Wave packet phenomena in Rydberg atoms represent the scope of the present work. In the centre of interest are on the one hand the suppression of dispersion of radial Rydberg wave packets in two-electron atoms and on the other hand the laser excitation of angular Rydberg wave packets in one-electron atoms. Radial Rydberg wave packets in two-electron atoms can be stabilized against dispersion by applying a suitable laser field which induces Rabi oscillations of the atomic core. This procedure gives rise to slowly decaying but nondispersing radial Rydberg wave packets. Calcium serves as a realistic model for a quantitative investigation of this stabilization effect. The investigation focusses on the spontaneous emission of the core. It shows that stabilized wave packets with low mean principle quantum numbers are practically unaffected by spontaneous decay. In the case of highly excited wave packets, however, the stabilization effect is impaired by the spontaneous emission of the core. Therefore an extension of the original system is proposed and investigated. It rests upon the application of two laser fields driving the core in lambda configuration and thereby inducing Rabi-like oscillations between a stable and a metastable state of the core. In this extended system nondispersing radial Rydberg wave packets can be observed, which are practically unaffected by spontaneous decay. Furthermore, the question is addressed whether an angular Rydberg wave packet can be excited in a one-electron atom by a single laser pulse with suitable frequency, intensity and duration. Hydrogen is used as a realistic model for thorough calculations within the dipole approximation, which is a very rough but for technical reasons inevitable approximation in the present system. The calculations do not indicate any mixing of angular momentum quantum numbers in the case of moderate laser intensities. Therefore an extended excitation scheme, which consists of the application of two consecutive laser pulses, is proposed and investigated. The first laser pulse excites a radial Rydberg wave packet. The second laser pulse possesses a frequency, which is sufficiently small to induce Raman-like transitions between the Rydberg states even in the case of moderate laser intensities. In this system, the performed calculations within the dipole approximation are completely valid and show mixing of the angular momentum quantum numbers due to the Raman-like transitions. Radial-angular Rydberg wave packets are excited.
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