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. [Display omitted] •Optical properties of square arrays of gold nanodiscs with varying diameters are compared for different substrates.•Micro-ellipsometry is employed to probe the systems. The spectral features are assigned to corresponding resonances.•Comparison of different techniques shows that the spectral peaks do not necessarily coincide with the resonance wavelengths.•The influence of surface plasmons is clearly observed in the spectra of the metal-insulator-metal structures.