| 摘要 |
A monochromator comprises a first and a second concave grating. An entrance slit is imaged by the concave grating in the plane as a spectrum. A disc comprises a spiral slot. A section of the slot forms an intermediate slit periodically sweeping transversely across the spectrum. A concave mirror images the fanning point of the concave grating. Thereby the fanned beams are recombined to a single beam. An exit slit is located in an image plane in which an image of the entrance slit is generated. The spectrum can be scanned quickly and cyclically without the gratings having to be rotated. There is also the effect of a double monochromator. Another embodiment comprises two concave mirrors to generate the image. |
