Method to measure the second-order birefringence vector distribution along optical fibers based on high-speed polarization optical time domain reflectometry

Based on a high-speed polarization optical domain reflectometry, an innovative method to measure the second-order birefringence vector distribution along optical fibers was proposed and implemented in this paper. Some interesting data were obtained along a 1 km long single mode fiber by only one detection. The second-order birefringence magnitude distribution curve can reflect both magnitude and direction change information of the first-order birefringence, and it was more stable (except the catastrophe points) than that of the first-order. The larger variable range of the second-order birefringence magnitude may provide a higher sensitivity than the first-order for birefringence-based distributed sensors.