为了满足高分辨率大相对孔径宽波段高光谱成像仪的要求, 提出并设计了一种基于双Schwarzschild结构的平面光栅光谱仪。基于几何像差理论, 推导出了像散校正条件, 利用Matlab软件编制了初始结构参数快速计算程序。作为实例, 设计了一个相对孔径为1/2.5, 波段为350～1 000 nm的平面光栅光谱仪光学系统。利用自己编制的Matlab程序计算了初始结构参数, 然后利用光学设计软件ZEMAX-EE对该光谱仪的光学系统进行了光线追迹和优化设计, 并对设计结果进行分析。结果表明, 在整个工作波段(350～1 000 nm)内, 点列图半径均方根值小于8.2 μm, 实现了大相对孔径宽波段像散同时校正, 在宽波段内同时获得了良好的成像质量, 满足了设计指标要求。所提出的基于双Schwarzschild结构的平面光栅光谱仪在高光谱遥感领域很有应用前景。

To satisfy the requirements of a high-resolution hyperspectral imager with a large relative aperture and a wide spectral region, a new type plane grating spectrometer was proposed and designed based on double Schwarzschild structures. The astigmatism-correcting condition was derived based on the theory of geometrical aberration. The initial parameter computing was programmed by using Matlab software. As an example, an optical system for the plane grating spectrometer with a relative aperture of 1/2.5 operating in 350—1 000 nm was designed. The initial parameters were computed using proposed Matlab program, then the ray tracing and optimization for the spectrometer system were performed with ZEMAX-EE software. The analyzed results demonstrate that the spot radius(Root Mean Square, RMS) is less than 8.2 μm in the whole working waveband (from 350 nm to 1 000 nm), the astigmatism-corrected is realized, and good imaging quality is obtained in a wide spectral region with a large relative aperture. Obtained data satisfy the requirements of design specifications, and prove the feasibility of the new type plane grating spectrometer base on double Schwarzschild structures. It has extensive application prospects in spaceborne and airborne hyperspectral remote sensing fields.