We know periodic arrangement of dielectric spheres in the wurtzite structure generate photonic band gap. As the dielectric constant ratio increases, the size of the relative gap saturates to a value of 18% for the case of filling ratio 34%. Otherwise one basis triangular lattice exhibits common photonic band gap for only case that dielectric constant rod is lower than that of background, two basis triangular lattice exhibits common photonic band gap for its a opposite case as well as above case. For the dielectric constant ratio increasing, the size of relative gap don't saturates but decreases. It is due to bands crossing of TE mode and TM mode.
