Optical Fiber Surface Plasmon Resonance Sensor Based on the Gold-Coated Hollow Fiber Structure for the Detection of Liquid With High Refractive Index

Abstract

A hollow fiber (HF) surface plasmon resonance (SPR) sensor based on the gold-coated HF structure for the detection of liquid with high refractive index has been presented experimentally for the first time. The designed sensors with different gold layer thicknesses are fabricated by the liquid phase deposition method. The performances of the fabricated sensors, including sensitivity and figure of merit, are analyzed with the measured transmission spectra. The experimental results show that the proposed sensor with a thicker gold layer exhibits the sensitivity and the corresponding figure of merit up to 8945 nm/RIU and 92 RIU <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> , respectively, which is much higher than that of the silver-coated HF SPR sensor reported previously. Considering the extraordinary chemical stability and durability of gold, the presented sensor has large potential in biological and chemical applications. Moreover, the chemical method of coating smooth gold film in the hollow core of HF presented in this work is simple and cost-effective. It can be employed easily in the fabrication of other kinds of microstructured optical fiber devices coated with gold film and promote the experimental realization of them.