Measurement of large-strain dependence of optical propagation loss in perfluorinated polymer fibers for use in seismic diagnosis

Brillouin scattering in perfluorinated graded-index (PFGI-) polymer optical fibers (POFs) has been extensively studied for structural health monitoring, including seismic diagnosis. Here, we measure the propagation loss of PFGI-POFs at telecom wavelengths as a function of large applied strain (up to 100%) at three optical powers and as a function of strain rate at a constant optical power. The strain dependence of the propagation loss in PFGI-POFs is found to be independent of the incident power (<27 dBm) and the strain rate (<500%s−1), indicating that PFGI-POF-based Brillouin sensors are potentially applicable to actual seismic monitoring.