We present a simple numerical procedure that allows the frequency-dependent absorption and dispersion line profiles to be extracted from the in-phase and in-quadrature components of a spectrum obtained by frequency-modulation techniques. The procedure is independent of the underlying line shapes and takes into account contributions by additional amplitude modulation. With the help of sum rules the parameters of this amplitude modulation can be determined.
© 1999 Optical Society of America
R. Wynands and A. Nagel, "Inversion of frequency-modulation spectroscopy line shapes," J. Opt. Soc. Am. B 16, 1617-1622 (1999)