Analysis on PBG Structure of Two-Dimensional Composite Triangular Photonic Crystal by Using FDTD Method

A composite triangular lattice photonic crystal is designed in this paper,the bandgaps of photonic crystal are studied by FDTD method.The calculated results obviously show that the crystal constructed from dielectric rods in the air background can generate a common band gap,which is called absolute photonic band gap,for both orthogonal polarization E and H.The absolute band-gap width is related to dielectric constants of the cylinders.The large differences between the dielectric constants of the cylinders and the air are useful to form the abslute photoric band gap,and the absolute photonic bandgaps move toward infrared wave.