Utilizing the plasmonic resonance to enhance three wave mixing effects in nano-scale cut-wire

Abstract

In this paper, quantitative study of the enhanced three wave mixing effects from periodic array of nano-scale golden cut-wires embedded in nonlinear dielectric is performed. Geometrical parameters of the considered structure are chosen so that the plasmonic resonance occurs in the wavelength 1.5 μm. Plasmonic resonance of this structure gives rise to the localization factor significantly larger than that of the cut-wire structures with no plasmonic resonance. Considering the surrounding medium of the cut-wire a typical second-order nonlinear optical medium, enhancement of the nonlinearity of this nonlinear medium is illustrated. Since the mentioned structure can be considered a homogeneous nonlinear medium with the effective nonlinear susceptibility, nonlinear retrieval method is used to determine the effective nonlinear susceptibility for all four frequency combinations. Maximum enhancement of the effective susceptibility is obtained for the second harmonic generation of the applied wave with the frequency corresponding to the plasmonic resonance, with the enhancement up to two orders of magnitude. Efficiency of the second harmonic generation in this resonant structure surrounded with nonlinear dielectric is calculated to be 30 times more than that of the nonlinear dielectric with the same dimensions.