Abstract
We consider the deflection of a three-level atom of Λ-type interacting with a light field of two coherent laser beams. We employ the dressed state formalism, which is suitable for large Rabi frequencies and or large detunings. A full study of the interaction and relaxation processes is performed. We show that a beam of atoms is split into three beams once it crosses the light field. This is a three-state version of the well-known optical Stern-Gerlach effect, which has been theoretically studied and experimentally demonstrated for two-level atoms. Under coherent population trapping conditions, the splitting of the beam becomes twofold. This gives us, in principle, the opportunity of a mechanical demonstration of the coherent population trapping effect.