Characterization Of Light-Induced Potentials In The Strong-Field Dissociation Of O-2+

We investigate theoretically the imprints of light-induced potentials (LIPs) on the dissociation dynamics of O-2+ molecular ions, as observable in angle-resolved fragment kinetic-energy-release (KER) spectra. Following the vibrational and rotational dynamics of the initial pump-laser-excited cationic nuclear wave packet, while accounting for the dipole coupling between the O-2+ (a(4)Pi(u)) and O-2+ (f(4)Pi(g)) electronic states in 800-nm 40-fs probe-laser pulses with peak intensities between 10(13) and 10(14) W/cm(2), we calculate angle-resolved KER spectra which reveal characteristic energy- and angle-dependent fringe structures. These fringes shift downward in energy as the molecular alignment angle theta relative to the probe-pulse polarization direction increases from 0 to pi/2. The angle-dependent shifts in the KER fringes increase for larger probe-pulse peak intensities and follow the angle and light-wave-intensity dependence of the vibrational spectrum in the associated Floquet bond-hardening well, which is a manifestation of transient O-2+ nuclear-probability trapping in the LIP during dissociation. By examining the rovibrational dynamics of the dissociating molecular cation near the light-induced conical intersection (LICI) in the cationic LIP surface at theta = pi/2, we identify related angle-dependent structures in the KER spectra, suggesting a means for assessing the significance of LICIs in molecular dissociation pathways.