Investigation of plasmon resonance of stacked gold nanodisks using time-domain simulations

Plasmon resonances are able to produce a large field enhancement, which can be exploited for various purposes, such as biosensing or optical mixing. In this paper, the plasmon resonance of two stacked gold nanodisks separated by a tiny 2 nm gap is studied in time-domain simulations, offering the possibility of transient and broadband analysis. Moreover, time-domain simulations are amenable to extensions towards nonlinear models. For efficient simulations, the extremely small gap in between the nanodisks, as well as potential fabrication imperfections, are advantageously modeled with an unstructured mesh. This paper presents 3D simulations of the nanodisk plasmon problem using the finite-volume time-domain method in a tetrahedral mesh.