Abstract
Contributions to the fifth-order nonlinear optical susceptibility of a collection of homogeneously broadened two-level atoms that scale as and , where is the lower-order atomic hyperpolarizability and is the atomic number density, are predicted theoretically. These “cascaded” contributions are a consequence of local-field effects. We determine them from a fifth-order solution of the Lorentz-Maxwell-Bloch equations. They are missing from a straightforward generalization of Bloembergen’s result for the local field correction to the second order nonlinearity, but are recovered by a careful application of his general approach. We find that at high atomic densities the value of the cascaded third-order contribution can be as large as the “direct” fifth-order term in the expression for the fifth-order susceptibility.
- Received 8 August 2007
DOI:https://doi.org/10.1103/PhysRevA.76.063806
©2007 American Physical Society