Design and test of a laser-based optical-fiber Bragg-grating accelerometer for seismic applications

We report on a proof-of-principle work aimed at the development of fast-response fiber-optic accelerometers for seismic monitoring. The system is based on a semiconductor diode-laser source that interrogates a newly devised two-dimensional inertial sensor suitable for measurement of horizontal ground accelerations. Plane acceleration components of the sensor's mass are detected by two fiber Bragg gratings anchored to its structure. Calibration and comparison with a commercial accelerometer are presented. A great potential, in terms of frequency response and sensitivity, is demonstrated in view of possible field applications in active seismic areas.