Temperature and Strain Independent Modal Interferometric Torsion Sensor Using Photonic Crystal Fiber

An all-fiber modal interferometric torsion sensor based on simple splicing configuration is presented wherein a photonic crystal fiber is spliced in between multimode fiber and single mode fiber. Appreciable torsion sensitivity of ~79.83 pm/° is obtained in the long dynamic range of 180°. It is also found that there is no effect of strain and temperature on torsion sensitivity in the range of 0-4500 με and 30-200°C, respectively, leading to zero cross-sensitivity of torsion with strain and temperature.