Exceptional compound plasmon-polariton waves

TL;DR

This paper investigates exceptional compound plasmon-polariton waves in a tri-layer structure with anisotropic dielectric, revealing unique decay behavior and providing numerical solutions for specific configurations.

Contribution

It introduces the concept of exceptional CPP waves in anisotropic structures and analyzes their properties and field profiles through numerical solutions.

Findings

Exceptional CPP waves exhibit non-exponential decay on the anisotropic side.

Numerical solutions for uniaxial-dielectric/metal/isotropic-dielectric structures are provided.

The structure supports unique propagation modes due to anisotropy.

Abstract

Ordinarily, a trimaterial structure comprising a sufficiently thin metal film interposed between two homogeneous dielectric materials guides compound plasmon-polariton (CPP) waves, for which the fields on both sides of the metal film decay exponentially with distance from the nearest metal/dielectric interface. However, if one of the dielectric materials is anisotropic then the trimaterial structure can guide an exceptional CPP wave for a particular propagation direction. On the side of the metal film occupied by the anisotropic dielectric material, the fields of the exceptional CPP wave decay as the product of a linear function and an exponential function of the distance from the nearest metal/dielectric interface. The canonical boundary-value problem for CPP-wave propagation has been analyzed and solved numerically; thereby, the spatial field profiles for exceptional CPP waves for a uniaxial-dielectric/metal/isotropic-dielectric structure have been established.