Effect of size nonuniformities on the band gap of two-dimensional photoniccrystals

The effects of size nonuniformities in two-dimensional photonic crystals ar e studied by using the plane-wave expansion and the supercell methods. Squa re, triangular, and graphite arrays of dielectric rods or air holes are inv estigated 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 s ignificant for the amount of size nonuniformities which could occur during fabrication. It is interesting to find that the higher-order absolute photo nic band gap existing in the graphite structure is also tolerant to the siz e fluctuation. [S0163-1829(99)03908-9].