Optical-Fiber Accelerometer Array: Nano-g Infrasonic Operation in a Passive 100 km Loop

In this paper, an all-optical accelerometer array system is presented, ideally suited for permanent seismic seabed arrays and passive surveillance. A directly measured accelerometer resolution of better than 60 ng/root Hz (-145 dB reg/root Hz) down to 10 Hz is achieved for all channels in a completely passive 100 km fiber loop. The detection bandwidth is chosen to be from 10 to 300 Hz, with a closed-loop dynamic range of 120 dB. The crosstalk between channels spaced by 100 GHz is better than -64 dB.