Brillouin characterization of slimmed polymer optical fibers for strain sensing with extremely wide dynamic range.

To date, most distributed Brillouin sensors for structural health monitoring have employed glass optical fibers as sensing fibers, but they are inherently fragile and cannot withstand strains of >3%. This means that the maximal detectable strain of glass-fiber-based Brillouin sensors was ~3%, which is far from being sufficient for monitoring the possible distortion caused by big earthquakes. To extend this strain dynamic range, polymer optical fibers (POFs) have been used as sensing fibers.