Spectral Modification of Ultrashort Pulses Propagating through an Atomic Vapor

Extensive research has been performed on the temporal behavior of resonant short pulses propagating through an atomic vapor.1 In our studies, we have investigated experimentally and theoretically the modification of the spectrum of pulses propagating through an atomic vapor under conditions in which the pulse duration is much shorter than any of the relaxation times of the atomic system. We observe novel features in the spectrum of the transmitted pulse under conditions in which the area of the incident pulse is of the order of unity or greater.