Direct eigenmode analysis of plasmonic modes in metal nanoparticle chain with layered medium

Abstract

Using the dyadic Green function (GF) with a multilayer medium, we propose an eigendecomposition (ED) analysis of a plasmonic system composed of a one-dimensional periodic metal nanoparticle chain and planar layered structure. An effective eigenpolarizability involving the collective effects of both the chain and the layered structure is well defined to characterize the dispersion relation and the mode quality of the plasmonic modes. Applying this method, we demonstrate that the interplay between the surface plasmon polaritons (SPPs) at the metal-dielectric interface and the localized plasmon in the chain enables strong mode splitting. In particular, for the polarization perpendicular to layer surface, high-quality modes can be present inside the light cone even if the chain is open to the surrounding air. A slow-light band is also predicted to exist as long as the layered medium supports a SPP mode that can couple to the chain mode.

Engineering plasmon dispersion relations: hybrid nanoparticle chain -substrate plasmon polaritons

“…In contrast to previous work, in which only one particular metal substrate has been studied [39], we show that the plasma frequency of the metal substrate plays a dominant role in determining the optical properties of this compound system. Choosing the appropriate plasma frequency, i.e., by selecting a specific substrate, the hybrid polaritons in this system can have very high, almost zero, or even negative group velocities.…”

“…(3) reduces the system to three equations, one for each component of the polarization. For an infinite chain in the geometry under consideration, this results in [39] 1…”

“…Understanding and exploiting the full functionality of these compound devices requires a deep understanding of how these two modes interact with each other. The coupling between both types of SPPs has been studied recently by several groups, considering linear chains [39,40] and two dimensional nanoparticle arrays [41,42] above metal substrates. These system were investigated both experimentally [42] and theoretically [39,40,42].…”

“…The coupling between both types of SPPs has been studied recently by several groups, considering linear chains [39,40] and two dimensional nanoparticle arrays [41,42] above metal substrates. These system were investigated both experimentally [42] and theoretically [39,40,42]. It has been shown that the coupling between the chain and substrate plasmon modes is strong, and that the dispersive properties of hybrid modes can be significantly different from the individual, uncoupled modes.…”

Complex-k modes of plasmonic chain waveguides

“…Plasmonic chain waveguide in its simple setting has been studied mostly through theoretical modeling [1,[6][7][8][9][10][11][12][13] and, in fewer occasions, through experiments [14][15][16][17][18][19][20][21]. There are several ways to prepare chain waveguides.…”