Recent progress in ultra-long distributed fiber-optic sensing

Distributed fiber-optic sensing (DFOS) is one of the most important parts in the fiber-optic sensing field, due to the following advantages:1) there is no need to manufacture sensors on the fiber; 2) fibers are able to realize transmission and detection simultaneously; 3) long-distance/large-scale sensing and networking can be accomplished prospectively; 4) the spatial distribution and measurement information of physical parameters such as temperature, strain and vibration, can be obtained continuously along the fiber link, and the number of sensing points on a single fiber can be up to several tens of thousands. Due to the above tremendous superiority, DFOS has found wide application prospects, including perimeter security, oil/gas exploration, electrical facilities and structure monitoring, etc. This paper overviews recent progress in ultra-long distributed fiber-optic static (Brillouin optical time-domain analyzer) and dynamic (phase-sensitive optical time-domain reflectometer) sensing at Key Laboratory of Optical Fiber Sensing and Communications, UESTC. This paper summarizes our work on both basic and application studies.