Strong Field Molecular Ionization with Shaped Ultrafast Laser Pulses

This work will advance our understanding of how electrons move in molecules. The motion of electrons in atoms, molecules and solids takes place on attosecond (a billionth of a billionth of a second) timescales, and requires very short laser pulses to resolve. The investigators in this project will use intense ultrashort laser pulses in order to ionize molecules, removing one of the many electrons bound to the molecule. They will take pictures of the electrons as they come off the molecules, making use of a technique called velocity map imaging. These pictures can be used to understand electron dynamics during ionization, which is important for molecular imaging, chemical dynamics and the development of new high speed electronics. This project will make use of shaped few cycle laser pulses to study strong field ionization of small molecules. The investigators will make use of ultrafast optical pulse shaping of filament based sub 10 fs (3-4 optical cycles) laser pulses, as well as velocity map imaging in order to study the angle and momentum resolved photoelectron spectrum as a function of laser pulse shape. This will help develop our understanding of how electrons are removed from multiple orbitals, and the extent to which electron correlation and non-Born Oppenheimer dynamics play a role in the ionization dynamics. The investigators will also make use of strong field ionization as a probe of excited state dynamics, studying dissociation and internal conversion in families of similar molecules.