Dyakonov-Voigt surface waves.

Tom G Mackay,Chenzhang Zhou,Akhlesh Lakhtakia

doi:10.1098/rspa.2019.0317

Abstract

Electromagnetic surface waves guided by the planar interface of an isotropic dielectric medium and a uniaxial dielectric medium, both non-dissipative, were considered, the optic axis of the uniaxial medium lying in the interface plane. Whereas this interface is known to support the propagation of Dyakonov surface waves when certain constraints are satisfied by the constitutive parameters of the two partnering mediums, we identified a different set of constraints that allow the propagation of surface waves of a new type. The fields of the new surface waves, named Dyakonov–Voigt (DV) surface waves, decay as the product of a linear and an exponential function of the distance from the interface in the anisotropic medium, whereas the fields of the Dyakonov surface waves decay only exponentially in the anisotropic medium. In contrast to Dyakonov surface waves, the wavenumber of a DV surface wave can be found analytically. Also, unlike Dyakonov surface waves, DV surface waves propagate only in one direction in each quadrant of the interface plane.

Highlights

The planar interface of two dissimilar mediums, labelled A and B, supports the propagation of electromagnetic surface waves
A variety of different types of such surface waves can be guided by planar interfaces, depending upon the nature of the two partnering mediums [1,2]
The focus is on the planar interface of two dielectric mediums, medium A

Summary

Introduction

The planar interface of two dissimilar mediums, labelled A and B, supports the propagation of electromagnetic surface waves. Unlike other types of surface waves, such as the widely studied surface–plasmon–polariton waves [2,6,7], Dyakonov surface waves propagate without decay when both partnering mediums are non-dissipative [8,9] These surface waves represent attractive propositions for applications involving long-range optical communications. Two of the column 4-vectors are eigenvectors of a 4 × 4 propagation matrix [PA] for medium A, and the remaining two are eigenvectors of a 4 × 4 propagation matrix [PB] for medium B [13] These eigenvectors are chosen to ensure that the fields of the surface wave decay with distance from the planar interface.

Canonical boundary-value problem

Illustrative numerical studies on Dyakonov–Voigt surface-wave propagation

Closing remarks