Simultaneous measurement of temperature and strain distribution by optical time-domain analysis of Brillouin dynamic grating

Discriminative measurements of strain and temperature distribution are demonstrated based on optical time-domain analysis of Brillouin dynamic grating (BDG) in a polarization-maintaining fiber. The local information of the Brillouin frequency and the BDG frequency are acquired with a 1.2 m spatial resolution, and analyzed together to provide the distribution map of temperature and strain variation with the accuracies of ±1 K and ±20 μs, respectively.