SPR based fiber optic sensor for refractive index sensing with enhanced detection accuracy and figure of merit in visible region

Abstract

We, theoretically, propose a surface plasmon resonance (SPR) based indium tin oxide (ITO)–silver (Ag) coated fiber optic sensing probe for refractive index sensing in visible regime of the electromagnetic spectrum. A comparative study of ITO+Ag coated probe with Ag coated probe and with ITO coated probe using their respective optimized film thicknesses is carried out. We show that the proposed probe is endowed with the better sensitivity characteristic of ITO and better detection accuracy (DA) characteristic of Ag, and can sense change in refractive index with enhanced DA and figure of merit (FOM) in the visible region.