INTERFERENTIAL SPECTROMETRY THROUGH AMPLITUDE MODULATION (SPECTROMETRE INTERFERENTIEL A SELECTION PAR L'AMPLITUDE DE MODULATION),

The paper combines two previous communications of the author and describes a new spectrometric method specifically adapted to the infrared. By replacing the two mirrors of the Michelson interferometer by two gratings having the same incidence and by linear variation as a function of time of the path difference between the two beams, it is possible to modulate, in a complex spectrum, a single element of width equal to the theoretical resolution limit of the grating. The solid angle of the effective beam is much larger than in a standard spectrometer so that the method furnishes a large increase of luminosity. The design and construction of prototype and the first findings with it are discussed. Author