Numerical Investigation of Nanodots Implanted High-Performance Plasmonic Refractive Index Sensor

A plasmonic refractive index sensor focused on a square ring resonator (SRR) and a circular ring resonator (CRR), coupled to a metal-insulator-metal (MIM) bus waveguide and a rectangular stub is proposed. The structure is numerically investigated using the Finite Element Method (FEM) by positioning nanodots (NDs) at highly confined E-filed region. The evident effect of refractive index (RI) on resonant wavelength is employed to sense the materials. A maximum sensitivity of 2850 nm/RIU was obtained by the optimized design, and associate figure of merit (FOM) and quality factor (Q-factor) recorded are 105.95 and 71.71, respectively. The structure’s high tolerance for possible manufacturing flaws makes it easy-to-manufacture. With compact size, superior performance, and narrow resonance dip, the proposed sensor is expected to be an excellent candidate for biosensing, gas sensing and lab-on-chip applications.