Few-mode fiber multi-parameter sensor with distributed temperature and strain discrimination.

We propose a unique few-mode fiber (FMF)-based multi-parameter optical-fiber sensor for distributed measurement of temperature and strain. We launch a pump and a probe signal through specific linearly polarized modes into a FMF, and monitor the Brillouin frequency shift (BFS) in each mode. By analyzing the temperature and strain coefficients of the BFS of the two lowest order (LP(01), LP(11)) modes, discrimination of temperature and strain are successfully demonstrated, with an accuracy of 1.2°C and 21.9  με.