本文利用方形谐振器与两个金属／介质／金属型波导结构耦合设计了一个亚波长的表面等离子体波导传感器,并通过有限元分析研究了此结构的传输特性。研究表明,通过谐振器耦合能有效增强共振波长的表面等离子体波的透射能力,同时减小两侧波导结构与方形谐振器之间的金属势垒层宽度可提高透射率。传感器的共振波长与介质材料的折射率之间存在着线性关系,1阶共振模的灵敏度可达1100 nm／RIU。这种传感器可实现器件的小型化,在生物、工业传感领域有着很大的潜力。

A nanoscale sensor based on a square resonator coupled with two metal-insulator-metal Surface Plasmonic Waveguides was designed in this paper, and the Finite Element Method was introduced to study the transport properties of the structure. The results showed that the transmission capacity can be effectively enhanced by resonator coupling, while reducing the width of the metal barrier layer on both sides between the square resonator and the waveguide can also improve transmittance. Besides, the resonance wavelength of the sensor has linear relationships with the refractive index of the insulator,its first-order resonance mode sensitivity could be as high as 1 100 nm／RIU. The sensor can be miniaturized so that it has great potential in the biological and industrial sensing field.