Enhanced optical properties of metal-coated nanoparticles

TLDR

The study provides general expressions for local‑field enhancement, absorption, and nonlinear optical response of metal‑coated nanoparticles within effective medium theory for small volume fractions. The authors model metal‑coated nanoparticles with realistic coating‑thickness distributions, use heuristic arguments to assess diffuse interface effects, and employ an efficient solution method adaptable to any number of coatings.

Abstract

Metal-coated, nanometer-size particles are modeled with a realistic distribution of coating thicknesses. General expressions are given for the local-field enhancement, absorption, and nonlinear optical response. In addition, heuristic arguments are used to determine the effects of a diffuse, rather than a sharp interface. The linear and nonlinear optical properties are discussed within the context of the effective medium theory for small volume fractions. An efficient method of solution is used with the flexibility to handle an arbitrary number of coatings.