Optical system of a compact double-dispersion monochromator based on concave stigmatic diffraction gratings

A new optical system is proposed for a double-dispersion monochromator base d on concave stigmatic diffraction gratings with a variable ruling step and distinguished by high angular dispersion, a small number of optical compon ents (one grating and one mirror), and simplicity of the kinematic system ( the spectrum is scanned by simply rotating the mirror). Various versions of the optimization of the parameters of the optical system and the grating u sed in it are considered. It is shown that the mirror by means of which the spectrum is scanned can be concave, flat, or convex. (C) 1998 The Optical Society of America. [S1070-9762(98)01412-2].