Optimization design of structure parameters of 2D triangular lattice for big photonic band gap

Optimization design of photonic crystals is an important content of theoretically investigation.Plan Wave Expansion Method is used to simulate the photonic band gap(PBG) of 2D triangular lattice photonic crystals of circular column and square column and hexagonal column.When the dielectric materials are GaAs,Si and Ge,the influence of rods shape,rotation angle,filling rations on absolute photonic band gap are discussed.Conclusions as blow: For 2D triangular lattice photonic crystals,air rods are easier to obtain absolute PBG than dielectric rods.And compared with circular rods or square rods,hexagonal rods have the biggest complete PBG width: Δmax=0.116(ωa/2πc).In a word,for 2D triangular photonic crystals,the optimum structure is hexagonal air rods,where dielectric is Ge,d/a equals to 0.92,θ equals to 18°.This result can provide theoretical instruction for 2D triangular photonic crystals with big photonic band gap.