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Coherent optical link over hundreds of metres and hundreds of terahertz with subfemtosecond timing jitter



Ian R. Coddington, William C. Swann, Luca Lorini, J. C. Bergquist, K Feder, Y. Le Coq, Jeffrey W. Nicholson, C. W. Oates, Qudsia Quraishi, Paul S. Westbrook, Scott Diddams, Nathan R. Newbury


Recent developments in stabilized lasers have resulted in ultrastable optical oscillators with spectral purities below 1 Hz refs 1-6. These oscillators are not transportable at present and operate at a single frequency. To realize their full potential, a highly-coherent, frequency-diverse fiber-optic network is needed to faithfully transfer the optical signals to remote sites and to different optical frequencies. Here we demonstrate such a coherent network composed of erbium fibre and Ti:sapphire laser-based, optical frequency combs7-9, stabilized optical-fibre links4,10 and cavity-stabilized lasers4-6. We coherently transmit an optical carrier over 750 m of optical fibre with conversions to wavelengths of 657, 767, 1,126 and 1,535 nm, an overall timing jitter of 590 attoseconds, and a frequency instability of 12 mHz for the 195 THz carrier in 1 s and 250 υHz in 1,000 s. This first remote synchronization of two frequency combs also demonstrates a factor of 30 improvement in the relative stability of fibre frequency combs11,12.
Nature Photonics


coherent network, frequency comb, frequency transfer


Coddington, I. , Swann, W. , Lorini, L. , Bergquist, J. , Feder, K. , Le Coq, Y. , Nicholson, J. , Oates, C. , Quraishi, Q. , Westbrook, P. , Diddams, S. and Newbury, N. (2007), Coherent optical link over hundreds of metres and hundreds of terahertz with subfemtosecond timing jitter, Nature Photonics, [online], (Accessed April 21, 2024)
Created April 30, 2007, Updated October 12, 2021