General Physics Colloquium

'Resolving and manipulating attosecond processes via strong-field light-matter interactions'

Nirit Dudovich

Weizmann Institute of Science, Rehovot

The interaction of intense light with atoms or molecules can lead to the generation of extreme ultraviolet (XUV) pulses and energetic electron pulses of attosecond (10^-18) duration. The advent of attosecond technology opens up new fields of time-resolved studies in which transient electronic dynamics can be studied with a temporal resolution that was previously unattainable.

I will review the main challenges and goals in the field of attosecond science. As an example, I will focus on a recent experiment where the dynamics of tunnel ionization – one of the most fundamental strong-field phenomena – were studied. Specifically, we were able to measure the times when different electron trajectories exit from under the tunneling barrier created by a laser field and the atomic binding potential. In the following stage, subtle delays in ionization times from two orbitals in a molecular system were resolved. This experiment provides an additional, important step towards achieving the ability to resolve multielectron phenomena -- a long-term goal of attosecond studies.

In the next part of my talk I will describe how we can proceed directly from measurement to control. In this study we link the generation process of attosecond pulses to the field of caustics - a unique type of singularity that is common to all wave phenomena. We demonstrated that caustics can appear in attosecond processes and showed that they offer a deeper understanding of the basic mechanism.

Coffee/tea and cake will be served at 3 PM.