New strategy for optimal control of femtosecond pump-dump processes

We propose a new strategy for optimal control with tailored pump-dump pulses which drive a system of moderate complexity via electronically excited states to a desired objective in the ground state with a maximal yield. It is based on the concept of the intermediate target in the excited state which selects the appropriate Franck-Condon window at a given time delay between the two pulses mandatory for reaching optimally the objective.. The existence of the intermediate target ensures the connective pathway between the initial state and the objective in the ground state, necessary for the controllability of multidimensional systems involving two electronic states. We show the scope of this concept by optimizing and analyzing the pump and dump pulses for driving the isomerization process in the Na3F2 cluster to the second isomer by suppressing radiationless transition through the conical intersection between the first excited and the ground state. This has been realized by employing our ab initio Wigner distribution approach.