三重晶格光子晶体方形点缺陷缺陷模特性研究

Study on Characteristics of Defect Modes of Square Point Defect Based on Triple Lattice Photonic Crystal

文中提出一种新型三重三角晶格光子晶体,应用平面波展开法(PWM)分析其带隙结构,应用时域有限差分法(FDTD)研究方形点缺陷的尺寸和旋转角度对缺陷模特性的影响。仿真结果表明,该光子晶体的光子禁带处于THz波段范围内,且禁带宽度很宽,达到0.195 62。当方形点缺陷旋转角度为10°时,改变点缺陷尺寸,此时缺陷模个数发生变化,并且随着点缺陷尺寸的增大,缺陷模波长往长波长方向移动;当方形点缺陷边长为22.5μm时,改变点缺陷旋转角度,此时缺陷模位置基本不变,但是缺陷模个数发生变化。

A novel triple triangular lattice photonic crystal is proposed in this paper. The band gap property is analyzed by the plane wave method and the effect of the square point defect on the characteristics of defect modes is researched by the finite difference time domain method. The simulation results show that the photonie band gap of the photonic crystal is in the THz wave band and the gap width is as large as 0. 195 62. When the rotation angle of the square point defect is 10° ,with the increase of the size length,the number of the defect modes will change and the wavelength of the defect modes move towards the longer wavelength. When the side length of the point defect is 22.5 μm, with the changing of the rotation angle, the number of the defect modes will change, but the corresponding wavelengths will not change.