Conditions for surface plasmon resonance excitation by whispering gallery modes in a bent single mode optical fiber for the development of novel refractometric sensors

Abstract

This paper discusses a novel technique for high-precision refractometric measurements using surface plasmon resonance (SPR). A new SPR sensor configuration is proposed wherein surface plasmon resonance is excited on the metal-coated outside of a bent single mode optical fiber by whispering gallery modes. The conditions for SPR excitation and registration of SPR wavelength are discussed. The best metal for the proposed sensor configuration is found to be silver. Calculations are carried out on the dependence of SPR wavelength on the measured refractive index. The maximum resolution of refractometric measurements by the proposed technique is estimated at ∼10−8.