Influence of phase modulation on the reshaping of ultrashort laser pulses in resonant three-level systems - art. no. 043808

We present a detailed study of the interaction of ultrashort laser pulses w ith a resonant three level system (fine structure levels of rubidium). As e xpected, for low intensities a linear model and for higher intensities a se miclassical model (Maxwell-Bloch) is fully sufficient to describe the obser ved results. In both cases, however. it is essential to have an accurate kn owledge of the incident electric field. i.e., the amplitude and the phase, in order to simulate the interaction process. It is shown that on small tim e scales the phase modulation of the incident pulse influences the reshapin g process during pulse propagation whereas on longer time scales the reshap ing is solely governed by the dynamics of the atomic system.