High-accuracy active phase stabilization system based on microwave photonic phase-derived ranging

A phase-stable transmission system is proposed based on high accuracy and fast measurement of optical transfer delay(OTD). Only 4 frequency points are required to solve the optical transfer delay, which can greatly reduce the time spent on continuous multi-frequency sweeping during the phase-derived process to enhance the robustness of an active phase stabilization system. The system achieved an OTD measurement accuracy of ±0.08 ps in the proof-of-concept experiment. We also measured the link delay stability of the two 2 km optical fiber links with and without phase stabilization for 2 hours. During the measurement, the fluctuation between the phase-stable link delay and the set delay was within ±0.18 ps, while the delay difference without phase stabilization was over 200 ps.