Light scattering from coupled plasmonic nanospheres on a substrate

摘要

An efficient numerical method based on half-space Green function andspherical harmonics expansion is used to study the light scattering fromcoupled multiple nanospheres on a substrate. The ellipsometric spectra forvarious geometries of coupled Au nanospheres are calculated and analyzed torealize the effects of plasmonic coupling of closely-spaced nanospheres. Withonly a few parameters to describe the distribution of various couplednanosphere clusters embedded in a random distribution of nanospheres, thecalculated ellipsometric spectra can fit the experimental data very well. Thisillustrates that our realistic model calculations can be used for determinationof the distribution of nanospheres on a substrate or embedded in multilayerstructures such as biological samples.