Irreducible First Brillouin-Zone for Two-Dimensional Binary-Compound Photonic Crystals

Abstract

Detailed calculations are carried out for band structures in the whole area of the first Brillouin zone (BZ) for two-dimensional binary-compound photonic crystals (PCs) with the square lattice. This kind of PCs is shown to alter its irreducible BZ, depending on the position of the second atom, because of the introduction of the spatial anisotropy into the unit cell. In particular, the PCs with very asymmetric atomic configurations are forced to render the whole first BZ irreducible. Only the investigation throughout the BZ is thus known to permit us to obtain the authentic band structures for this kind of PCs.