Two Dyakonov–Voigt surface waves guided by a biaxial–isotropic dielectric interface

Abstract

Electromagnetic surface waves guided by the planar interface of an orthorhombic dielectric material and an isotropic dielectric material were analyzed theoretically and numerically. Both naturally occurring minerals (crocoite, tellurite, and cerussite) and engineered materials were considered as the orthorhombic partnering material. In addition to conventional Dyakonov surface waves, the analysis revealed that as many as two Dyakonov–Voigt surface waves can propagate in each quadrant of the interface plane, depending upon the birefringence of the orthorhombic partnering material. The coexistence of two Dyakonov–Voigt surface waves marks a fundamental departure from the corresponding case involving the planar interface of a uniaxial dielectric material and an isotropic dielectric material for which only one Dyakonov–Voigt surface wave is possible. The two Dyakonov–Voigt surface waves propagate in different directions in each quadrant of the interface plane, with different relative phase speeds and different penetration depths. Furthermore, the localization characteristics of the two Dyakonov–Voigt surface waves at the planar interface are quite different: the Dyakonov–Voigt surface wave with the higher relative phase speed is much less tightly localized at the interface in the isotropic dielectric partnering material.

Exceptional surface and compound waves

“…35 The planar interface of an isotropic dielectric medium and a uniaxial dielectric medium supports one Dyakonov-Voigt surface wave in each quadrant of the interface plane, 33,34 whereas the planar interface of an isotropic dielectric medium and a biaxial dielectric medium supports up to two Dyakonov-Voigt surface waves in each quadrant of the interface plane. 36 Furthermore, the planar interface of a biaxial dielectric medium and a uniaxial dielectric medium supports doubly exceptional Dyakonov-Voigt surface waves. 32 (b) The exceptional surface waves known as surface-plasmon-polariton-Voigt waves can arise if one of the partnering mediums is metallic and the other is dielectric, with at least one of the partnering mediums being anisotropic.…”

Exceptional Guided Waves

“…These exceptional waves can arise if the partnering materials are nondissipative [17] or dissipative [18]. For example, while the planar interface of an isotropic dielectric material and a uniaxial dielectric material supports one exceptional surface wave for each quadrant of the interface plane, the planar interface of an isotropic dielectric material and a biaxial dielectric material supports two exceptional surface waves for each quadrant of the interface plane [19]. Doubly exceptional Dyakonov-Voigt surface waves have been reported on for the planar interface of a biaxial dielectric material and a uniaxial dielectric material [16].…”

Exceptional compound plasmon-polariton waves

“…Greater scope for exceptional CPP waves is likely to be presented by scenarios in which more than one of the materials in the trimaterial structure is anisotropic. In particular, if the one (or more) of the materials in a trimaterial structure is biaxial, then the prospect of multiple exceptional CPP waves arises [34]. These are matters for future investigation.…”