Control of spectral aberrations in a monochromator using a chirped grating

摘要

A method is proposed to minimize the impact of spectral aberrations in a monochromator based on a rectilinear translation of a plane chirped grating. The chirped grating, that has a spatially variable groove spacing, is used to diffract and to spectrally focus the radiation. The expression of the width of the instrument line shape due to aberrations have been developed in order to obtain the optimal rectilinear trajectory required to operate the monochromator without significant spectral aberrations. Experimental measurements of the emission spectrum of a five-wavelength Helium-Neon laser are presented, as well as the sensitivity of the monochromator performance to different geometrical parameters.