Instrument line shape of Fourier transform spectrometers: analytic solutions for nonuniformly illuminated off-axis detectors

Abstract

A simple and powerful method for obtaining analytic instrument line shapes (ILS's) for Fourier transform spectrometers is explained. ILS's for off-axis circular and rectangular detectors are calculated to illustrate the method. Results match earlier ILS simulations. The contribution of the nonuniformity of light intensity across the detector surface is also taken into account.