He Yabai, Orr Brian J, Baldwin Kenneth G H, Wouters Michael J, Luiten Andre N, Aben Guido, Warrington R Bruce
MQ Photonics Research Centre, Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109, Australia.
Opt Express. 2013 Aug 12;21(16):18754-64. doi: 10.1364/OE.21.018754.
We demonstrate long-distance (≥100-km) synchronization of the phase of a radio-frequency reference over an optical-fiber network without needing to actively stabilize the optical path length. Frequency mixing is used to achieve passive phase-conjugate cancellation of fiber-length fluctuations, ensuring that the phase difference between the reference and synchronized oscillators is independent of the link length. The fractional radio-frequency-transfer stability through a 100-km "real-world" urban optical-fiber network is 6 × 10(-17) with an averaging time of 10(4) s. Our compensation technique is robust, providing long-term stability superior to that of a hydrogen maser. By combining our technique with the short-term stability provided by a remote, high-quality quartz oscillator, this system is potentially applicable to transcontinental optical-fiber time and frequency dissemination where the optical round-trip propagation time is significant.
我们展示了在无需主动稳定光路长度的情况下，通过光纤网络实现射频参考相位的长距离（≥100公里）同步。利用频率混频实现光纤长度波动的被动相位共轭抵消，确保参考振荡器与同步振荡器之间的相位差与链路长度无关。通过100公里“真实世界”城市光纤网络的分数射频传输稳定性为6×10^(-17)，平均时间为10^4秒。我们的补偿技术很稳健，提供的长期稳定性优于氢脉泽。通过将我们的技术与远程高质量石英振荡器提供的短期稳定性相结合，该系统有可能应用于光往返传播时间显著的跨大陆光纤时间和频率传播。
