Stimulated Raman scattering with slow light

Abstract

Summary form only given. We show that, even in a far-off-resonance Raman system driven by a strong coupling field, the combination of a high density and a small coherence decay results in a steep dispersion in the vicinity of two-photon resonance and, consequently, allows us to slow down the speed of light pulses and to produce an efficient nonlinear conversion. We show analytically that the interaction of a far-off-resonance Raman medium with a strong field, under the conditions of high density, narrow Raman-transition width, and small two-photon detuning, results in a slow group velocity and a substantial enhancement of an injected anti-Stokes field as well as an efficient generation of a Stokes sideband field. We find that the group velocity V is the same for the two sideband fields. Unlike the case where a single sideband is considered, the quantity 1/V/spl middot/1/c is proportional to the sideband frequency difference instead of the field frequency. This difference is due to the fact that the contributions from the two sideband fields to the two-photon phase shift have opposite signs while their magnitudes are proportional to their frequencies. We also discuss the condition for exponential growth of the two sideband fields in the medium. This condition requires the dispersion of the medium, the intensity of the strong coupling field, and the two-photon detuning to be in an appropriate range.