FEMTOSECOND REAL-TIME PROBING OF REACTIONS .16. DISSOCIATION WITH INTENSE PULSES

In this contribution, we consider the wave packet dynamics in the diss ociation reaction of NaI at different laser powers for both the prepar ation and the probing. The probing is made for the asymptotic Na fragm ent as well as the transition-state complex [Na...I]double dagger. A novel nonlinear behavior at higher intensities is reported and examine d here with a new set of experiments. This behavior reflects the chang e in the absorption cross section along the reaction coordinate and ca n be quantified using a simple kinetic picture and a classical model o f the dynamics.