Effect of size nonuniformities on the band gap of two-dimensional photonic crystals

The effects of size nonuniformities in two-dimensional photonic crystals are studied by using the plane-wave expansion and the supercell methods. Square, triangular, and graphite arrays of dielectric rods or air holes are investigated in this study. The reduction of the first photonic band gap in TM or TE modes of square and triangular structures turns out to be not very significant for the amount of size nonuniformities which could occur during fabrication. It is interesting to find that the higher-order absolute photonic band gap existing in the graphite structure is also tolerant to the size fluctuation. [S0163-1829(99)03908-9].