Fluoride Fiber-Optic SPR Sensor With Graphene and NaF Layers: Analysis of Accuracy, Sensitivity, and Specificity in Near Infrared

Surface plasmon resonance (SPR) based fluoride fiber-optic sensor with graphene and sodium fluoride layers is simulated and analyzed in near infrared (NIR) for detection of alcohols. Through this paper, the fluoride fiber has been employed for the first time in SPR sensing application. The proposed fiber optic sensor is analyzed under angular interrogation method, which is based on on-axis launching of monochromatic light into the fiber core at varying angle followed by measuring the power transmitted through the SPR probe region. The sensor's specificity towards alcohols plus a significantly increased sensitivity and accuracy are ensured by a polythiophene layer. The results indicate that longer NIR wavelength (λ) provides superior sensing performance. Further, the proposed sensor's performance can be significantly enhanced by tuning the chemical potential (μ) of graphene monolayer. In summary, monochromatic light of λ = 1550 nm and 0.65 eV <; μ <; 0.70 eV provides substantially high performance in terms of sensitivity, accuracy, and figure of merit. The proposed sensor has the capability to provide significantly better performance than previously-reported SPR sensors.