Real-Time Multipath Fusion φ-OTDR System Based on FPGA

Phase-sensitive optical time domain reflectometry (φ-OTDR), renowned for its ability to demodulate the phase of interference information on sensing fibers, finds widespread application across various fields, owing to its extensive sensing distance and high sensitivity. In this paper, we introduce a realtime φ-OTDR system implemented on a Field Programmable Gate Array (FPGA). This system achieves coherent fading suppression by fusing information from different polarization states. Experimental results demonstrate the system's capability to reconstruct the phase of the disturbance signal effectively, suppress signal fading, and enhance the Signal-to-Noise Ratio (SNR) by 3dB compared to the optimized single-path system.