Size-effects on Optical Properties of Asymmetric Plasmonic Nanodisk Trimer

摘要

We present the size and configuration effects on optical properties of an asymmetric nanodisk (Ag) trimer based on dipole interaction model and numerical calculations. The structure made of three Ag nanodisks of the diameter D = 100 nm and thickness T = 25 nm. Opposite to the symmetric structure composed of such nanodisks the asymmetric structure has a new mode in its optical extinction spectrum occurring between the two modes described for the symmetric structure. The properties of this new mode remarkably affects by the size and also by the asymmetric configuration of the structure. We apply theoretical analysis of coupled dipole approximation (CDA) to compare the symmetric and asymmetric optical properties of such structure. The results of theoretical method compared with the numerical simulations.