Enhancement of Optical Nonlinearity Through Anisotropic Microstructures

TL;DR

This paper explores how the polarization direction affects the enhancement of optical nonlinearity in anisotropic metal nanocrystal composites, revealing significant polarization-dependent differences in nonlinear response.

Contribution

It provides a detailed analysis of polarization effects on optical nonlinearity enhancement in uniaxial anisotropic composites, highlighting differences between parallel and perpendicular polarizations.

Findings

Enhancement factor increases with anisotropy for perpendicular polarization.

Parallel polarization results are similar to previous 2D studies.

Strong polarization dependence observed in nonlinear optical response.

Abstract

We investigate the polarization dependence of optical nonlinearity enhancement for a uniaxial anisotropic composite of metal nanocrystals in a dielectric host. Three cases are distinguished depending on whether the polarization is parallel, perpendicular or unpolarized with respect to the axis of anisotropy. For the parallel polarization, the results show that the 3D results are qualitatively similar to the 2D case reported recently. For the perpendicular polarization, the results are markedly different from the parallel counterpart: In contrast to the absorption, the enhancement factor actually increases with the anisotropy. Thus the separation of the absorption and enhancement peaks becomes even more pronounced than the parallel polarization case. These results indicate a strong polarization dependence of the nonlinear optical response.