Simultaneous remote transfer of accurate timing and optical frequency   over a public fiber network
  In this work we demonstrate for the first time that it is possible to transfer simultaneously an ultra-stable optical frequency and a precise and accurate timing over 540 km using a public telecommunication optical fiber networks with Internet data. The optical phase is used to carry both the frequency information and the timestamps by modulating a very narrow optical carrier at 1.55 $\mu$m with spread spectrum signals using two-way satellite time transfer modems. The results in term of absolute time accuracy (250 ps) and long-term timing stability (20 ps) well outperform the conventional Global Navigation Satellite System or geostationary transfer methods. 
Olivier Lopez (LPL), Amale Kanj (SYRTE), Paul-Eric Pottie (SYRTE),   Giovanni D. Rovera (SYRTE), Joseph Achkar (SYRTE), Chri...
physics.optics physics.ins-det quant-ph