Control strategies for reactive processes involving vibrationally hot product states

Abstract

We present an all optical control mechanism for the switching process in fulgides via electronically excited states in the presence of conical intersections. The underlying photoreaction is the ring opening or closure of the central C 6-ring chromophore. The control of this reaction is realized with shaped laser pulses which are obtained by Optimal Control Theory. Our implementation of the algorithm enables the definition of a target in the electronic ground state even if vibrationally hot product states are formed during the reaction demanding the appliance of a damping function. We introduce a flexible target definition including all parts of the wavepacket that will reach the target region within a given time interval T. Thereby the localization of the wavepacket inside this region at a specific point in time is not mandatory. A target definition in the ground state facilitates the comparability to experiments. With this target, the control algorithm favors an all optical process which is faster than the relaxation through the conical intersections. To enhance the possibility of experimental realizations, we analyze the optimized pump–dump sequence to allow a reconstruction and simplification of the laser field.