Vibrationally-resolved structure in O$_{2}^{+}$ dissociation by intense ultrashort laser pulses

Laser induced dissociation of O$_{2}^{+}$ is studied in the strong-field limit using a crossed laser--ion beam coincidence 3D momentum imaging method (790 and 395 nm, 40 fs, $\sim $10$^{15}$ W/cm$^{2})$. The measured kinetic energy release spectra from dissociation of O$_{2}^{+}$ reveal vibrational structure never observed before in multielectron molecules, which persists over a wide range of laser intensities. By evaluation of the potential energy curves, we assign the spectral energy peaks to dissociation via a one photon pathway $\vert ^{ }$a$^{ 4 }\Pi _{u }> \quad \to \quad \vert ^{ }$f$_{ }^{4 }\Pi _{g }-_{ }$1$\omega _{ }>$ --- a bond softening mechanism similar to the one observed in H$_{2}^{+}$. Careful inspection unveils an apparent suppression in the dissociation of particular vibrational peaks which is a manifestation of the well-known Cooper minima effect.