Origin of the "blueshift" in selective reflection spectroscopy and its partial compensation by the local-field correction - art. no. 063813

The theory of selective reflection from the interface of a dielectric mediu m and an atomic vapor is reconsidered. Both the local-field correction and the nonexponential decay of the electromagnetic field inside the vapor are accounted for in a purely analytical form. It is shown that the large influ ence of both effects on the shift of the spectral line is due to an interfe rence between contributions from atoms moving towards the reflecting surfac e and from those moving away. We show that the local-field correction reduc es the blueshift due to the field decay by one-third of its value. A simple formula relating the shift of the maximum of the reflection spectrum to th e transition dipole moment and the number density of the atoms is given.