O$_{2}^{+}$ dissociation caused by an ultrashort intense laser pulse*

Laser-induced dissociation of O$_{2}^{+}$ has been experimentally studied with ultrashort ($\sim $50 fs) intense (10$^{14}$ to 10$^{15}$ W/cm$^{2})$ laser pulses at 790 nm using kinematically complete coincidence 3D momentum imaging. The resulting kinetic energy release (KER) distribution has several distinct peaks, each of which has a unique angular distribution. The lower KER features are peaked around the laser polarization, while at higher KER, dissociation perpendicular to the laser polarization is significant. For comparison, a theoretical study of O$_{2}^{+}$ dissociation using the Electron-Nuclear Dynamics (END) approach with a laser pulse included in the time-dependent dynamics is underway. Preliminary results also indicate that ionization, which occurs predominantly at the high end of the intensity range, is strongly peaked along the laser polarization.