Strong-field effects on light-induced collisional energy transfer

Abstract

We describe strong-field effects in a class of collisional energy-transfer processes occurring among atoms in a gas irradiated by a laser beam. The time evolution of the atomic system is evaluated by solving a system of differential equations, and by using the Magnus-Light expansion of the scattering matrix. Results from the two methods are then compared. The resulting spectrum is shifted in frequency towards the antistatic side, and the line shape becomes less asymmetric. All these theoretical predictions are based on the assumption that the motion of the atoms during the collision can be described by classical mechanics, with no appreciable change of the kinetic energy of the atoms.