Abstract

A new scheme for coherently pumping two-photon transitions is demonstrated theoretically-It is shown that a total inversion can be achieved by using a pair of bichromatic ultrashort pulses tuned close to an intermediate resonance. The proximity of the intermediate resonance greatly enhances the efficiency of the process, making it possible to reach total inversion with energy densities of the order of microjoules per square centimeter. At the same time, the resonance conditions are controlled in such a way that at no time a dipole moment is created (the off-diagonal elements corresponding to dipole transitions remain <0.1).

© 1995 Optical Society of America