Nonperturbative Analysis of Optical Double Resonance with Application to Phase Conjugation

Abstract

Optical double resonance has been extensively studied 1–7 in the context of high-resolution spectroscopy. More recently, its use has been suggested for optical bistability8, 9 and phase conjugation. 10, 11 A theoretical description of these nonlinear phenomena requires the knowledge of the response of a three-level system interacting with two resonant fields. Since optical saturation plays an important role, a nonperturbative solution of the corresponding density-matrix equations is required. In its most general form that includes Doppler broadening, arbitrary level detunings, and arbitrary relaxation rates, such a task can be accomplished only numerically. Useful analytical expressions for the nonlinear susceptibility can, however, be obtained under various simplifying assumptions.