【摘要】 设计了一种金属-绝缘体-金属(MIM)型表面等离激元波导结构.该结构由环形开口谐振腔(CSRRC)和双对称矩形短柱波导(DSRSW)组成.有限元方法(FEM)用于研究结构的传输特性.结果表明,DSRSW激发的宽带连续状态与CSRRC激发的窄带离散状态之间的耦合产生了双Fano共振.Fano共振的共振波长和线形可以通过结构的几何参数来调整.优化几何参数后,结构的灵敏度可以达到821nm/RIU,品质因数(FOM)可以达到2001.该结构在折射率传感器和全光开关器件方面具有潜在的应用.更多还原

【Abstract】 In this paper, a metal–insulator–metal(MIM) type surface plasmon waveguide structure is designed, which is composed of a circular split-ring resonance cavity(CSRRC) and a double symmetric rectangular stub waveguide(DSRSW). The finite element method(FEM) is used to investigate the transmission characteristics of the structure. The results show that the interference between the wide-band continuous state excited by the DSRSW and the narrow-band discrete state excited by the CSRRC produces double Fano resonances. The resonance wavelength and line shape of the Fano resonance can be tuned by the geometric parameters of the structure. After optimizing the geometric parameters, the sensitivity of the structure can be up to 821 nm/RIU, and the figure of merit(FOM) can be up to 2001. This structure has potential applications in refractive index sensors and all-optical switching devices.更多还原