IEEE Trans Ultrason Ferroelectr Freq Control. 2018 Jun;65(6):1001-1006. doi: 10.1109/TUFFC.2018.2833389.
Coherent optical fiber links recently demonstrate their ability to compare the most advanced optical clocks over a continental scale. The outstanding performances of the optical clocks are stimulating the community to build much more stable time scales, and to develop the means to compare them. Optical fiber link is one solution that needs to be explored. Here, we are investigating a new method to transfer time based on an optical demodulation of a phase step imprint onto the optical carrier. We show the implementation of a proof-of-principle experiment over 86-km urban fiber, and report time interval transfer stability of 1 pulse per second signal with sub-ps resolution from 10 s to one day of measurement time. Prospects for future development and implementation in active telecommunication networks, not only regarding performance but also compatibility, conclude this paper.
相干光纤链路最近展示了其在大陆尺度上比较最先进光学时钟的能力。光学时钟的出色性能激发了业界构建更稳定的时频基准的热情，并开发了对它们进行比较的手段。光纤链路就是需要探索的解决方案之一。在这里，我们研究了一种基于光载波上相位阶跃印记的光解调来传递时间的新方法。我们展示了在 86km 城市光纤上进行的原理验证实验的实现，并报告了在 10s 至 1 天的测量时间内，以亚皮秒分辨率对每秒 1 个脉冲的信号进行时间间隔传递稳定性的实验结果。本文最后还讨论了未来在有源光通信网络中的发展和实现的前景，不仅涉及性能，还涉及兼容性。
