National Infrastructure for Dissemination of Precise Time and Ultra-stable Optical Frequency also Aiming to Connect Quantum Sources: CITAF

0575210 - ÚPT 2024 RIV US eng C - Konferenční příspěvek (zahraniční konf.)
Vojtěch, J. - Smotlacha, V. - Havliš, O. - Vohnout, R. - Špaček, M. - Novák, T. - Andriantsarazo, E. - Šlapák, M. - Altmannová, L. - Velc, R. - Pospíšil, P. - Kundrát, J. - Čížek, Martin - Hrabina, Jan - Řeřucha, Šimon - Pravdová, Lenka - Lazar, Josef - Číp, Ondřej - Kuna, Alexander - Roztočil, J.
National Infrastructure for Dissemination of Precise Time and Ultra-stable Optical Frequency also Aiming to Connect Quantum Sources: CITAF.
Proceedings of SPIE. In: Quantum Optics and Photon Counting 2023. Bellingham: SPIE, 2023 - (Procházka, I.; Sobolewski, R.), (2023), č. článku 1257003. Proceedings of SPIE, 12570. ISBN 978-1-5106-6260-5. ISSN 0277-786X.
[Quantum Optics and Photon Counting 2023. Prague (CZ), 26.04.2023-27.04.2023]
Institucionální podpora: RVO:68081731 ; RVO:67985882
Klíčová slova: precise time * coherent optical frequency * time metrology * infrastructure * optical amplification * optical fibre * White Rabbit
Obor OECD: Telecommunications; Telecommunications (URE-Y)
https://www.spiedigitallibrary.org/conference-proceedings-of-spie/12570/2665497/National-infrastructure-for-dissemination-of-precise-time-and-ultra-stable/10.1117/12.2665497.short

There has been an increased focus on precise time and frequency transmission dissemination at a national and international level recently. We would like to present the situation in the Czech Republic, our strategy, approach, and our experience with a non-commercial, cost-effective solution that utilizes shared optical networks. The presented solution provides accurate time and stable frequency at a lower operational cost, utilizing the shared spectrum of the CESNET3 network infrastructure. We are committed to future developments and upgrades that will include the next wavelength bands and geographic extensions. Additionally, we have implemented bidirectional dark channels on various wavebands, which utilize shared leased fibers and offer bidirectional compensation for fiber losses. However, operating precise time and frequency requires a single path with bidirectional amplification performed by optical amplifiers, which are sensitive to feedback from the fiber line induced by back-scattering, and reflections, and which can cause unwanted oscillations. We have addressed this issue by carefully solving the interference with parallel data transmissions. In summary, we have implemented a cost-effective solution for precise time and frequency dissemination in the Czech Republic, which utilizes shared optical networks. We are committed to future developments, and we are also part of a consortium that plans to realize a Pan-European network to offer time and frequency services to a broad range of users.
Trvalý link: https://hdl.handle.net/11104/0345044