Strong Fields


Time proved that the somewhat counterintuitive statement of the photoelectric effect theory where the energy of an emitted electron isn’t dependent on the incident light intensity is not the whole truth. Upon increasing light intensity nonlinear effects come into play. Nowadays we are comfortable with the existence of multiphoton ionization (MPI) processes in the lab, which become observable only after the invention of the laser. If the laser light intensity is further increased, the nonlinearity of the light-matter interaction grows and new effects show up. When the intensity of the electric field becomes strong enough to distort the core potential of an atom (field strength in H atom ~1011 V/m corresponds to the light intensity ~1016 W/cm2), ionization can occur by tunneling through the potential barrier.

Atoms in Strong Fields

Molecules in Strong Fields

Non-Adiabatic Multi-Electron Dynamics

Dynamic Polarization

High Harmonic Generation and Molecules