EXPERIMENTAL DEMONSTRATION OF THE OPTICAL STERN-GERLACH EFFECT

We report the observation of the splitting of an atomic beam by the op tical Stern-Gerlach effect. A beam of metastable He atoms interacts wi th a nearly or exactly resonant laser field with a well-defined intens ity gradient perpendicular to the atomic beam. The coherent splitting of the atomic beam is produced in the case of exact resonance. For the nonresonant case, a deflection of the atomic beam is observed. We hav e studied the,splitting and deflection of the atomic beam as a functio n of laser detuning from resonance. Our results are in good agreement with theoretical predictions.