Surface modes in a 2D array of square dielectric cylinders

Abstract

We have studied surface modes in a dielectric array of parallel cylinders having a square cross-section and forming a square lattice. The surface plane is parallel to one cylinder side, itself parallel to one side of the (square) unit cell. We have found that surface electromagnetic modes can propagate along the surface in the direction perpendicular to the cylinders. The properties of these modes are strongly dependent on the position of the surface, that is on the cut-plane through the cylinders. They can propagate for both complete and incomplete (truncated) layers of cylinders and can exist within incomplete band-gaps. The modes reported here are characterized by a maximum value of the propagation constant, determined by a bulk band or by the crossing of two such bands.