Ionization and dissociation of molecular ion beams caused by ultrashort intense laser pulses

Abstract

Studies of the simplest one-electron molecule, H2+, are the first step towards understanding the interaction of ultrashort intense laser pulses with molecules. We conduct coincidence 3D imaging measurements of H2+ beams following their exposure to intense ultrashort laser pulses. These measurements are compared with our time-dependent calculations as well as a simple model we recently proposed. Our findings include above threshold Coulomb explosion - a surprising structure in the energy spectrum near the ionization appearance intensity; above threshold dissociation (ATD) of the excited electronic states of H2+; and enhanced high-order ATD - involving the net absorption of at least 3 photons - brought about by closing the 2-photon channel. © 2007 IOP Publishing Ltd.