Abstract

The exceptional time resolution obtained with femtosecond laser systems is one necessary ingredient to observe molecular dynamics in real time. Well defined initial states and well defined final states are crucial in order to follow for example the reaction pathway in a pump probe experiment in detail. Vibrationally and rotationally cold inital states are often prepared in a supersonic molecular beam. The ionic ground state is stable and unperturbed and therefore suitable as final state: the kinetic photoelectron distribution resulting from direct ionisation into the ionic ground state depends on the Frank-Condon factors and is therefore highly sensitive to follow the intermediate dynamics (change in Frank-Condon factors) in a pump probe experiment. Here we report on first femtosecond pump-probe experiments using this combination of technologies.

© 1996 IEEE