Linear and nonlinear selective reflection spectroscopy

We report on recent developments in selective reflection spectroscopy at a vapor interface. In FM linear spectroscopy, the long range van der Waals surface interaction, responsible for lineshapes distortions and shifts, is quantitatively well understood with respect to the nature of the dielectric surface. Pump‐probe saturation effects in reflection spectroscopy on a two‐level system offer alternate ways of probing surface interaction, while nonlinear reflection spectrsocopy on a three‐level cascade system provides a unique tool for probing in a vapor cell the velocity distribution of desorbing atoms.