||Haiyun Xia, Mingjia Shangguan, Guoliang Shentu, Chong Wang, Jiawei Qiu, Mingyang Zhenge, Xiuping Xie, Xiankang Dou, Qiang Zhang, Jian-Wei Pan
||Opt. Commun., 381, 37 (2016)
||A direct-detection Brillouin optical time-domain reflectometry (BOTDR) using an up-conversion photon-counting detector and an all-fiber structure Fabry–Perot scanning interferometer is demonstrated with shot-noise limited performance. Taking advantage of ultra-low noise equivalent power of the up-conversion photon-counting detector and high spectral resolution of the interferometer, the Brillouin spectra along a polarization maintaining fiber (PMF) are analyzed in the optical frequency domain directly. In contrast with heterodyne BOTDR, photon-counting BOTDR has better EM compatibility and faster speed in data processing. In experiments, using peak input power of 20 dBm, temperature profile along a 9 km PMF is retrieved according to the Brillouin shifts, with spatial/temporal resolution of 2 m/15 s. The precision is 0.7 °C at the leading end and 1.2 °C at the trailing end.