Wave Packet Structure and Dynamics Measured by Coulomb Explosion

The motion and dimension of molecular nuclear wave packets produced by an ultrashort laser pulse are measured by Coulomb explosion induced by a delayed intense fs laser pulse. Two different continuum wave packets in ${\mathrm{I}}_2$ are observed as they move from an internuclear separation of $\sim 7$ to $>100\mathrm{}$ Å. The ultimate spatial resolution is limited by the pulse duration of the probe laser. For 485 nm excitation of $B$-state wave packets the resolution limit is $\sim 0.5$ Å.