GENERATION OF TRANSIENT RABI SIDE-BAND IN PULSE-PROPAGATION - A POSSIBLE SOURCE FOR CONE EMISSION

We study the one-dimensional propagation of a laser pulse through an a tomic vapor of finite length L. Both the temporal and the time-depende nt spectral profiles of the exiting laser pulse are calculated. It is shown that, when the pulse duration is comparable with or shorter than the effective relaxation time of the atomic density matrix, the spect rum of the final pulse exhibits frequency sidebands located in the vic inity of the time-varying generalized Rabi frequency, which can contai n up to a few percent of the total laser power. The possible connectio n between this result and cone emission in the pulsed regime is addres sed.