The absorption of a single photon by matter is well understood. But, how does our understanding of the underlying quantum effects, such as selection rules, extend if an atom or molecule absorbs more than one photon from an intense laser field?
While many effects in strong-field physics can be described using the single-active-electron approximation, energy transfer between electrons is mediated with electron correlation. We attempt to capture multielectron effects driven by short intense laser pulses.
It is nowadays possible to generate laser pulses at wavelengths spanning the whole regime from deep-ultraviolet to midinfrared wavelengths. Moreover, control over pulse duration, carrier envelope phase and polarization has been achieved. We explore the application of this laser light for fundamental processes such as ionization, high harmonic generation etc.
The quest for studying ultrafast dynamics in matter has driven the development of laser pulses with ultrashort pulse durations. Currently, the shortest pulses have duration of a few tens of attoseconds (1 as = 10-18 s). We study the application of such pulses to image electron dynamics in atoms and molecules.