Design of two-dimensional (crossed) grating calculation in Czerny-Turner spectrometer with usage of freeform mirrors

摘要

The possibility of building a spectrometer based on a flat two-dimensional (crossed) grating is being considered. The most suitable layout for this is the Czerny - Turner, where a spectral image lies in the plane. In this paper an attempt to compensate for the transverse aberrations is made by using a diffraction grating with variable spacing grooves in both sections and aspheric mirror elements of layout, including ones having a freeform surface. Using crossed grating greatly simplifies the device layout and may be particularly effective when used in the ultraviolet and infrared regions of the spectrum, due to a small choice of transmissive materials for manufacturing spectral prisms. This paper gives examples of such case.