SISYPHUS LASER COOLING OF TRAPPED IONS - THE TRANSITION FROM OPTICAL MOLASSES TO THE LAMB-DICKE REGIME

We consider the laser cooling of trapped ions on a J(g) = 1/2-J(e) = 3 /2 transition in a field of counterpropagating laser beams with perpen dicular linear polarizations. Applying numerical simulations of the cl assical atomic motion in internal-state-dependent potentials, we inves tigate the transition between the case of free particles and the Lamb- Dicke regime of particles confined to less than an optical wavelength by the trapping potential. Apart from the mean kinetic energies obtain able, we consider other issues of relevance to experiments: the relati on between the kinetic energies and the spatial extent of the ion moti on in the trap, and the effects of the Coulomb repulsion on cooling of several ions.