Fiber optic pressure sensor based on polarization-maintaining photonic crystal fiber for downhole application

We experimentally demonstrate a high pressure sensor based on a polarization-maintaining photonic crystal fiber (PMPCF) with Sagnac loop configuration for downhole application. The pressure sensitivity of the proposed sensor is 4.21 nm/MPa and 3.27 nm/MPa at ~1320 nm and ~1550 nm respectively. High pressure measurement up to 20 MPa has been achieved in our experiment. The sensor also shows reduced temperature sensitivity, making it an ideal candidate for pressure sensing in harsh environment.