Control and imaging of interfering wave packets in dissociating I2 molecules

Dissociation of iodine molecules by two phase-locked 110 femtosecond laser pulses creates a wave packet in the repulsive part of the B state. The time-dependent density functions for the internuclear position, Ψ(R,t)2, and for the internuclear velocity, Ψ(vR,t)2, of the wave packet are measured by ionization with a delayed, intense 20 fs nonresonant laser pulse. The pronounced interference pattern, observed in both Ψ(R)2 and Ψ(vR)2, is controlled by the time separation of the two pump pulses. The experimentally determined internuclear position and velocity distributions are in very good agreement with calculated results for Ψ(R)2 and Ψ(vR)2 obtained by numerical wave packet propagation