Potential applicability of Brillouin scattering in partially chlorinated plastic optical fibers to high-precision temperature sensing

Compared with other plastic optical fibers (POFs), partially cholorinated graded-index (PCGI-) POFs with high thermal stability are a good candidate for the sensing heads of Brillouin-based distributed temperature sensors. In this work, we estimate the Brillouin frequency shift (BFS) and its temperature dependence in a PCGI-POF using ultrasonic pulse-echo technique. At 1550 nm, the estimated BFS is ~4.43 GHz with its temperature coefficient of approximately -6.9 MHz/K. Its absolute value is even higher than that of perflurointated GI-POF, indicating that the Brillouin scattering in PCGI-POFs can be potentially applied to high-precision temperature sensing.