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Journal of Optical Communications and Networking

Single-photon time-of-flight measurements for benchmarking time transfer in quantum networks

Dongxing He, Paulina S. Kuo, Ya-Shian Li-Baboud, Anouar Rahmouni, Matthew D. Shaw, Boris A. Korzh, Thomas Gerrits

Published Nov 14, 2025• 0 citations
Publisher

Abstract

We developed a single-photon time-of-flight measurement method to benchmark fiber-path-delay. The results suggest that augmenting existing optical two-way time and frequency transfer protocols could enhance the timing precision to sub-10 ps for metropolitan-scale quantum networks.
DOI
10.1364/cleo_at.2026.jtu.181

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The practical demonstration of an optical two-way time transfer based on single photon signal level has been completed. This approach enables to reach extreme timing stabilities and minimal systematic errors using existing electrooptic technologies. The crucial condition to almost eliminate systematic errors and to reach picosecond time transfer accuracy over free space communication channel is the maximum symmetry in experimental setup. In our indoor experiment we have achieved sub-picosecond precison and 3 ps accuracy. The entire system is compact and relatively simple.