论平面光栅单色计的光学质量

本文包括下列结果:1.以矢量代数方法一般地讨论了狭缝形状和谱线形状的关系;导出了一般的角色散公式。2.讨论了由于光栅角倍率特点所残留的不对称象差及其校正方法和其他象差之值,并举出一个校正象差的例。3.探讨了完全校正象差的可能有的结构及其特性。 关键词：

ON THE IMAGE QUALITY OF PLANE GRATING SPECTROMETER

In this paper various factors influencing the image quality of plane grating spectrometer are discussed in detail. By means of vector elgebra a general formula is given for the form of the spectral lines in relation to the form of the entrance slit. A formula describing the angular dispersion of the spectral line resulting from a circular slit is also given. Investigation on the optical performance of the Ebert-Fastie grating spectrometer shows that among various residual optical aberrations, due to unsymmetrical disposition of the incident and diffracting beams with respect to the grating surface, coma is the most serious image defect. This can however be corrected by changing the focal length of one of its reflecting mirrors and placing it at a definite distance from the other mirror. It is also shown that residual aberrations can be well eliminated by placing an aspherical correcting plate near the grating surface. By the latter means there is the potentiality of greatly improving the performance of the instrument; either the volume of the instrument may be greatly reduced where shorter focal length optical systems can be used, or much better light gathering capacity can be achieved without sacrificing its monochrometicity when the spectrometer is used as a monochrometor.