Subfemtosecond pulse generation with molecular coherence control in stimulated Raman scattering

We study the generation of subfemtosecond pulses with the molecular coheren ce control in stimulated Raman scattering. We show analytically that the an tiphased state temporally advances the higher frequencies with respect to t he lower frequencies during a beating cycle. After some propagation distanc e, due to the dispersion and the difference between the antiphased and phas ed states in advancing high or low frequencies, the coherence is highest on the negative side of the detuning, when the two-photon Rabi frequency is a bout equal to the detuning. This asymmetry of the coherence magnitude with respect to the negative and positive sides of the Raman detuning is reflect ed in the behavior of the tuning characteristics of the high-order frequenc y components. When the Raman detuning is small, although the process is non adiabatic, the subfemtosecond pulse generation may occur for both negative and positive sides of the detuning. [S1050-2947(99)00908-7].