Observation of a strong rectified dipole force in a bichromatic standing light wave

Abstract

We report on the observation of a strong optical dipole force which is exerted on atoms in a bichromatic standing light wave as a result of nonlinear wave-mixing processes. This force can substantially exceed the upper limit of the spontaneous light force and, in contrast to the dipole force in monochromatic standing-wave fields, acts with constant sign on a macroscopic spatial scale.