CH3ONO PREDISSOCIATION BY ULTRASHORT LASER-PULSES - POPULATION TRANSIENTS AND PRODUCT STATE DISTRIBUTION

We use a two-dimensional potential energy surface for CH3 ONO to model the behavior of the molecule interacting with an ultrashort laser pulse. All the results presented here are obtained by solving accurately the time-dependent Schrödinger equation; when possible we also develop a simple model to explain the exact observations. We calculate the lifetimes of the predissociative resonances, the transient populations induced by semi-infinite pulses, and the time evolution of the product state distribution after excitation with a very short pulse. The behavior of the excited state population created by the pulse is explained in terms of the interference between the amplitudes representing photon absorption at different times when the pulse-molecule interaction is not zero. The time evolution of the final state distribution is explained in terms of interference between the wave packets at different times from the interaction region. © 1990 American Institute of Physics.