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arXiv:1108.2774 · Applied Physics Express

Direct Comparison of Distant Optical Lattice Clocks at the $10^{-16}$ Uncertainty

Atsushi Yamaguchi, Miho Fujieda, Motohiro Kumagai, Hidekazu Hachisu, Shigeo Nagano, Ying Li, Tetsuya Ido, Tetsushi Takano, Masao Takamoto, Hidetoshi Katori

Published Aug 4, 2011• 106 citations
arXivHTMLPDF

Abstract

Fiber-based remote comparison of 87 Sr lattice clocks in 24 km distant laboratories is demonstrated. The instability of the comparison reaches 5 × 10 -16 over an averaging time of 1000 s, which is two orders of magnitude shorter than that of conventional satellite links and is limited by the instabilities of the optical clocks. By correcting the systematic shifts that are predominated by the differential gravitational redshift, the residual fractional difference is found to be (1.0±7.3) × 10 -16 , confirming the coincidence between the two clocks. The accurate and speedy comparison of distant optical clocks paves the way for a future optical redefinition of the second.

DOI
10.1143/apex.4.082203

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Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Sep 8, 2011•1 citation
Direct Comparison of Distant Optical Lattice Clocks at the 10−1610^{-16}10−16 Uncertainty
Fiber-based remote comparison of 87 Sr lattice clocks in 24 km distant laboratories is demonstrated. The instability of the comparison reaches 5 × 10 -16 over an averaging time of 1000 s, which is two orders of magnitude shorter than that of conventional satellite links and is limited by the instabilities of the optical clocks. By correcting the systematic shifts that are predominated by the differential gravitational redshift, the residual fractional difference is found to be (1.0±7.3) × 10 -16 , confirming the coincidence between the two clocks. The accurate and speedy comparison of distant optical clocks paves the way for a future optical redefinition of the second.
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