Highly stable radio-frequency dissemination with suppressed residual phase noise based on a wavelength-selective optical reflecting structure

In this paper, we propose an approach for highly stable radio-frequency (RF) dissemination with suppressed residual phase noise (RPN) based on a wavelength-selective optical reflecting (WSOR) structure. In the proposed system, both the transmitted RF signal and a low-frequency probe signal are jointly fed into a high-speed dual-drive Mach-Zehnder modulator. The generated intensity-modulated optical signal is transmitted from the local site to the remote site over an optical fiber link. At the remote site, the received optical signal is split into two branches, where one is directed to the WSOR structure, which reflects only the optical components corresponding to the probe frequency, while the other is sent to a high-speed photodetector for recovering the transmitted RF signal. This configuration effectively suppresses RPN induced by Rayleigh backscattering. Experimental validation demonstrates an RPN suppression ratio of 13.8 dB at 18 GHz. Moreover, RF signals with tunable frequencies from 14 GHz to 18 GHz are successfully disseminated over a 10-km fiber link. The root-mean-square delay jitter measured over one hour remains below 0.214 ps, confirming the system's exceptional stability. The proposed scheme offers distinct advantages, including low RPN, high stability, and broad transmission bandwidth, making it highly suitable for distributed systems demanding stringent coherence and timing stability.