A model of a refractive fiber optic sensor sensing element based on MMF-SMF-MMF structure using surface plasmon resonance

This paper presents a mathematical model of the sensitive element refractometric fiber-optic sensor principle operation which is based on phenomenon surface plasmon resonance. The sensing design sequential connection multimode fiber (MMF), single-mode (SMF), and forming an MMF-SMF-MMF structure. SMF site coated with thin film gold. To element, approach used in calculating classical Kretschmann configuration for volumetric optical structures was applied. refractive index calculated Sellmeyer equation, gold determined using Drude model. simulation results are compared experimentally obtained transmission spectra fabricated samples elements. For approbation model, elements sensors following parameters made: core diameter 62.5 μm, singlemode 9 coating SMF-segment 50 nm film. Transmission aqueous glucose solutions various concentrations were obtained. It demonstrated that proposed describes well region can be to optimize order increase sensitivity. implies its use development algorithm interrogation structures.