Oscillatory optical response of amorphous plasmonic nanoparticle arrays

The optical response of metallic nanoparticle arrays is dominated by localized surface plasmon excitations and is the sum of individual particle contributions modified by inter-particle coupling depending on specific array geometry. Here we scrutinize how experimentally measured properties of large scale (30 mm$^{2}$) amorphous Au nanodisk arrays stem from single particle properties and their interaction. They give rise to a distinct oscillatory behavior of the plasmon peak position, full-width at half-maximum, and extinction efficiency which depends on the minimum particle center-to-center (CC) distance.