高下路空气孔型光子晶体环形谐振腔的设计

Design of High-drop Hole-type Photonic Crystal Ring Resonators

提出一种基于二维正方晶格光子晶体空气孔型高下路效率的环形谐振腔,通过压缩线缺陷波导的宽度实现单模有效控制,同时讨论内围光子晶体列数对传输场的影响,然后运用二维时域有限差分方法数值分析了耦合强度及环区局部折射率调制对下路效率、品质因子以及下路波长等参量的影响.结果表明:当波导宽度为0.7个晶格常量,耦合强度为0个晶格常量,在信道波长为1 528.1nm时,下路效率为99%,品质因子Q为379;当耦合强度提高到1个晶格常量,下路波长稍微漂移为1 524.3nm,品质因子显著提高到1 397,而下路效率下降为89%.同时,下路波长会随着环区折射率的增加呈线性红移.

A high-drop air-hole-type photonic crystal ring resonator(PCRR)was proposed based on twodimensional square lattice configuration.The single mode operation can be realized by compressing the width of bus waveguide.The impact of number of rows of holes on the propagating field intensity distribution was also analyzed.The physical parameters,such as dropping wavelength,dropping efficiency and spectral quality factor(Q)affected by changing the localized refractive index of inner ring and coupling strength between bus waveguide and PCRR,were numerically demonstrated based on two-dimensional(2D)finite-difference time-domain(FDTD)technique.It shows that 99% dropping efficiency and 379 Q can be obtained at 1 528.1nm signal channel when the width of bus-waveguide and coupling strength are 0.7-periodicity and 0-periodicity,respectively.On the other hand,when the coupling strength increases to 1periodicity,the Qcan be improved by 1 397with the decreased dropping efficiency by 89%.Besides,the dropping wavelength can be linearly increased with the increase of localized refractive index of inner ring.