Original research articleSurface plasmon resonance sensor based on D-type fiber with a gold wire

•Presentation of a concept and design of a refractive index optical sensor based on SPR using metallic wire.•Sensing with hybridized SPR modes supported by metal wires.•Analysis and optimization of the considered design parameters towards sensitivity optimization using COMSOL Multiphysics.•Comparison with conventional D-type fiber based on a metal film reveals performance improvement.

We propose a refractive index sensor based on surface plasmon resonance (SPR) in a gold wire partially incrusted on the surface of a D-type fiber and in contact with the external medium for increased sensitivity and roughness. The sensor is studied using numerical simulations based on the finite element method (FEM) and is compared with a more conventional D-type fiber SPR where the wire is replaced with a gold film. The numerical work estimates the sensitivity and resolution for different analytic refractive indexes (RI) in the range of 1.30-1.40, for a sensor based on the wavelength interrogation method. The results indicate that the use of the gold wire provides a better sensitivity when compared with the gold film, while supporting multiple peaks in different wavelengths, each with distinct values of sensitivity and resolution.