Abstract

Three-wave mixing in an isotropic medium is possible under the certain conditions /1/. Second-order susceptibility experiences great enhancement in both single- and two-photon resonances. On the other hand, one-photon resonance absorption imposes severe limitations on the density of nonlinear atoms. Coherent population trapping may reduce the absorption of the fundamental waves while still getting a resonantly enhanced nonlinear effect /2/. This phenomenon may be used to enhance the efficiency of the nonlinear generation by resonant frequency mixing /3/. In this paper we show how coherent population trapping influences the resonant nonlinear generation by mixing of two strong optical fields in an isotropic medium.

© 1996 IEEE