Metrological Fiber Network with a European Vocation +
Partners : 18 public labs, CNES, RENATER (NREN), IDIL (private company)…
REFIMEVE+ (REseau FIbré MEtrologique à Vocation Européenne+) is based on the technology developed by LPL and SYRTE for the ultra-stable frequency transfer over long-haul fibers on a public network. It was experimentally demonstrated on a test section from Villetaneuse (close to Paris) to Reims that the clock signal can be transmitted, throughout the Internet academic network RENATER over 540km, with a “reproducing” accuracy of 2×10-19 after one day measurement time. This performance relies on the precision measurement of the roundtrip time, which enables the compensation of the delay introduced by the fiber, and of course of its fluctuations. This result paves the way to clock comparison on a continental scale using clocks whose accuracy is of parts in 10–16, and targets the 10–17in a near future. REFIMEV+ has the potential to replace the GPS as the standard method for clock comparison, pushing precision and accuracy to the level required by modern optical clocks.
The project aims at broadcasting the standard optical frequency to 21 French labs, and gradually extend to other European Countries.
The broadcasting of absolute time is also under study.While the highest-level of precise and accurate frequency comes from SYRTE, FEMTO-ST will have the second largest set of oscillators and atomic frequency standard in France. This is thanks to the Oscillator IMP Equipex, and also for physical experiments that require accurate and stable frequency at both ends of the fiber. The large set of oscillators and standards makes FEMTO-ST a privileged collaborator of SYRTE and LPL for testing the system, and also for physical experiments that require accurate and stable frequency at two ends of the fiber.
While Oscillator IMP is specialized in the measurement of small fluctuations and noise, REFIMEVE+ aims to provide the highest absolute accuracy.
REFIMEVE+ key figures :
- Created in 2012
- Budget: 6.7 M€ over 8 years