Abstract

The third-order nonlinear response function and optical susceptibility χ⁽³⁾ of polyatomic molecules and molecular aggregates in condensed phases are analyzed. Our expression for χ⁽³⁾, derived using Liouville space Green's function techniques, contains contributions from excitons as well as biexcitons. The scaling of χ⁽³⁾ with aggregate size and its dependence on the laser detuning and homogeneous and inhomogeneous dephasing rates are analyzed. Applications are made to phase conjugate degenerate four-wave mixing and pumpprobe spectroscopy.

© 1990 Optical Society of America