传统Czerny-Turner结构的成像光谱仪存在固有的像散, 为选择合理的消像散结构。对现有的消像散方法进行了比较, 在不忽略光栅与准直镜和聚焦镜距离的情况下, 分析了传统Czerny-Turner光谱仪的零阶消像散条件, 推导出子午和弧矢焦长的表达式, 并利用MATLAB精确计算出零阶消像散的光学结构参数。此外, 分析了用超环面聚焦镜代替球面镜、加入柱面反射镜和柱面透镜等方法的消像散条件, 并在可见光波段分别对初始Czerny-Turner结构进行改进优化。所有方法在整个波段内都较好地校正了像散, 将平面光栅置于发散光路中的方法不引入复杂光学元件, 结构简单、加工成本低、易于装调, 最具推广价值。

The traditional Czerny-Turner structure of the imaging spectrometer has inherent astigmatism. In order to select a reasonable astigmatism structure, the existing astigmatism methods are compared. The zero-order condition of the traditional Czerny-Turner spectrometer is analyzed without ignoring the distance from the grating to the mirror. The expressions of the tangential and sagittal focal lengths are derived, and the optical structure parameters of the zero-order condition are calculated by MATLAB. In addition, the correction conditions of replacing spherical mirror with toroidal focusing mirror, adding cylindrical mirror and adding cylindrical lens are analyzed. The initial Czerny-Turner structure is optimized in the visible band. All the methods can correct astigmatism well in the whole waveband, the method of placing planar grating in the astigmatism path does not introduce complex optical elements. It has simple structure, low processing cost, easy to adjust and most suitable, and the highest popularized value.