Abstract: The kinetic energy and angular distributions of H+ as a function of 405 nm femtosecond laser intensity are experimentally measured by using velocity map imaging technique. The reaction pathways of dissociation channels, and , are discussed. The former is due to the direct one-photon pathway via the crossing, and the latter stems from Coulomb explosion of . Ionization of to starts from bond softening. The relative yield of fragment peaks indicates that dissociation and ionization of are competitive. The lower laser intensities emphasize the dissociation of , and the higher laser intensities favor the ionization of .

Key words: quantum optics; reaction pathways; velocity map imaging; light-dressed states