DETERMINATION OF REFRACTIVE INDEX SPECTRA BY FOURIER SPECTROMETRY

If a dispersive medium is introduced into one arm of a Michelson interferometer irradiated by a wide band of radiation, the two-beam interferogram contains detailed information about the variation of the complex refractive index of the medium with wave-number. Recent experimental work in the infra-red spectral region has shown that this information may be recovered to give the complex refraction spectrum of the material. Details of the mathematical theory and the necessary observations and computations are given, and illustrated by the results of recent investigations of the refraction spectra of specimens in each of the three material phases. © 1969.