New Fourier Transform All-Reflection Interferometer

Abstract

This paper describes the design and tests of an all-reflection two-beam interferometer. The interferometer consists of three reflecting diffraction gratings and two collimating mirrors. The use of only reflection optics eliminates the need for a transmitting beam splitter and compensation plate thus permitting the possibility of using the interferometer in the vacuum ultraviolet. This instrument can be used as a Fourier transform spectrometer. Obtaining the spectrum of the incident light from the interferogram is not so straightforward as with a Michelson interferometer. The method of Fourier inversion is described, and examples of interferograms taken with the instrument and the spectra obtained from the interferograms are presented. The interferometer has been tested in the visible and in the near ultraviolet at 2537 A.