Distributed Acoustic Sensing Based on Multi-Core Fiber

In this study, we use multiple independent parallel spatial channels in multi -core fibers to achieve spatial diversity in solving the signal fading and limited signal-to-noise ratio of distributed fiber acoustic sensing systems based on traditional single-mode fibers. We use the fan -in and fan -out modules for independent transmission and centralized reception of signals in four cores of the multi-core fiber, and multiple signals can be aggregated effectively using a coherent aggregation method. The experimental results show a well -reconstructed external disturbance signal, suppressed signal fading, and reduced noise floor by 5.2 dB compared with that of the optimized single-mode fiber system. The sensor exhibits high-level performance: lowest noise floor of 85 dB and bandwidth of 10 kHz.