Probing the ultrafast nuclear motion in CS2 2+ in intense laser fields.

The temporal evolution of the nuclear wave packet of CS2 2+ formed in an intense laser field (60 fs, 0.13 PW/cm2) is traced in real time by the pump-and-probe technique combined with coincidence momentum imaging of the Coulomb explosion process, CS2 3+-->S+ + C+ + S+. The momentum correlations among the fragment ions obtained as a function of the pump-probe time delay between 133 fs to 3 ps reveal that the nuclear wave packet in CS2 2+ evolves not only along the anti-symmetric stretching coordinate to yield S+ and CS+ but also along the symmetric stretching coordinate leading to the simultaneous breaking of the two C-S bonds. The contribution from two different electronic states having bent and linear-type geometrical configurations is identified in the wave packet motion along the bending coordinate of CS2 2+.