Selective reflection spectroscopy at a vapour calcium fluoride interface

The universal long-range van der Waals type atom-surface attraction was demonstrated to be susceptible of a resonant enhancement (with a possible change sign) when the virtual atomic emission can resonantly couple to a virtual absorption process in a surface mode. Presently, we investigate in the same cell the SR spectrum on the transition of interest for testing a resonant temperature dependence of the van der Waals interaction.