The T-REFIMEVE project, “Shared Time-Frequency Service via Optical Fiber,” aims to distribute ultra-stable time and frequency signals to around 30 French laboratories with no performance degradation. These signals are generated at LTE (Paris Observatory) and transmitted via the RENATER academic network. While the earlier REFIMEVE+ project focused solely on optical frequency transfer, T-REFIMEVE also distributes time signals, enabling precise event synchronization. In 2021, it was granted the status of a national research infrastructure under the name REFIMEVE. This new projet dramatically increases the range of potential users and scientific applications, including spectroscopy, astrophysics, high-energy physics, fundamental physics experiments, particle accelerators, geosciences, quantum communications, and high-speed network management.
The distributed signals originate from cold atom clocks, among the world’s most precise, providing frequency and timing data with 17 significant digits. These signals are transported with full fidelity, meaning partner labs can operate as if they had LTE’s atomic clocks locally. Currently, 30 laboratories and the German (PTB), UK (NPL), and Italian (INRIM) metrology institutes are connected. The project has already enabled comparisons of Europe’s best atomic clocks and precision measurements at the connected sites. Network expansion and pilot White Rabbit deployments are underway, further broadening REFIMEVE’s applications.
