LASER COOLING OF TRAPPED 3-LEVEL IONS - DESIGNING 2-LEVEL SYSTEMS FORSIDE-BAND COOLING

Laser cooling of three-level ions of the cascade, vee, and lambda conf iguration is considered with simultaneous excitation on a weak and str ong transition. Choosing appropriate parameters for the Rabi frequenci es and the respective detunings allows one to eliminate adiabatically one of the levels. The thus designed two-level ion can acquire decay r ates GAMMA' smaller than the trap frequency nu such that sideband cool ing becomes possible and accordingly allows cooling of the ion to its lowest oscillator state [n] = 0 in the trap. Explicit expressions for the detunings and the Pabi frequencies for sideband cooling of the eff ective two-level system are derived.