Fiber-Longitudinal Anomaly Position Identification Over Multi-Span Transmission Link Out of Receiver-end Signals

We have developed a fiber-longitudinal monitor that visualizes distance-wise optical power throughout the entire multi-span link by using the signal waveform obtained by a coherent receiver placed at the receiver-end. This is an in-situ monitor that estimates power profile along the link-longitudinal axis from its incoming signal by employing digital post-processing of coherent receiver data. We demonstrate through experiments that our method can simultaneously visualize and localize multiple power attenuation anomalies over fiber transmission links. This data processing-based monitoring by digital coherent receiver will be a key element in future autonomous optical networks driven by rich information on physical-layer.