大视场、超光谱分辨率、高空间分辨是光谱成像仪的发展方向，谱线弯曲和色畸变的抑制则是二维谱图信息准确提取的前提。提出了一种棱镜光栅光谱成像结构形式，并采用矢量方法构建了棱镜光栅组合色散元件的数学模型，优化了分光模块的结构参数，基于此组合色散元件设计了一个具有近直视光路结构的超光谱成像仪光学系统。该系统光谱范围为400~800 nm，入射狭缝长为14 mm，F数为2.4，其光谱分辨率达0.5 nm，调制传递函数(MTF)在探测器奈奎斯特频率68 lp/mm处均大于0.7，谱线弯曲和色畸变均小于1 μm，低于单个像素的13.5%。

Wide field, high spectral resolution and high spatial resolution are the development directions for the imaging spectrometer. However, in order to extract the two-dimensional spectral information accurately, spectral and spatial distortion needs to be controlled within a small fraction of a pixel. The prism-grating imaging spectrometer is proposed. The mathematical model of prism-grating component is constructed by means of the vector method, and the optimization of structural parameters is determined through analyzing quantitatively the spectrum distortion characteristics of different prism-gratings. The optical system of ultraspectral imaging spectrometers with a direct vision is devised base on the Prism-Grating component. The spectral coverage, slit length and F number of the system are visible light from 400 nm to 800 nm, 14 mm and 2.4, respectively. The results demonstrate that the spectral resolution is 0.5 nm/pixel, and the modulation transfer function (MTF) for different spectral bands are more than 0.7 at the Nyquist spatial frequency of plane array charge coupled device (CCD). Both smile and keystone are less than 1 μm, and reduced to 13.5% of a pixel.