SPR based fiber-optic sensor with enhanced electric field intensity and figure of merit using different single and bimetallic configurations

We present numerical simulations of electric field intensity, sensitivity and figure of merit (FOM) for different single and bimetallic configured surface plasmon resonance (SPR) fiber optic sensors. The metals considered are gold (Au), silver (Ag), copper (Cu) and aluminum (Al). The overall performance of the sensor is evaluated in terms of electric field intensity, sensitivity, FOM, chemical stability and the cost of fabrication of the sensor. More specifically, in terms of the sensing parameters, Al and Cu bimetallic configuration is found to be much better than the single and the other bimetallic configured sensors. The bimetallic configuration of Al and Cu for fiber optic SPR sensor is also evaluated experimentally. Additionally, the film adhesion capability of both the materials gets improved when used in bimetallic combination which further improves the chemical stability of the sensor; this is a serious problem with Al and Cu in their single layer configuration. The combinations which possess gold as outer layer are more chemically stable but found to be weaker in terms of sensing parameters and cost of fabrication as gold is highly expensive. (C) 2016 Elsevier B.V. All rights reserved.