针对目前国内对星载电离层成像光谱仪研究，设计了一种适用于120～180 nm远紫外探测的光学系统，并开展了原理样机的研制工作。对比国外各种方案，分析其优劣性后提出了以离轴抛物镜为物镜，Czerny-Turner结构为成像光谱系统的方案。为解决传统Czerny-Turner结构像差校正不均匀、空间分辨率低等缺点，进行了像差理论的研究，并提出了处理方法。设计成功了视场角为4°，焦距为139.3 mm，工作波段在120～180 nm之间的星载电离层成像光谱仪系统。设计结果表明，全系统的像差得到充分校正，全视场全波段调制传递函数值在0.6以上，完全满足指标要求。将该方案与国外已有载荷进行对比，证明其工程实现性好，性能更为优越。

An optical system applied to the detection of 120～180 nm far ultraviolet waveband is developed for the study of ionosphere imaging spectrometer carried by satellite in China. The programme that uses off-axis parabolic as objective lens and Czerny-Turner system as imaging spectrum system structure is proposed after comparing different foreign programmes. The aberration theory is studied and a novel method of aberration correction is deduced to overcome the disadvantages of Czerny-Turner structure such as non-homogeneous aberration correction and low spatial resolution. Spectrograph system operating in 120～180 nm waveband with 4°field of view and 139.3 mm focal length is designed. The results demonstrate that the aberration of the system is substantially corrected and the modulation transfer function (MTF) of total field of view is more than 0.6 in all waveband, which satisfies the requirement. Compared with foreign loads, the structure is more convenient and predominant.