Enhanced and controllable nonlinear effects in composite with aligned gold spheroid arrays

Abstract

The linear and nonlinear optical properties of composite containing aligned prolate spheroid nanoparticles embedded in a dielectric host are studied as a function of depolarization factor. It is shown that the effective third-order nonlinear susceptibility of the composite can be significantly enhanced with respect to the linear optical properties, due to a combination of varying nanoparticle shape and interparticle space. The susceptibility enhancement is up to four orders larger compared to the spherical case. The susceptibility enhancement of the host is finally comparable to the inclusion after choosing property structure parameters. The geometry-dependent susceptibility enhancement can lead to an improved figure of merit for nonlinear absorption.