Simulation and experiments for optimizing the sensitivity of curved D-type optical fiber sensor with a wide dynamic range

A curved D-type optical fiber sensor (OFS) based on surface plasmon resonance (SPR) is proposed. The parameters, such as the curvature of the fiber, the unpolished depth of the fiber core, the thickness of the deposited gold films, and the incident angle of light upon the gold-deposited surface, affect the sensitivity of this curved OFS. Calculation, simulation, and experiments are performed to optimize the sensitivity by choosing suitable parameters. The feasibility of this curved D-type OFS is demonstrated by monitoring the SPR phenomena of ethylene glycol solutions with different refractive indices. This OFS is applicable as a biosensor for label-free, real-time, and in-situ characterization of biomolecular interactions.