Surface Plasmon Resonance-based Refractometry Using Whispering Gallery Modes in Bent Metalized Single-mode Optical Fibers.

The work is devoted to the numerical and experimental study of surface plasmon resonance in a bent singlemode optical fiber with metalized cladding. It was shown that with a proper combination of metal film thickness and bend radius one can achieve coupling between fundamental and surface plasmon modes through an intermediary of whispering gallery mode supported by the bent fiber's optical cladding. This brings about a dip in the transmission spectrum of the fiber at the resonant wavelength which depends strongly on the external medium refractive index, so that refractometric measurements can be performed with a sensitivity of ~5 μm/RIU and resolution ~4·10^-6. [ABSTRACT FROM AUTHOR]