基于氮化镓的导模共振滤波器仿真分析

摘要

In the light of the rigorous coupled wave theory and equivalent medium theory,this paper presents the structure of and design method for GaN-based subwavelength guided-mode resonant grating filters for C band of optical communications and discusses in detail the effects of grating period and incident angle on the resonant wavelength of the filter reflectance spectrum under the actions of high duty cycle of strongly modulated grating.While keeping the filtering effects as high diffraction effi-ciency (resonant wavelength peak reflectivity above 99.5%),low sideband reflection and narrow linewidth,it uses its sensitivi-ty to the incident angle and in combination with the numerical simulation presents a method for tuning the incident angle (0~4.07°)by a MEWS planar reflector,thus linearly controlling the resonant wavelength output in a tuning range of 36 nm and re-alizing a tunable filter with FWHM lower than 0.8nm for C band of optical communication networks.%根据严格耦合波理论和等效介质理论，提出了针对C波段、基于半导体材料氮化镓的亚波长导模共振滤波器结构及设计方法。详细探讨了在强调制光栅的高占空比作用下，光栅周期和入射波角度对滤波器反射谱共振波长的影响。在保持滤波效果为高衍射率(共振波长峰值反射率达到99.5%以上)、低旁带和窄线宽的条件下，利用其对入射波角度的敏感性，结合仿真数值提出了一种通过 MEMS(微机电系统)平面反射镜调谐入射角角度(0~4.07°)，从而线性地控制共振波长输出(调谐范围为36 nm)，实现峰值半宽高低于0.8 nm的C波段可调滤波器。