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, $\mid \Psi (R,t){\mid }^2$, and for the internuclear velocity, $\mid \Psi (v_R,t){\mid }^2$, of the wave packet are measured by ionization with a delayed, intense $20\mathrm{fs}$ nonresonant laser pulse. The pronounced interference pattern, observed in both $\mid \Psi \left(R\right){\mid }^2$ and $\mid \Psi \left(v_R\right){\mid }^2$, 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 $\mid \Psi \left(R\right){\mid }^2$ and $\mid \Psi \left(v_R\right){\mid }^2$ obtained by numerical wave packet propagation.

• Received 28 May 2004

DOI:https://doi.org/10.1103/PhysRevA.70.033404