Opening up dual-core microstructured optical fiber-based plasmonic sensor with large detection range and linear sensitivity

An opening up dual-core microstructured optical fiber based surface plasmon resonance sensor is numerically investigated for the measurement of a broad refractive index (RI) range. An open sensing channel is designed to facilitate the gold coating and accelerate the analyte infiltration. Results indicate that the sensitivity curve shows a nearly linear feature in two parts, and the maximal sensitivity is 4900 nm/RIU when the RI of the analyte is close to that of the background material of the fiber. Moreover, the sensitivities in low RI range and the signal to noise ratio can be improved by introducing air holes into the core center. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement