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arXiv · 2404.09535

Dual-comb-enhanced microwave clock synchronization over commercial fiber

Ziyang Chen·Dongrui Yu·Ganbin Lu·Yufei Zhang·Song Yu·Bin Luo·Hong Guo
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Abstract

The large-scale clock network is the key ingredient to obtain high precision in many scenarios, from fundamental research to cutting-edge applications. The advantage of the time synchronization among microwave clocks is their cost, size, and accessibility. Here, we demonstrate a femtosecond-level time synchronization of microwave clocks through a commercial link of 205.86 km via dual-comb-enhanced optical two-way time transfer, which achieves a 6.23-fs residual time deviation between synchronized timescales at 1 s and an instability below 6E-18 at 10,000 s. Further, the high-precision time synchronization of microwave clocks significantly enhances the probe ability of subtle reciprocity changes of fiber to the sub-picosecond level. This work provides a path toward secure fiber time-frequency networks to support future microwave-clock-based precise timing and sensing systems.

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Ziyang Chen, Dongrui Yu, Ganbin Lu, Yufei Zhang, Song Yu, Bin Luo, Hong Guo. 2024-04-15. Dual-comb-enhanced microwave clock synchronization over commercial fiber. https://doi.org/10.1364/optica.530224

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