than 0.1 pixel and 0.045 pixel, respectively, and the nonlinearity is less than 0.1, which satisfies the requirements of airborne or spaceborne hyperspectral imagers.