二维异质结光子晶体中含近邻点缺陷的弯曲波导的可调谐滤波特性

应用时域有限差分(FDTD)法,对光在二维异质结光子晶体中含两个近邻点缺陷直角弯曲波导的传输特性进行了数值模拟研究。计算结果表明,具有特定本征共振频率的光子晶体微腔(点缺陷),可将在其邻近波导中传播的相同频率成分的光波"引入"到微腔中。"引入"的频率依赖于异质结光子晶体弯曲波导和微腔的参量,从而能够实现调变"引入"频率。通过改变点缺陷周围介质材料(液晶)的折射率或相关介质柱半径,可分别实现约31 nm或12 nm的波长调谐范围。计算结果为光通信中的调谐、上/下载滤波器,提供了一条新的设计思路和依据。

Tunable Optical Filter Based on Two-Dimensional Heterostructure Photonic Crystal with Neighboring Dot-Defects and Curved Waveguide

Tunable optical filter based on two-dimensional heterostructure photonic crystal is formed by curved waveguides and neighboring cavities when line and dot defects are introduced into heterostructure photonic crystal.Finite-difference time-domain(FDTD) method is used to analyze the filter.Results showed that the waves with certain frequencies in the waveguide could be introduced into the cavity when resonance coupling occured.The introduced frequency depends on parameters of curved waveguide and cavities in the heterostructure photonic crystal.When the refractive indices of neighboring medium or radius of the rods were changed,a wide transmission region of 31 nm or 12 nm could be realized respectively.Our results provided a new design method and bases improving the efficiency of add/drop and realizing the tunability of filter.