Electromagnetic Green's function for layered systems: Applications to nanohole interactions in thin metal films

TL;DR

This paper derives a Green's function for layered electromagnetic systems, enabling analysis of plasmonic interactions in nanostructures, demonstrated through nanohole scattering in thin metal films.

Contribution

It introduces a transfer matrix-based method to compute the Green's function for layered media, revealing symmetry and long-range properties relevant to plasmonic phenomena.

Findings

Nanohole interactions are significantly mediated by surface plasmons.

The Green's function approach captures boundary and plasmon wave effects.

Application to nanohole chains shows enhanced scattering due to plasmon coupling.

Abstract

We derive expressions for the electromagnetic Green's function for a layered system using a transfer matrix technique. The expressions we arrive at makes it possible to study symmetry properties of the Green's function, such as reciprocity symmetry, and the long-range properties of the Green's function which involves plasmon waves as well as boundary waves, also known as Norton waves. We apply the method by calculating the light scattering cross section off a chain of nanoholes in a thin Au film. The results highlight the importance of nanohole interactions mediated by surface plasmon propagating along the chain of holes.