The new variable-groove-depth grating-type interferometer that was used to obtain experimental interferograms and spectra used for short and long wavelengths (λ< 15 µ to λ>4 mm), together with its construction and testing, is described.
JOHN STRONG and G. A. VANASSE, "Lamellar Grating Far-Infrared Interferomer," J. Opt. Soc. Am. 50, 113-113 (1960)