Frequency transfer via a two-way optical phase comparison on a multiplexed fiber network.

We performed a two-way remote optical phase comparison on optical fiber. Two optical frequency signals were launched in opposite directions in an optical fiber and their phases were simultaneously measured at the other end. In this technique, the fiber noise is passively canceled, and we compared two optical frequencies at the ultimate 10(-21) stability level. The experiment was performed on a 47 km fiber that is part of the metropolitan network for Internet traffic. The technique relies on the synchronous measurement of the optical phases at the two ends of the link, which is here performed by digital electronics. This scheme offers some advantages with respect to active noise cancellation schemes, as the light travels only once in the fiber.

[1]  F. Levi,et al.  Electronics for the Pulsed Rubidium Clock: Design and Characterization , 2007, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[2]  Christian Chardonnet,et al.  Simultaneous remote transfer of accurate timing and optical frequency over a public fiber network , 2013 .

[3]  D. J. Richardson,et al.  Dissemination of an optical frequency comb over fiber with 3 × 10−18 fractional accuracy , 2012, Conference on Lasers and Electro-Optics.

[4]  R. B. Warrington,et al.  Stable radio-frequency transfer over optical fiber by phase-conjugate frequency mixing. , 2013, Optics express.

[5]  B. Wang,et al.  Precise and Continuous Time and Frequency Synchronisation at the 5×10-19 Accuracy Level , 2012, Scientific Reports.

[6]  G. Ascheid,et al.  Cycle Slips in Phase-Locked Loops: A Tutorial Survey , 1982, IEEE Trans. Commun..

[7]  Albin Czubla,et al.  Dissemination of time and RF frequency via a stabilized fibre optic link over a distance of 420 km , 2013 .

[8]  S. Nagano,et al.  Coherent microwave transfer over a 204-km telecom fiber link by a cascaded system , 2010, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[9]  M. Lours,et al.  High-resolution microwave frequency dissemination on an 86-km urban optical link , 2009, 0907.3500.

[10]  D. Wineland,et al.  Frequency comparison of two high-accuracy Al+ optical clocks. , 2009, Physical review letters.

[11]  Przemyslaw Krehlik,et al.  Frequency Transfer in Electronically Stabilized Fiber Optic Link Exploiting Bidirectional Optical Amplifiers , 2012, IEEE Transactions on Instrumentation and Measurement.

[12]  Davide Calonico,et al.  Planar-waveguide external cavity laser stabilization for an optical link with 10-19 frequency stability , 2011, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[13]  E. Rubiola,et al.  Phase Noise and Frequency Stability in Oscillators , 2008 .

[14]  A. Bauch,et al.  Time transfer through optical fibres over a distance of 73 km with an uncertainty below 100 ps , 2012, 1209.4467.

[15]  C Clivati,et al.  Large-area fiber-optic gyroscope on a multiplexed fiber network. , 2012, Optics letters.

[16]  Paul A. Williams,et al.  High-stability transfer of an optical frequency over long fiber-optic links , 2008 .

[17]  D. Wineland,et al.  Optical Clocks and Relativity , 2010, Science.

[18]  Christian Chardonnet,et al.  Cascaded multiplexed optical link on a telecommunication network for frequency dissemination. , 2010, Optics express.

[19]  Andrew G. Glen,et al.  APPL , 2001 .

[20]  D. Wineland,et al.  Frequency Ratio of Al+ and Hg+ Single-Ion Optical Clocks; Metrology at the 17th Decimal Place , 2008, Science.

[21]  R. Dach,et al.  Comparison between frequency standards in Europe and the USA at the 10−15 uncertainty level , 2006 .

[22]  T. Hänsch,et al.  A 920-Kilometer Optical Fiber Link for Frequency Metrology at the 19th Decimal Place , 2012, Science.