DESIGN OF PHOTONIC CRYSTAL SLAB STRUCTURES WITH ABSOLUTE GAPS IN GUIDED MODES

Abstract

Both symmetric and asymmetric photonic crystal slabs with non-circular holes have been investigated. An absolute band gap was found for a triangular lattice of hexagonal holes in both symmetric and asymmetric slabs, but a square lattice of square holes has an absolute bandgap only in symmetric slabs. The band gap could be maximized by optimizing the angular orientation of the holes with respect to the lattice, leading to a larger gap than can be obtained with circular holes. The slab thickness was found to be an important tuning parameter for obtaining an absolute bandgap, and the sensitivity of the gap size to this parameter is shown.