High Sensitivity Plasmonic Sensor Based on Metal–Insulator–Metal Waveguide Coupled with a Notched Hexagonal Ring Resonator and a Stub

Abstract

In this paper, a compact and highly sensitive refractive index plasmonic sensor, with a metal-insulator–metal waveguide coupled with a notched hexagonal ring resonator and the stub is proposed. Structural parameters of the sensor have a key role in the sensor’s sensitivity and transmission spectrum, which are investigated using the finite-difference time-domain method embedded in the commercial simulator R-Soft. The results yield a linear link with the refractive index of the material under testing and its wavelength resonances. Moreover, the maximum linear sensitivity is S = 2547 nm/RIU, its corresponding sensing resolution is 3.92 × 10−6 RIU. Therefore, this sensor can be implemented in high-performance nano-sensors and bio-sensing devices. In this proposed structure, the positions of transmission peaks can be easily manipulated, by adjusting the length and width of the stub.