Distributed optical fiber sensing assited by optical communication techniques

The development of optical fiber technology has facilitated the technological innovation in optical fiber communication and sensing systems over the past decades. Among all the fiber sensing technologies, distributed optical fiber sensing (DOFS) has attracted great research interests and been extensively investigated. In optical fiber communication systems, optical parameters such as intensity, phase, polarization, or frequency are modulated to realize data transmission, while for DOFS they are employed to measure the distributed physical variance along the sensing fiber. Due to the similarities shared by optical fiber communication systems and DOFS systems, optical communication techniques, including coherent detection, polarization diversity and multicarrier signaling have been widely used in the DOFS to improve the sensing performance. In this paper, principles of coherent detection, polarization diversity and multicarrier signaling are introduced and their corresponding applications in Brillouin optical time domain analyzer and phase sensitive optical time domain reflectometry are reviewed. The proposed novel unidirectional forward transmission based DOFS is also presented.