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.