| Novel electronic wavepackets have been created and probed through multistep laser excitations and electric field pulse interactions. Three experiments are presented here, each of which uses a half cycle pulse of THz radiation (HCP) as a tool for manipulating wavepacket dynamics. In the first experiment, a HCP field recombines a continuum electron with a nearby ion in the presence of a static field. The relative alignment of the HCP and the static field turns out to be a crucial factor in determining recombination rates. In a second experiment, a HCP influences the rate of autoionization (AI) in a doubly excited Rydberg state. Some suppression of the AI rate is observed due to HCP redistribution of the Rydberg population. In the final experiment, the time dependent momentum space probability distribution of a recombined electronic wavepacket is measured by observing the response of the recombined wavepacket to a HCP field. A highly localized three dimensional electronic wavefunction is created through the recombination process and the dynamics of this distribution are measured. A new technique of lock-in impulse momentum retrieval (IMR) is developed to improve signal to noise in the recovered momentum distribution. Both classical and quantum mechanical simulations are performed which reproduce measured spectra. |
