Abstract

Reflection spectroscopy of resonant gases was introduced by Wood as early as 1909. The idea underlying this method is simple: the anomalous dispersion in the spectral neighborhood of the absorption line manifests itself in a selective reflectivity of the boundary between a transparent dielectric material and a vapor. The technique, however, was not used very frequently until it was recognized that the recorded selective reflection spectra are Doppler free. Since then, numerous efforts have been undertaken to use selective reflection of the interface between a gas and a transparent solid for nonlinear optics¹ as well as for the study of surface properties² and collisional processes.²

© 1994 Optical Society of America