Single-End-Access Correlation-Domain Distributed Fiber-Optic Sensor Based on Stimulated Brillouin Scattering

We propose a single-end-access correlation-domain distributed fiber-optic sensor based on stimulated Brillouin scattering (SBS) in a polarization-maintaining optical fiber (PMF). Frequency-modulated pump and probe waves are launched into the same end of the PMF with orthogonal polarization states. Assisted by a polarization beam splitter and a polarization-maintaining isolator installed at the other end of the PMF, SBS interaction between the reflected probe wave and the forward pump wave is exclusively localized within the PMF. Unlike the previously-reported method based on placing a reflector at the far end of the fiber (Song , 2008), in which the measurement range is shortened to a half of the nominal value determined by the frequency modulation, as given in the work by Hotate and Hasegawa (2000), our new method maintains the range as the nominal value. Distributed sensing of temperature or strain is experimentally demonstrated with the measurement range/the spatial resolution of 200 m/16 cm, 56 m/5 cm, or 5.6 m/5 mm, respectively.