SI-traceable frequency dissemination at 1572.06 nm in a stabilized fiber network with ring topology

TL;DR

This paper demonstrates SI-traceable ultrastable optical frequency dissemination over a 456 km fiber network with ring topology in the L-band, effectively avoiding C-band telecommunication traffic and enabling precise remote frequency comparisons.

Contribution

It introduces a novel method for frequency dissemination in the L-band using ring topology, overcoming C-band channel limitations and ensuring compatibility with existing telecommunication traffic.

Findings

Achieved a link instability of 4.7×10⁻¹⁶ at 1 s and 3.8×10⁻¹⁹ at 2000 s.

Demonstrated SI-traceability of a laser in a remote lab.

Showed no interference with telecommunication data traffic.

Abstract

Frequency dissemination in phase-stabilized optical fiber networks for metrological frequency comparisons and precision measurements are promising candidates to overcome the limitations imposed by satellite techniques. However, network constraints restrict the availability of dedicated channels in the commonly-used C-band. Here, we demonstrate the dissemination of an SI-traceable ultrastable optical frequency in the L-band over a 456 km fiber network with ring topology, in which telecommunication data traffic occupies the full C-band. We characterize the optical phase noise and evaluate a link instability of $4.7\cdot 10^{-16}$ at 1 s and $3.8\cdot 10^{-19}$ at 2000 s integration time, and a link accuracy of $2\cdot 10^{-18}$, which is comparable to existing metrology networks in the C-band. We demonstrate the application of the disseminated frequency by establishing the SI-traceability of a laser in a remote laboratory. Finally, we show that our metrological frequency does not interfere with data traffic in the telecommunication channels. Our approach combines an unconventional spectral choice in the telecommunication L-band with established frequency-stabilization techniques, providing a novel, cost-effective solution for ultrastable frequency-comparison and dissemination, and may contribute to a foundation of a world-wide metrological network.