Refractive Index and Temperature Sensing System With High Sensitivity and Large Measurement Range Using an Optical Fiber
Zhigang Gao, Yuhui Feng, Hailiang Chen, Qiang Chen, Yuxin Li, Mengwei Zhang
Abstract
In this article, a temperature and refractive index sensing probe based on a photonic crystal fiber (PCF) with a silver film coating is proposed. We suggested a simple method for coating silver films, and a silver film was coated on the periphery of the PCF that solves the previous difficulties of coating metal film inside the air holes or polishing a flat surface. The sensing probe has achieved dual-parameter sensing of refractive index and temperature by employing polydimethylsiloxane (PDMS) as the temperature-sensitive material. The results of the experiment demonstrated that the wide measurement range and high sensitivity of the sensing probe. It has a refractive index sensitivity of 3341.65 nm/unit of refractive index (RIU) in the range of 1.333–1.3953 and a temperature sensitivity of 2.02 nm/°C in the range of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$50-100\,\,^{\circ }\text{C}$ </tex-math></inline-formula> . The features of the suggested sensing probe, including its simple structure and ease of production, indicate the potential application in the field of biochemical sensing.