A plasmonic structure composed of a metal–insulator–metal waveguide, a stub cavity, a T-shaped cavity (T-SC), and a split-rectangular cavity (S-RC) is proposed and investigated using the finite element method. The results demonstrate triple Fano resonances in the transmission spectrum due to the interaction between cavities. The maximum sensitivity and figure of merit were 1600 nm RIU⁻¹ and 14 455, respectively. The Fano resonance can be independently modulated by changing the structural parameters of the T-SC or S-RC, and a new Fano resonance can be generated by breaking the symmetry of the structure. Through the addition of three semi-ring cavities and a semi-disk cavity to the original structure, we obtained eight ultra-sharp and asymmetric Fano resonances, which improved the integration and performance of the structure. Therefore, the proposed device has potential applications in refractive index sensors, optical communication areas, and multi-control Fano switches.

提出并使用有限元方法研究了由金属-绝缘体-金属波导、短截线腔、T 形腔 (T-SC) 和分裂矩形腔 (S-RC) 组成的等离子体结构。结果表明，由于腔之间的相互作用，透射光谱中出现了三重法诺共振。最大灵敏度和品质因数为 1600 nm RIU ^-1和 14 455，分别。Fano共振可以通过改变T-SC或S-RC的结构参数来独立调制，破坏结构的对称性可以产生新的Fano共振。通过在原有结构上增加三个半环腔和一个半圆盘腔，我们获得了八个超锐利和非对称的Fano共振，提高了结构的集成度和性能。因此，所提出的器件在折射率传感器、光通信领域和多控制 Fano 开关方面具有潜在的应用。