Highly Sensitive FBG-FP sensor for Simultaneous Measurement of Humidity and Temperature

A fiber Fabry–Perot interferometer (FPI) with the ability of temperature compensation for humidity measurement based on a polyvinyl alcohol (PVA) film is proposed and experimentally demonstrate. By measuring FP cavity gap length directly through the cross-correlation algorithm, relative humidity (RH) and temperature response sensitivity can reach up to 0.061 μm/(1%) and ~10 nm/°C, respectively.