The entrance slit width of a diffraction-grating spectrometer often limits the light-grasp or etendue of the instrument. The etendue may be increased by the use of a wide grating or mosaic, or one with a large blaze angle. However, those methods are not the only ones available. Further developments may use two or more gratings in arrangements other than a mosaic. These arrangements may use the different gratings in separate beams or consecutively in the same beam.

Date Published: 9 January 1984
PDF: 6 pages
Proc. SPIE 0445, Instrumentation in Astronomy V, (9 January 1984); doi: 10.1117/12.966185

Published in SPIE Proceedings Vol. 0445:
Instrumentation in Astronomy V
Alec Boksenberg; David L. Crawford, Editor(s)