The Dispersion Characteristic of 2D Air-Hole-Type Square Photonic Crystal Calculated by Piane Wave Expansion Method

摘要

To study the dispersion characteristic of photonic crystal, the eigen-equations matrix of the light transmitting in is gotten in plane-wave expansion method, then the dispersion curves are calculated for two dimensional air-hole-type square photonic crystal respectively. And the influence on the band structures caused by oblique incidence also is studied by change incidence angle.The results of calculations demonstrate that: For two dimensional square structure photonic crystals, the shape of the band structures of TE mode is very similar to that of TM mode, but their positions of band gaps are different, especially the first band gap of TE mode in the square structure in <11> direction is completely staggered with that of the TM mode. Moreover, we get the conclusion that the width of band gap enlarges with the increasing radius of the hole in square photonic crystal in <10> direction.