Two-photon resonance degenerate four-wave mixing in a three-level polar molecule (model calculations)

Abstract

The third-order non-linear susceptibility, χ(3)(ω; ω, ω, −ω), describing the phase conjugation by degenerate four-wave mixing (DFWM) is calculated for a three-level polar system under a two-photon resonance (TPR) condition. The part of the susceptibility expressed only by the transitional dipole moments and the part resulting from the permanent dipole moments are distinguished. The spectra of χ(3)(ω; ω, ω, −ω), as well as the DFWM power-reflection and power-transmission spectra near to the TPR, are modelled for polar molecules. The effect of enhanced reflectivity of TPR-DFWM is obtained numerically.