We present an experiment in which an ultrashort pulse train propagates resonantly through an optically dense vapor of atomic rubidium. The sequence obtained from a Fabry Perot interferometer comprises nearly 10 regularly time-delayed and mode-locked pulses. We show that a sequence with phase shift f =02 p between two successive pulses propagates with important temporal distortion, whereas a sequence with f = p 2 p experiences few propagation effects, thus leading for the first time to our knowledge to the possibility of phase control of dispersion effects for an ultrashort pulse train.
Voir en ligne : Opt. Lett. 28, 1272-74 (2003)