Loading dynamics of CO2 laser traps - art. no. 043403

We present a simple Fokker-Planck model for the evolution of the number of atoms and the spatial distribution in a CO2 laser trap which is loaded from a magneto-optical tray (MOT). Deep CO2 laser traps can achieve very high d ensities. but reach equilibrium slowly compared to shallow traps. Equilibri um times range from milliseconds for shallow traps to seconds in traps whic h are deep compared to the thermal energy. A universal function for the max imum number of trapped atoms is given, assuming that the optical dipole tra p reaches thermal equilibrium with the MOT.