THEORY OF SELECTIVE REFLECTION SPECTROSCOPY

We present a calculation of selective reflection spectroscopy, in which the reflection coefficient of a light beam from the interface of a dielectric and an atomic vapor is evaluated as a function of the light frequency. It is shown that the reflection signal depends critically on the spatial attenuation pattern of the refracted field inside the vapor. In the linear case, where the incident laser power is below the saturation limit, we show the dependence of the peak- and center-frequencies of the reflectivity line shapes on the atomic number density. In particular, we show that our self-consistent solution leads to a previously unrecognized line shift. The effects related to saturation and velocity-changing collisions between vapor atoms are also analyzed.