Mapping of the Excited State Potential Energy Surface during Molecular Photo-isomerization to Control Chemical Reactions

We present a new perspective of light matter interaction with molecules. When using shaped pulses, we explain fundamentally how our understanding of absorption and dispersion changes. We show how the phase of the pulse can change an absorption line-shape to a dispersion-like line-shape. Contrary to conventional belief, we show that the first-order polarization is sensitive to the phase of the electric field. We show that by performing single pulse experiments that it is possible to "map" out the propagation of the wave packet in the excited state potential energy surface. In addition, we describe how to measure the momentum dependent lifetime of the wave packet through a conical intersection. We use these fundamental ideas to answer the question of finding an optimum coherent pulse(s) that will maximize the formation of a desired chemical species.