High-Spatial-Resolution Time-Domain Simultaneous Strain and Temperature Sensor Using Brillouin Scattering and Birefringence in a Polarization-Maintaining Fiber

We report on a high-spatial-resolution simultaneous strain and temperature measurement in time domain through measuring Brillouin frequency shift (BFS) and birefringence-induced frequency shift (BireFS) in a polarization-maintaining fiber. High-spatial-resolution BFS and BireFS measurement are obtained through differential pulsewidth pair Brillouin optical time-domain analysis and a local Brillouin grating, respectively. Simultaneous strain and temperature measurement with a spatial resolution of 20 cm is demonstrated in a 6-m Panda fiber. The temperature and strain accuracy is 0.4°C and 9 με, and their range can be up to 700°C and 14 mε, respectively.