Design and analysis of highly sensitive prism based surface plasmon resonance optical salinity sensor

This research presents a highly sensitive surface plasmon resonance (SPR) optical salinity sensor based on angular interrogation method for the quantification of salinity and desalination of sea water. The proposed salinity sensor structure composed of prism-silver (Ag)-silicon (Si)-Franckeite-sensing medium. To achieve the best possible performance i. e. sensitivity, detection accuracy, and quality factor, the sensor is designed and simulated at different wavelengths of 633 nm, 643.8 nm, 690 nm, 700 nm, and 720 nm. The performance of the sensor has also been optimized for different thickness of Ag layer, Si layer, and no. of layer of 2D franckeite. An enhanced maximum sensitivity of 305 deg./RIU is obtained with detection accuracy 0.41 deg.-1 and quality factor 63.92 RIU-1. As the sensor provides high grade of performance, this can be used as a salinity sensor for the desalination of seawater.