Slab-thickness dependent band gap size of two-dimensional photonic crystals with triangular-arrayed dielectric or magnetic rods

The band structures of two-dimensional photonic crystals are investigated numerically. The examined photonic crystal has a substrate-slab-cover architecture, wherein the rods in the slab are either dielectric or magnetic and are arrayed triangularly. The material used for the substrate, the cover and the surrounding medium in the slab is the same. It was found that the bandgap size of z(odd) modes initially becomes larger as slab thickness increases, reaching a maximum value, after which, the band gap size reduces. A similar behavior for the slab thickness-dependent band gap size was also observed for slabs containing rods with higher magnetic permeability and lower dielectric permeability, except that there was a shift toward lower values for the band gap size. A detailed discussion on the influence of the magnetic permeability of rods on the band gap size of z(odd) modes is also given. (C) 2003 American Institute of Physics.