Two-dimension Photonic Crystal Complete Bandgap

Photonics crystal(PhC)is the material in which the refractive index changes periodically and the PhC has a band structure and location mode,this structure can control light.In order to study two-dimensional PhC complete band gap,in this paper,plane wave expansion method was employed to simulate four types of two-dimensional PhC.We study the relationship between the complete bandgap and the variation of column radius r with a fixed lattice constant.We found that hexagonal lattice PhC air holes complete band gap appears in the r=0.42～0.50 μm range,complete band gap width does not increase with the air column radiu r,but there is a maximum width.The maximum band gap width is Δω1=0.08(ωa/2πc).When air column radiu r=0.47～0.50 μm,square lattice PhC exists complete bandgap,the band gap width Δω2=0.02(ωa/2πc).And complete band gap center frequency increases with r.Results indicate that for hexagonal and square GaAs columnar PhC there is no complete band gap.