A Concentric Double-Ring Resonator Based Plasmonic Refractive Index Sensor with Glucose Sensing Capability

This paper presents a refractive index sensor that includes two horizontal MIM (Metal-Insulator-Metal) waveguides coupled with a rectangular ohmic cavity and a Concentric Double-Ring Resonator (CDRR). The cavities contain the Material Under Sensing (MUS), while the surrounding area is filled with silver. The designed model is simulated using the Finite Element Method (FEM). Results from simulation show a linear shift of the resonant peaks for variations in the MUS refractive index. Therefore, unknown MUS is identified through peak shifts. The sensor achieves a maximum sensitivity of 1070 nm/RIU with the most sensitive geometry obtained from the simulations. Moreover, the ability to identify glucose concentration levels in the human blood samples makes the proposed sensor an attractive choice for bio-sensing applications.