LASER COOLING OF TRAPPED IONS - THE INFLUENCE OF MICROMOTION

Laser cooling of a single trapped ion in a Paul trap is discussed theo retically in the Lamb-Dicke limit, with full consideration of the time dependence of the trapping potential. Resulting mean kinetic energies are defined as time averages over one period of the micromotion and a re compared with final temperatures expected from the laser cooling tr eatment with harmonic traps. For laser-atom detunings close to the mic romotion frequency the results differ significantly from those expecte d for a harmonic trap potential. A physical interpretation is given an d simple formulas are derived for the strong confinement case.