Simultaneous strain and temperature measurement in PM fibers using Brillouin frequency, power, and bandwidth

The strain and temperature dependence of the Brillouin gain/loss spectrum has been studied in terms of Brillouin frequency, power and bandwidth for panda, bow-tie and tiger polarization maintaining (PM) fibers using our Brillouin gain/loss based distributed sensor system for the first time. The PM fibers are stressed at various temperature to measure the power, bandwidth and Brillouin frequency coefficients at the spatial resolution of 20 cm. Using our measured coefficients with various combinations Brillouin power and bandwidth and Brillouin frequency, we realized three groups of simultaneous temperature and strain sensing, for Brillouin frequency combined with bandwidth, strain/temperature resolutions are 39με/2°C (panda), 126με/3°C (bow-tie), 598με/16°C (tiger); for the Brillouin frequency combined with power, strain/temperature resolutions are 153με/8°C (panda), 237με/4°C (bow-tie); for the bandwidth combined with power, strain/temperature resolutions are 135με/38°C (panda), 195με/38°C (bow-tie).