High resolution FBG sensor and its applications in Geophysics

A high-resolution FBG sensor is proposed for crust deformation observation and earthquake monitoring. A narrow-linewidth tunable fiber laser is used to interrogate the FBG. The wavelength shift of the FBGs due to seismic signal is measured by swept optical suppressed carrier single sideband (SSB-SC) interrogation technique with a reference FBG. The self-noise level is tested to be lower than NHNM. A crust deformation observation experiment is carried out in a seismic monitoring station. The results of clear tidal signals and seismic signals are given.