In-Fiber Twist Sensor Based on a Fiber Bragg Grating With 81$^{\circ}$ Tilted Structure

Abstract

We report a strong polarization dependent coupling behavior of fiber Bragg gratings with excessively tilted structures up to 81deg. This unique property has been utilized to implement a novel twist sensor, showing high torsion sensitivity. The twist induced light coupling interchange between the two birefringence modes makes it possible to interrogate such a sensor using low-cost intensity demodulation technique