采用平面波展开法和时域有限差分法, 对GaAs二维正方晶格光子晶体的色散特性和带隙结构进行了数值模拟研究, 并对GaAs二维光子晶体线缺陷构成的T型波导分支器的微波传输特性进行了模拟和优化。数值模拟结果表明, 光子晶体填充比对带隙结构有显著地影响。通过在拐角处插入额外的电介质棒对GaAs二维正方光子晶体T型波导分支器进行优化, 数值模拟的结果表明, 优化的GaAs二维正方光子晶体T型波导分支器在一阶带隙范围内透射系数将提高到0.96以上。

The dispersion properties and bandgap structure of infinite two-dimensional GaAs square lattice photonic crystals are simulated through plane wave expansion method and finite difference time domain method. The microwave transmission characteristics of GaAs photonic crystal T-shaped splitter are simulated and optimized. Numerical simulation results show that the bandgap structure is determined mainly by ratio of the post radius to the post spacing. Two-dimensional GaAs square lattice photonic crystal T-shaped splitter is optimized by inserting extra dielectric rods in the corner. The transmission coefficient of this optimized structure could be more than 0.96 within the first bandgap.