School of Mathematics

Tom Mackay has been awarded an EPSRC New Horizons grant entitled Exciting Voigt Surface Waves

Tom Mackay has been awarded an EPSRC New Horizons grant entitled Exciting Voigt Surface Waves. Electromagnetic surface waves propagate at the interface of two dissimilar partnering materials. Since the beginning of the twentieth century, several different types of electromagnetic surface wave have been identified. Very recently two new types of electromagnetic surface wave were theoretically discovered. These new types of electromagnetic surface waves differ fundamentally from all previously known types of electromagnetic surface waves by the manner in which these surface waves are localized at the interface. The unique localization properties of these new surface waves lend themselves to applications involving optical communications and optical sensing, for examples. To date, the theory developed only establishes the existence of these new surface waves for an idealized configuration. The question of how these surface waves may be excited in a practical configuration has not yet been addressed. It is proposed to further develop the theory to accommodate the excitation of these new surface waves for practical configurations. This research involves coupling the interface of the partnering materials to incident light by means of a prism or alternatively by means of a diffraction grating. Furthermore, the theory developed to date only establishes the existence of these new surface waves for the simplest possible partnering materials. Considerably greater scope for these new surface waves is offered by more complex partnering materials. It is therefore proposed to develop the theory to accommodate more complex partnering materials, including bianisotropic partnering materials and nonhomogeneous materials. Bianisotropic materials offer much greater scope for surface-wave propagation than do anisotropic or isotropic materials, because of intrinsic coupling between electric and magnetic fields and the much larger constitutive parameter space that is associated with bianisotropic materials. Such complex partnering materials may facilitate the excitation of multiple surface waves, which is a desirable property for potential applications in optical communications and optical sensing, for examples.