Bending-Loss-Resistant Distributed Temperature and Strain Discriminative Brillouin Sensor Based on 98 mol% Germania-Doped Few-Mode Fiber

Temperature-strain cross-sensitivity and bending-induced optical loss are two major limitations that challenge the in-situ application of distributed optical fiber sensors. Researchers have attempted to solve these two issues but seldom can overcome both. This paper proposes a novel bending-loss-resistant distributed temperature and strain discriminative sensor that is based on a 98 mol% germania-doped few-mode fiber and a standard Brillouin optical time-domain analysis setup. In a proof-of-concept demonstration, distributed temperature and strain discriminative measurements were conducted under a bending radius of 0.6 cm, where the maximum temperature and strain deviation were 2.78 °C and 33.2 {\rm{\mu }}\varepsilon, respectively.