Thickness-independent narrow resonance in a stack of two plasmonic lattices

TL;DR

This paper demonstrates a novel plasmonic mode in a stacked lattice structure that remains fixed at a Rayleigh anomaly regardless of inter-lattice spacing, simplifying fabrication of stable resonant devices.

Contribution

It introduces a thickness-independent narrow resonance mode in a stack of two plasmonic lattices, which is robust against variations in lattice spacing.

Findings

Mode positioned on Rayleigh anomaly remains fixed despite spacing changes

Resonance stability simplifies fabrication of plasmonic devices

Potential for designing more reliable plasmonic sensors

Abstract

Plasmonic lattices consisting of nanoparticles in a homogeneous environment are well known fortheir support of so-called lattice plasmon resonances. They are associated with localized surfaceplasmons coupled to each other via free propagating photons along the structure. In this paper, weexplore modes in a stack of two identical plasmonic lattices. We demonstrate that such a structureis able to support a mode that is positioned strictly on a Rayleigh anomaly and does not shift withthe variation of distance between two lattices in wide limits. Given the fact that period is the moststably reproduced quantity in an experiment, such behavior can be used to simplify the fabricationof structures with resonances at desired energies.