采用有限元方法设计了一种基于金属-电介质-金属(MIM)的内嵌对称扇形金属块的纳米圆形谐振腔滤波器。研究发现,通过改变扇形共振角度、圆形谐振腔半径、耦合距离、共振腔内的介质折射率等主要参数可有效调节该结构的透射特性。该滤波器同时出现两个显著的共振峰,透射率最高可达76%,品质因子最高可达40,能高效实现可调谐双通道带通滤波功能。对结构参量进行调整和优化,相应的谐振波长可分布在近红外波段光纤通信的850 nm和1310 nm通信窗口。该结构为设计光通信领域下一代高性能微纳等离子体滤波器提供了重要的理论依据。

In this study, a nano-circular resonant cavity filter embedded with a symmetrical sector metal block based on metal-insulator-metal (MIM) is developed using the finite element method. It is found that by changing parameters such as the sector resonance angle, circular resonant cavity radius, coupling distance, and refractive index of medium in the resonant cavity, one can effectively adjust the transmissivity characteristics of the proposed structure. The filter shows two significant resonance peaks with the transmissivity up to 76% and quality factor to 40, which is suitable for efficiently achieving a tunable dual-channel bandpass filter. The parameters of the proposed structure are adjusted and optimized to enable the corresponding resonant wavelengths distributed in the 850 nm and 1310 nm optical communication windows of near-infrared band optical fiber communication. This structure provides an important theoretical basis for designing the next-generation high-performance nano-plasmonic filters in the field of optical communication.