Light scattering from coupled plasmonic nanospheres on a substrate

TL;DR

This paper presents a numerical method to analyze light scattering from coupled plasmonic nanospheres on substrates, enabling better interpretation of experimental ellipsometric spectra for nanosphere distributions.

Contribution

The study introduces an efficient computational approach using Green functions and spherical harmonics to model plasmonic coupling effects in nanosphere clusters on substrates.

Findings

Accurately fits experimental ellipsometric spectra with few parameters.

Demonstrates the method's capability to determine nanosphere distributions.

Shows potential for analyzing biological samples with embedded nanospheres.

Abstract

An efficient numerical method based on half-space Green function and spherical harmonics expansion is used to study the light scattering from coupled multiple nanospheres on a substrate. The ellipsometric spectra for various geometries of coupled Au nanospheres are calculated and analyzed to realize the effects of plasmonic coupling of closely-spaced nanospheres. With only a few parameters to describe the distribution of various coupled nanosphere clusters embedded in a random distribution of nanospheres, the calculated ellipsometric spectra can fit the experimental data very well. This illustrates that our realistic model calculations can be used for determination of the distribution of nanospheres on a substrate or embedded in multilayer structures such as biological samples.