Temporal coherent control of an excited state wave packet is produced by a sequence of two identical ultrashort laser pulses. We show theoretically and experimentally in the case of the $(6s-7d)$ two-photon transition in Cs that optical and quantum interferences take place and are clearly distinguished.

• Received 31 October 1996

DOI:https://doi.org/10.1103/PhysRevLett.78.2716