MANY-PARTICLE EFFECTS IN LASER COOLING OF ONE-DIMENSIONAL OPTICAL MOLASSES

We analyze the influence of long-range dipole-dipole interactions betw een atoms with Zeeman substructure on atomic polarization-gradient coo ling at low laser power. The system we consider is a cloud of N atoms driven by two counterpropagating linear cross-polarized laser beams (l in perpendicular to lin configuration) on a 1/2-3/2 transition. In the semiclassical regime we derive analytical results for the change of t he cooling force due to collisions and for the diffusion coefficient i n the far-field approximation. For the energy regime where the center- of-mass motion is characterized by oscillations in the optical potenti als, we estimate the effect of these far-field collisions on the motio n-induced sideband structure of the resonance fluorescence spectrum by using a white-noise approximation for the background light field. Thi s gives a qualitative signature of the heating mechanism in such syste ms.