Optimizing frequency dispersed transient absorption signals: A computational study

Laser pulse control of molecular dynamics is studied theoretically by focusing on optical excitation and wave packet formation via a direct optimization of the probe pulse absorption in a pump-probe scheme. By extending earlier studies [A. Kaiser, V. May, J. Chem. Phys. 121 (2004) 2528], here, the absorbance of the probe pulse is maximized in a particular frequency window. In this way one may selectively enforce either stimulated emission or excited state absorption. By applying Optimal Control Theory the concept is demonstrated for a prototypical molecular three level system, whereby a flexible technique is suggested to form particular wave packets in a larger region of the excited state potential energy surface.