MIM Structure With Inverted M-Type Cavity for Sensing Applications

Herein, a high-sensitivity multifunctional nanosensor comprising a metal-insulator-metal (MIM) waveguide and an inverted M-type cavity (IMTC) is presented. Fano resonances are generated owing to the interactions between different light pathways. Two contrastive structures are proposed to illustrate that a proper interference area leads to better propagation characteristics. The influence of geometric parameters on sensing properties is studied. Four derived structures are investigated to discuss the main factor for improving sensitivity. The designed structure can detect temperature and NaCl solution concentration with sensitivities reaching 1.444 nm/°C and 6.6 nm/%, respectively. The designed structures can also potentially be applied to other nanoscale devices.