Multiechelle grating mountings with high spectral resolution and dispersion

This paper describes a new spectrometer mounting using several echelle gratings as dispersive elements. These gratings are mounted so that a resolution equal to the sum of the resolution of the individual gratings is obtained. In the mounting the dispersions from the gratings coact resulting in very high dispersion in the focal plane. The multiechelle grating mounting can be used to build compact spectrometers with higher resolutions than can be obtained with the widest gratings ever ruled. Results from an experimental verification of the multiechelle grating mounting are given.