31 January 2020
French physicists at Systèmes de référence temps-espace (CNRS/Observatoire de Paris/UPMC, associated to LNE) and at Laboratoire de physique des lasers (CNRS/Université Paris 13) and German physicists at Physikalisch-Technische Bundesanstalt established a fully optical connection between France and Germany with a crucial support of RENATER: optical frequencies can now be compared accurately through a 1400 km optical fiber link, connecting with unprecedented resolution the national metrology institutes LNE-SYRTE and PTB, where the most accurate Sr optical clocks in Europe are operated. The new link is used to compare two optical lattice clocks distant by a geographical distance of 700 km with an unrivaled fractional uncertainty of 5 × 10-17. The absolute frequency of the two optical clocks are found in agreement within their uncertainty budgets. This comparison is 20 times more precise than what was achievable so far by using GPS, and the measurement is 10 000 faster for the same resolution. It paves the way to future applications in fundamental physics, astrophysics and geoscience.
Read more :
Download a short notice :
Read the article on Nature Communication’s website
Press alert (in French)
Visit REFIMEVE+ website
Visit the Optical Frequency Group webpage
Attached documents
- french_syrte_webnews.pdf (PDF – 559.2 kb)