Abstract

There has been considerable interest in the force experienced by a three-level atom interacting with a nultichromatic optical field.^1–4 Several theoretical results have emerged, each of which emphasizes different aspects of the interaction. The three-level Λ system (see Fig. 1) has been of particular interest. In this case the force has beet) discussed in terms of the nonlinear mixing of the fields,¹ in terms of the role of the dark or transparent superposition ground state,⁴ and in terms of a combination of optical pumping and light shifts. In each of these treatments an important result has been the prediction of a long- wavelength, or rectified, force. This is a force component that is periodic over the beat wavelength of the bichromatic field, a length that for many atoms can be of the order of centimeters.

© 1993 Optical Society of America