Effects of orbital symmetries on the ionization rates of aligned molecules by short intense laser pulses

Abstract

It is shown that by measuring the angular distributions of fragmented ions of simple molecules by sub-10 fs laser pulses at intensities in the non-sequential double ionization regime the electron density of the highest occupied molecular orbital can be probed directly. For pulses of a few tens of femtoseconds or longer, it is shown that the angular distributions of the ions are dominated by post-ionization alignment which results from the additional rotation of the molecular axis during the breakup process. These models are used to explain recent experiments.