Professor Shaul Mukamel is supported by a grant from The Theoretical and Computational Chemistry Program to develop theories which help us to understand nonlinear optical properties of gas phase clusters, solutions, and molecular crystals. A further understanding of nonlinear optical properties is very important in the development of new laser optical spectroscopic materials and techniques. The research is focused on the development and application of a dynamical description of molecular radiative processes using density matrix techniques in Liouville space. This technique permits the direct calculation of thermally averaged observables. Theoretical models are being constructed for the third order nonlinear response function which describes a broad range of four wave mixing and related spectroscopies. Applications are being made to femtosecond pump-probe spectroscopy in supersonic beams and in condensed phases, dielectric fluctuations in polar solvents, superexchange in electron transfer processes, radiative decay processes in molecular clusters, and exciton transport and retardation effects in molecular crystals.
