Complex photonic band structures of a conductive metal lattice by a quadratic eigensystem

Abstract

For conductive periodic media, Maxwell’s equations can be transformed into quadratic eigensystems by the plane-wave expansion method. We computed complex photonic band structures for the two-dimensional square lattice with conductive cylinders by solving the quadratic eigensystem. The photonic band structures obtained for metal cylinders with finite conductivity closely resemble those computed for perfectly conductive cylinders by a real space finite-difference method. However, some modes can become unphysical in the finitely conductive metal lattice.