MOMENTUM-TRANSFER IN LASER-COOLED CESIUM BY ADIABATIC PASSAGE IN A LIGHT-FIELD

We have observed transfer of momentum and ground state population in l aser-cooled cesium by adiabatic following of a slowly evolving Light f ield. In this new technique for mechanical manipulation of atoms, spon taneous emission is suppressed since the atoms evolve in a ''dark'' st ate that follows the light field. This means that the phase coherence of the atom is preserved so that this technique is useful in the reali zation of coherent atomic beam splitters and mirrors. Our experimental results are in good agreement with optical Bloch equation calculation s.