DBR Fiber Laser Based High-Resolution Accelerometer Network

In this paper, we report a high-resolution and precision acceleration sensor network with potential large sensing capacity, which is based on distributed Bragg reflector fiber lasers. To start with, a transducer based on a T-shaped cantilever beam and an adjustable bearing is theoretically designed and experimentally employed to achieve high sensitivity and wideband frequency response. Second, the beat frequency interrogation system that utilizes super-heterodyne receiver and digital orthogonal phase identifying technology is developed to improve the resolution of the sensors. In addition, assisted with the wavelength/time division multiplexing technology, hundreds of sensing units could be potentially multiplexed in the prototype system. A proof-of-concept sensing network with three acceleration sensor units is established for experimental validation. The sensor network demonstrates a sensitivity of 1.16064 GHz/g with a flat frequency response region from 20 to 200 Hz, corresponding to a noise equivalent acceleration of 17.99 ng/√Hz at 90 Hz. In particular, the measurement precision of the prototype system has been calibrated as high as 1.305 μg. The proposed acceleration sensor network could benefit potential applications in smart unmanned platforms and seismic monitoring.