Light scattering from coupled plasmonic nanospheres on a substrate

摘要

An efficient numerical method based on half-space Green's 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 nano- sphere 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 determi- nation of the distribution of nanospheres on a substrate or embedded in multilayer structures, such as biological samples.