Micro-ellipsometry of square lattices of plasmonic nanodiscs on dielectric substrates and in metal-insulator-metal configurations

This article demonstrates the capability of imaging micro-ellipsometry in the investigation of ordered plasmonic nanostructures on different substrates. The difference of the resonances of similar square lattices of plasmonic nanoparticles on a dielectric substrate and in a metal-insulator-metal configuration is analyzed. The influence of the surface plasmon on interparticle interactions becomes clearly apparent. Comparison of the obtained data with dark-field scattering spectra proves the consistency of the measured results as well as the complementary information received from both methods.