Highly Sensitive D-Shaped PCF Based Plasmonic Refractive Index Sensor

Abstract

A D-shaped highly sensitive plasmonic resonance sensor for low refractive index (RI) detection is proposed in this work. Plasmonic material layer and the sensing layer have been placed outside of the fiber structure in order to sense the changes in refractive index of the surrounding medium. Titanium dioxide (TiO ₂ ) is used as an adhesive agent and coated between silica glass and the plasmonic material to establish strong coupling between core mode and plasmonic mode. Proposed sensor shows maximum Wavelength Sensitivity (WS) of 75,000 nm/RIU with resolution of 1.33×10 ^-6 RIU and maximum figure of merit (FOM) 1500 for analyte RI range of 1.25-1.40. These properties make the proposed sensor a suitable candidate for bio sensing, organic chemical sensing and other analytes detection.