Eur. Phys. J. D 48, 35-41 (2008)
https://doi.org/10.1140/epjd/e2008-00059-5

86-km optical link with a resolution of 2 × 10^-18 for RF frequency transfer

¹ Laboratoire de Physique des Lasers, UMR 7538 CNRS, Université Paris 13, 99 avenue J.-B. Clément, 93430 Villetaneuse, France
² LNE-SYRTE, UMR 8630 CNRS, Observatoire de Paris, 61 avenue de l'Observatoire, 75014 Paris, France

Corresponding author: ^a amy@univ-paris13.fr

Received: 6 November 2007
Revised: 22 February 2008
Published online: 4 April 2008

Abstract

RF frequency transfer over an urban 86 km fibre has been demonstrated with a resolution of 2×10^-18 at one day measuring time using an optical compensator. This result is obtained with a reference carrier frequency of 1 GHz, and a rapid scrambling of the polarisation state of the input light in order to reduce the sensitivity to the polarisation mode dispersion in the fibre. The limitation due to the fibre chromatic dispersion associated with the laser frequency fluctuations is highlighted and analyzed. A preliminary test of an extended compensated link over 186 km using optical amplifiers gives a resolution below 10^-17 at 1 day.