A super continuum characterized high-precision SPR fiber optic sensor for refractometry

•High-precision SPR fiber optic sensor for refractometry.•Fabrication of a high sensitive optical fiber based SPR sensor to work in aqueous environments.•Fabrication of high quality D-shaped fibers.•Improving LOD of the fiber sensor by reducing intensity noise in the light source.•Fabrication of side-polished fiber optic sensor using Controllable Hybrid Polishing Method (CHPM).

Here we introduce a high sensitive side-polished fiber optic based surface plasmon resonance (SPR) sensor for refractometry in liquids for 1.32–1.37 Refractive Index Unit (RIU). In fabrication, a Controllable Hybrid Polishing Method (CHPM) was used to make high quality D-shaped fibers. For characterization, a super continuum (SC) light source was used in the measurement setup. The sensor has a spectral sensitivity of 5200 nm/RIU with a Limit of Detection (LOD) of 5.8 × 10−6 RIU. Also, we have demonstrated that by reducing the intensity noise in our light source, a Signal-to-Noise Ratio (SNR) of 12.6 dB and a Limit of Detection (LOD) of 3.7 × 10−6 RIU is achievable in an intensiometric approach.