中阶梯光栅光谱仪采用中阶梯光栅与棱镜交叉色散结构, 在像面形成二维光谱。 影响中阶梯光栅光谱仪分辨率因素较多。 分析了针孔直径、 光栅参数、 棱镜参数、 CCD像素尺寸和像差对系统分辨率的影响, 得到针孔、 光栅、 CCD是影响系统分辨率的主要因素, 并推导三者在确定系统实际分辨率时相互制约的关系, 从而设计一种高分辨率轻小型中阶梯光栅光谱仪。 结果表明, 轻小型中阶梯光栅光谱仪像差得到充分校正, 分辨率达到设计要求。 通过对拍摄的汞灯谱图进行还原与标定, 实际分辨率为0.038 nm, 达到目标值(0.05@ 200 nm)的要求。 而普通的光栅光谱仪要达到这样的分辨率, 其焦距是500 mm左右, 充分体现轻小型的优势。

The present paper analyzed the influence of the pinhole diameter, grating parameters, CCD pixel size, prism parameters, system aberrations and found that the first three are the main factors, and then deduced the mutual restraint relationship among them. On this basis, a portable high-resolution echelle spectrograph was designed. Applying this design, aberration was fully corrected and spectral resolution achieved the demand. With the Hg lamp calibrated and restored, the actual resolution gets up to 0.038 nm which is significantly better than target (0.05@200 nm), while the ordinary grating spectrometers need 500 mm focal length to achieve this resolution. From this result, the advantages of the portable echelle spectrograph are fully demonstrated.