Asymmetric dissociation of H2 and D2 by a two-color laser field

Two-color (800 nm and 400 nm) short (45 fs) linearly polarized pulses are used to ionize and dissociate H2(D2) into a neutral hydrogen (deuterium) atom and a proton(deuteron). The yields and energies of the ions are measured left and right along the polarization vector. As the relative phase of the two colors is varied, strong yield asymmetries are found in the ion energy regions corresponding to bond softening, above-threshold dissociation and rescattering. A model based on the dynamic coupling by the laser field of the gerade and ungerade states in the molecular ion accounts for many of the observed features.