基于表面等离子激元的凸环结构金属-介质-金属滤波器设计

Design on the Convex Ring MIM Structure Filter Based on Surface Plasmon Polaritons

利用边界耦合的方法构造了金属-介质-金属结构滤波器,该结构由一个凸环谐振腔与一个波导管耦合而成.通过有限元法数值仿真得到了该凸环腔体波导结构的磁场分布图、透射谱线和谐振波长分布,分析了各结构参量对滤波器传输特性的影响.结果表明,所提出的凸环滤波器具有透射峰窄,谱线平滑等特点,且阻带透射率最低可达0.001,通带透射率最高可达0.977.增大结构参量h2和neff时,相应的透射谱会发生明显的红移,增大结构参量L1时,透射谱几乎无变化.对结构参量进行调整和优化,相应的谐振波长可分布在第一通信窗口(850nm)和第三通信窗口(1 550nm)附近,能够很好地运用于光通信中.

A novel Metal-Insulator-Metal (MIM) structure filter was constructed by using the boundary-coupled method.The structure consists of a convex ring resonator and a waveguide.The magnetic field distribution,transmission spectra and resonance wavelength distribution of the convex ring cavity waveguide structure were obtained by Finite Element Method (FEM) numerical simulation.The influence of various structural parameters on the transmission characteristics of the filter is analyzed in detail.The results show that the proposed convex ring filter has narrow transmission peaks,smooth transmission spectra and other characteristics,and the minimum stopband transmission rate can reach 0.001,and the passband transmittance can reach 0.977.When the structural parameter h2 and neff is increased,the corresponding transmission spectrum undergoes a significant red shift.When the structural parameter L1 is increased,the transmission spectrum hardly changes.By adjusting and optimizing various structural parameters of the structure,the resonance wavelengths can distribute in the vicinity of 850 nm (the first communication window) and 1550 nm (the third communication window),and can be well used in communications.