Collisional redistribution of radiation in strong fields: Modification of the collision dynamics

Abstract

We extend the theory of light scattering from an atom undergoing collisions to the case of strong laser fields, where the expansion in powers of $\Omega {\tau }_c$ that was used formerly in a series of papers by Burnett et al. breaks down. In particular we consider in detail the conditions necessary to relate the observable quantities to intense-field collisional rate constants in a dressed-state basis (such as those calculated by Light and Szöke). We also show (following Rabin and Ben-Reuven) that by studying the spectrum emitted by the atoms in the presence of a strong field one may measure the collisional rates for transfer between the dressed states of atom plus radiation field.