Generation and detection of Rydberg wave packets by short laser pulses

We discuss the generation and detection of wave packets of Rydberg states by exciting electrons from a low-lying atomic state with a short pulse to a Rydberg series. To observe the motion of the wave packet, we analyze a time-delayed two-photon experiment, where the first laser pulse generates a wave packet, which is then probed by a second short pulse. The two-photon transition probability shows peaks when the time delay between the pulses is a multiple of the classical orbit time. A semiclassical formalism is developed to describe the motion of the wave packet and to analyze the time-delayed two-photon process.