Events Archive

Institutsseminar

Title

Institutsseminar

Description

Photoionization with Shaped Femtosecond Laser Pulses

Prof. Dr. Matthias Wollenhaupt
University of Oldenburg

Abstract:

In this talk, we demonstrate the manipulation of the 3D photoelectron momentum distribution (3D PMD) by multiphoton ionization (MPI) of atoms with polarization-shaped femtosecond laser pulses. After introducing the physical mechanisms of the coherent control of MPI, we present recent photoelectron tomography measurements from perturbative and non-perturbative MPI. Experimental results on the generation and manipulation of free-electron vortices with single-color and bichromatic polarization-shaped pulses will be presented, together with a novel Fourier-based analysis technique to extract the quantum mechanical phase of the 3D PMD. The latter provides insights into the underlying dynamics of the MPI. In addition, we present the first experimental demonstration of shaped electron vortices (SEVs), created by perturbative and non-perturbative atomic MPI with oppositely chirped, counterrotating circularly polarized (CRCP) pulses and study the absorption delay in (1+2) resonance-enhanced MPI using transform limited CRCP pulse sequences. Finally, we investigate and control ultrafast spin-orbit wave packet dynamics in the potassium 4p fine-structure doublet using bichromatic pump-probe sequences.

Location

Seminarraum HI-Jena, Fröbelstieg 3

Date

14.11.2024