Influence of dopants on the performance of a fiber optic surface plasmon resonance sensor

In this paper, a theoretical analysis is carried out to estimate the sensitivity and the signal-to-noise ratio (SNR) of a fiber optic surface plasmon resonance (SPR) sensor when fibers with different dopants and different doping concentrations are used. The dopants considered are germanium oxide (GeO₂), boron oxide (B₂O₃), and phosphorus pentoxide (P₂O₅) in a pure silica fiber. The variation of the dispersion relation with different dopants and doping concentrations are taken into account for the analysis. It is shown that the doping of B₂O₃ increases the sensitivity of the sensor while the effect of dopant on SNR is negligible. The analysis is extended to fiber optic SPR sensor with bimetallic layers.