Two-dimensional atomic velocity selection by a resonantly enhanced Raman transition

A simple scheme for two-dimensional velocity selection is proposed and theoretically investigated. The scheme uses only two laser beams exciting stimulated Raman transition in a three-level atom. Parameters of velocity-selective π-pulse as well as velocity distribution of selected atoms are calculated. It is shown that the distribution width can be lower than the recoil velocity for the narrow transitions used. A feasible scheme for the accumulation of selected atoms in magnetic traps is discussed.