Surface plasmon resonance based fiber optic sensor using an additional layer of platinum: A theoretical study

Surface plasmon resonance (SPR) based fiber optic sensor with bimetallic layers of Au/Ag/Cu-Pt is theoretically studied. The outer Pt layer over Au/Ag/Cu layer is shown to enhance the sensitivity of SPR sensor. For a fixed thickness of Au/Ag/Cu layer, the sensitivity increases with increase in Pt layer thickness. Sensitivity also enhances with increase in thickness of Au/Ag/Cu layer for all thicknesses of Pt layers. Besides, Au-Pt bimetallic layers based SPR sensor possesses higher sensitivity than that of Ag-Pt and Cu-Pt bimetallic layers. 50 nm Au-20 nm Pt based SPR sensor exhibits maximum sensitivity of 3571 nm/RIU.