Stimulated Brillouin scattering in a tapered dual-core As2Se3-PMMA fiber for simultaneous temperature and strain sensing

Chalcogenide fibers are currently being used widely in nonlinear optical signal processing, as they exhibit ultrahigh nonlinearity. Here, we propose a sensor based on stimulated Brillouin scattering for simultaneous temperature and strain measurement in a dual-core tapered A s 2 S e 3 -polymethyl methacrylate fiber using a Brillouin optical time-domain analysis system. Different Brillouin frequency responses under temperature and strain variations and the separation of Brillouin frequency shifts (BFSs) in two principal polarization axes are demonstrated experimentally over a 50-cm-long tapered dual-core hybrid microfiber. The temperature coefficients are − 3.8272 M H z / ∘ C and − 3.3302 M H z / ∘ C , and the strain coefficients are − 0.06143 M H z / µ ε and − 0.03463 M H z / µ ε . Due to the different temperature and strain dependences of Brillouin frequency peaks in two polarizations, temperature and strain resolutions of 1°C and 33 µ ε are realized, respectively. Numerical simulations are also reported to account for the BFS difference in two polarization axes.