On the Correction of Phase Errors in Interferograms

Abstract

When an interferogram is an even function of path difference, it suffices to compute the cosine Fourier transform of the interferogram from zero to D the maximum path difference, to produce the spectrum. If the computation does not start from exactly zero path difference, there is a phase error, which leads to asymmetry of the scanning function and, in the case of continuous spectra, distortion of the base line. The phase error may best be corrected by introducing a corresponding phase correction into the transforming cosine function. Taking the total transform, T=C2+S2 leads to a symmetric scanning function which has rather broad wings.