通信波段硅基气孔光子晶体的带隙特性及其物理模型研究

用平面波展开法对硅背景下的通信波段不同晶格类型和气孔形状光子晶体的能带结构进行数值计算与分析,提出了相应的物理模型.结果表明:利用光子受限效应和晶格对称性效应可以有效地调控光子带隙.随光子晶体填充率的增加,其约束光子的能力增强,光子带隙在一定范围内展宽且其中心频率蓝移;带隙随晶格对称性增加而变宽.对基元形状和旋转角度的研究发现,光子带隙随基元旋转角度变化具有周期性和对称性,表现出各向异性,由此优化出对应的不同晶格的最佳谐振腔型结构.

A physical model for band gap of silicon-based photonic crystal of air hole at telecom wavelengths

Band structures of silicon photonic crystal (PC) with different lattices and shapes of air holes at telecom wavelengths were investigated by plane-wave expansion method, and the related physical models were proposed. Calculated results demonstrate that photonic band gap (PBG) can be effectively manipulated by photon confinement effect and lattice symmetry effect. With the increase of filling fraction, the ability with which photons are confined by PC is enhanced, PBG is opened and the central frequency undergoes a blue-shift. PBG is enlarged as the lattice symmetry increases. Shape and rotation of lattice element are also studied. Band gap with the rotation angle which follows periodicity and symmetry indicates its anisotropy. The optimal cavity structures for different lattices are also found.