A Photonic Crystal of Metacylinder Inclusions #

Henry Putley, Sebastien Guenneau, Richard Craster

11:50 Wednesday in 4Q05.

Part of the Metamaterial modelling and design session.

Abstract #

A photonic crystal of metamaterial inclusions, or metacylinders, is shown to admit eigensolutions which are highly anisotropic in Bloch-wavenumber space. The metamaterial inclusions are modelled as a microstructured plate-array material, homogenized such that the interior field is composed of exclusively forward and backward propagating waves along the plate-array axis. Effective continuity conditions on the cylindrical boundary conjoin the interior and exterior domains, the latter of which is described with a multipole formalism. It is shown that the plate-array angle is the principal variable in controlling wave motion through the crystal, and through the tuning of this parameter it is possible to engineer symmetry-induced degeneracies in the crystal’s band-structure. Larger cells of a number of metacylinders can be designed to belong to particular point-groups, the symmetries of which can be broken to “crack-open” degeneracies in a crystal of a square fundamental cell. Placing such cells in conjoined ribbons of opposite symmetry-breaking perturbation gives rise to interface states, making the anisotropic inclusions a capable tool in controlling EM wave motion.