Extraordinary Transmission in Coupled Nano-Bridged Nanosphere Quasi-Complimentary Arrays

Ultra-sensitive structures can be based on percolation, which at the threshold radically change their response (e.g. conduction, transmission, etc.). However, due to the critical nature, such structures are very unstable at the threshold. Here, we demonstrate that the stability can be restored, with minimal loss of sensitivity, by engineering weak links between the units of a percolation system. Our system consists of a pair of strongly coupled complementary arrays made of metallic films, obtained by depositing plasmonic metal on a periodic array of spheres with submicron dimensions through a modified standard nanosphere lithography (NSL). In an earlier work we demonstrated, that the modification of NSL leads to the formation inter-sphere nano-bridges, which after metallic deposition work as the weak links. We simulate plasmonics of these arrays, demonstrating ultrahigh sensitivity and stability of the extraordinary optical transmission (EOT) of this structure near the percolation threshold.