The Fabry-Perot (F.P.) interferometer can only be used in high-resolution infrared absorption spectroscopy if it is preceded by a monochromator isolating one single F.P. order and scanned in synchronism with the F.P. A S.I.S.A.M. spectrometer (as described by P. Connes) can play the part of the premonochromator. Such a spectrometer has been built, synchronous scanning achieved, and a resolving power R = 240,000 reached in the 1.6-μ region. Some spectra are shown (CH4, ICH3).
Georges Graner, "High-Resolution Absorption Spectroscopy in the Infrared with Fabry-Perot and S.I.S.A.M. Spectrometers," Appl. Opt. 4, 1620-1623 (1965)