Open-cavity Fabry-Perot interferometer pressure and temperature fiber sensor based on photonic crystal fiber

摘要

We propose and demonstrate a cascaded-cavities Fabry-Perot interferometer (FPI) for simultaneous measurement of pressure and temperature based on photonic crystal fiber. The sensor is composed of cascaded air-cavity and silica-cavity. The air-cavity and silica-cavity are both sensitive to temperature and pressure because of the thermo-optic coefficient and Young's modulus. We can obtain the pressure sensitivity and the temperature sensitivity of each cavity by band-pass filtering of the sensor spectrum in the frequency domain. Therefore the proposed sensor can simultaneously measure the pressure and temperature without pressure-temperature cross-talk. The proposed sensor has a compact and all-fiber structure, while the fabrication process of the cascaded FPI sensor is easy with just a few steps of splicing and cleaving.