MOTION OF A 2-LEVEL ATOM IN AN OPTICAL CAVITY

A semiclassical model of the force and momentum diffusion on a point p article is used to describe the motion of a two-level atom strongly co upled to a single Gaussian cavity mode. The effects of the momentum di ffusion on the motion of an atom in a cavity are investigated in a reg ime similar to that of the experiment performed by Mabuchi et al. [Opt . Lett. 21, 1393 (1996)]. It is found that a slow atom quickly develop s significant velocities along the cavity axis. The limited bandwidth in the experiment of Mabuchi et al. means that the full intensity sign al due to atomic motion in the standing wave is filtered leading to th e apparently smaller velocities observed. It is shown that a negative detuning of the laser and cavity from the atomic resonance would lead to nonzero dipole forces and significantly reduced velocities along th e standing wave. An analysis of the intensity signal with a larger ban dwidth is proposed, which would track the velocity of the atom along t he cavity axis. These results are compared with a Monte Carlo wave-fun ction simulation similar to that used to treat Doppler cooling.