Phase-Noise-Compensated OFDR Realized Using Hardware-Adaptive Algorithm for Real-Time Processing

A hardware-adaptive algorithm is proposed for phase-noise-compensated optical frequency domain reflectometry (PNC-OFDR) and the corresponding hardware system is designed to realize the real-time processing. The system not only keeps a high measurement performance with spatial resolution and measurement range of traditional PNC-OFDR, but also improves the processing efficiency, which was the main drawback in traditional PNC-OFDR. In the proof-of-concept experiment, a 7-cm spatial resolution is achieved over 100-km fiber link, which is much beyond the laser coherence length. By theoretical analysis, even at the “worst compensation point,” the signal-to-noise ratio is almost 40 dB. In the hardware-processing based system, a 7-cm spatial resolution is achieved over 37.5-km fiber link, in which the limited range is restricted by the register capacity available in the hardware we used. We believe the system is suitable for practical applications because of the real-time processing capability.