Highly Sensitive Plasmonic Sensor with a Coupled Split-Square-Ring Resonator

Abstract

A novel design for a highly-sensitive plasmonic sensor, consisting of metal-insulator-metal (MIM) waveguide with a coupled split-square-ring resonator, is presented and studied by two-dimensional (2D) finite-difference time-domain (FDTD) method in this paper. The simulation results show that the proposed sensor possesses a refractive index (RI) sensitivity up to 2040 nm/RIU with optimized structural parameters. In addition, a temperature sensitivity of −1.2 nm/◦C is determined. Numerical calculations indicate that the sensing performance can still be further improved via optimization of the structure. The compact waveguide structure may find important applications in areas of sensing and integrated circuits.