RADIATIVE RENORMALIZATION ANALYSIS OF 2-LEVEL SYSTEMS WITH PERMANENT DIPOLE-MOMENTS

The radiative renormalization technique is used to analyze two-level s ystems with permanent dipole moments under the influence of a single-f requency applied field. The advantage of radiative renormalization ove r the usual perturbative or harmonic balance techniques lies in the co mputational ease with which the density matrix operators can be determ ined to any order in applied field. We characterize the absorption and dispersion of a typical two-level system within this framework and fi nd that although the absorption saturates as expected with increasing incident field strength, additional oscillatory behavior is evident at extremely high field strengths. The structure and period of these osc illations is dependent upon the magnitude of the permanent dipole mome nt. Our general formalism can easily be extended to the study of other nonlinear optical phenomena.