Experimental realization of an optical second with strontium lattice clocks

Targat, Rodolphe Le; Lorini, L.; Coq, Yann Le; Zawada, M.; Guéna, Jocelyne; Abgrall, M.; Gurov, Mikhail; Rosenbusch, P.; Rovera, Daniele; Nagórny, Bartłomiej; Gartman, R.; Westergaard, Philip G.; Tobar, Michael E.; Lours, M.; Santarelli, Giorgio; Clairon, A.; Bize, S.; Laurent, Ph.; Lemonde, P.; Lodewyck, Jérôme

doi:10.1038/ncomms3109

Cited by 231 publications

(271 citation statements)

References 50 publications

Supporting

Mentioning

249

Contrasting

Unclassified

Order By: Relevance

“…4), but they were soon limited by the cesium accuracy. LNE-SYRTE published the first comparison between two local OLCs that confirm the accuracy budget of the clocks better than the accuracy of the cesium fountains, involving two Sr clocks with a frequency difference smaller than their combined accuracy budgets of 1.5 × 10 −16 [23]. This resolution is obtained after less than one hour of integration.…”

Section: Optical Lattice Clocksmentioning

confidence: 98%

“…It has a recommended uncertainty of 1 × 10 −15 . More recently, LNE-SYRTE reported a measurement of the 87 Sr clock transition with an uncertainty of 3.1×10 −16 limited by the accuracy of atomic fountains [23]. This is the most accurate absolute measurement to date of any atomic frequency.…”

Section: Advanced Timekeepingmentioning

confidence: 99%

“…This includes the above Rb/Cs result (see sect. 4), optical frequency measurements of H(1S-2S) [45], Yb + [46], Hg + [47], Dy [48] and Sr (see above, and [23] and references therein) against Cs, and the optical-to-optical ion clock frequency ratio Al + /Hg + [49]. The fit yields independent constraints for the three constants given in the first row of the Table in fig.…”

Section: Fundamental Physics Testsmentioning

confidence: 99%

“…Proposed in 2001 [21][22], OLCs made tremendous progress in the last decade. OLCs have demonstrated unprecedented frequency stabilities of a few 10 −16 / √ τ and a record accuracy below 10 −17 [1], overcoming the best ion clocks [1,[23][24][25][26]. With current improvement in laser stabilization, OLCs are expected to reach a QPN limited stability on the order of 10 −17 / √ τ within a few years, thus enabling even better characterization of systematic effects.…”

Section: Optical Lattice Clocksmentioning

confidence: 99%

See 3 more Smart Citations

Atomic fountains and optical clocks at SYRTE: Status and perspectives

Abgrall

Chupin

Sarlo

et al. 2015

Comptes Rendus. Physique

View full text Add to dashboard Cite

In this article, we report on the work done with the LNE-SYRTE atomic clock ensemble during the last 10 years. We cover progress made in atomic fountains and in their application to timekeeping. We also cover the development of optical lattice clocks based on strontium and on mercury. We report on tests of fundamental physical laws made with these highly accurate atomic clocks. We also report on work relevant to a future possible redefinition of the SI second. IntroductionResearch on highly accurate atomic frequency standards and their applications is making fast and steady progress. The quest for ever increased accuracy is advancing hand in hand with advances in quantum physics, with better understanding and manipulation of atomic systems, with exploration of fundamental laws of nature and with the development of important services and infrastructures for science and society. The quest for increased accuracy is also a powerful incentive to innovation in such areas as lasers, laser stabilization, low noise electronics, stable oscillators, low noise detection of optical signals, fiber devices and cold-atom based instrumentation for ground or space applications. Finally, in addition to enhancing existing applications, improved accuracy leads to new applications.This article focuses on key achievements and trends of the last 10 years. Over this period of time, the first generation of laser-cooled standards, using the atomic fountain geometry, reached maturity and had large impact on international timekeeping. The typical accuracy of these frequency standards, 2 parts in 10 16 , is now permanently accessible both locally and globally. At the same time, a new generation of optical clocks showed tremendous and steady improvement, gaining more than two orders of magnitude in a decade. To date, an accuracy of 6.4 × 10 −18 [1] was reported. Similarly, major improvements occurred in many other aspects of optical frequency metrology, notably in optical frequency combs and optical fiber links.In this article, we will report on developments of the LNE-SYRTE atomic clock ensemble since our 2004 report in the Special Issue of the Comptes Rendus de l'Académie des sciences on Fundamental Metrology [2]. This work exemplifies many of the above mentioned features of research on highly accurate atomic frequency standards. We will focus on frequency standards and their impact on timescales and timekeeping, on clock comparisons, including optical-to-microwave comparisons with combs, and their applications. Several

show abstract

Section: Optical Lattice Clocksmentioning

confidence: 98%

Section: Advanced Timekeepingmentioning

confidence: 99%

Section: Fundamental Physics Testsmentioning

confidence: 99%

Section: Optical Lattice Clocksmentioning

confidence: 99%

See 2 more Smart Citations

Atomic fountains and optical clocks at SYRTE: Status and perspectives

Abgrall

Chupin

Sarlo

et al. 2015

Comptes Rendus. Physique

View full text Add to dashboard Cite

show abstract

“…Although a typical Er:fiber comb uses nonlinear polarization rotation (NPR) to acquire mode-locking with excellent noise performance, [9][10][11][12][13] the operational condition for such NPR-based Er:fiber oscillators can be sensitive to environmental conditions. For practical applications, such as the longterm operation of clocks to generate the optical second 14) and field and space applications, the all-polarization-maintaining (PM) architecture is preferred. 15,16) However, such architecture has shown relatively large phase noise.…”

mentioning

confidence: 99%

All-polarization-maintaining, single-port Er:fiber comb for high-stability comparison of optical lattice clocks

Ohmae

Kuse²,

Fermann³

et al. 2017

Appl. Phys. Express

View full text Add to dashboard Cite

All-polarization-maintaining, single-port Er:fiber combs offer long-term robust operation as well as high stability. We have built two such combs and evaluated the transfer noise for linking optical clocks. A uniformly broadened spectrum over 135-285 THz with a high signal-to-noise ratio enables the optical frequency measurement of the subharmonics of strontium, ytterbium, and mercury optical lattice clocks with the fractional frequencynoise power spectral density of (1-2) ' 10 %17 Hz %1/2 at 1 Hz. By applying a synchronous clock comparison, the comb enables clock ratio measurements with 10 %17 instability at 1 s, which is one order of magnitude smaller than the best instability of the frequency ratio of optical lattice clocks. © 2017 The Japan Society of Applied PhysicsO ptical frequency combs have become indispensable tools for precision measurements including atomic= molecular spectroscopy, low-phase-noise microwave generation, and ranging. 1) In optical clocks, linking different atomic clocks 2,3) or distant clocks via optical fibers 4) with a fractional uncertainty of 10 −18 is of significant concern with a future redefinition of the second in the International System of Units (SI). 5) Such endeavors, in turn, offer intriguing opportunities for testing the constancy of the fundamental constants 6) and for relativistic geodesy. 4,7) These applications necessitate ultralow-noise optical frequency combs that allow long-term and robust operation. Titanium-sapphire-based frequency combs have demonstrated outstanding stability. 8,9) However, their bulky optical setups require regular maintenance, thus hampering long-term and robust operation, which limits their potential applications. In contrast, erbium (Er) fiber combs enable all-fiber architecture for robust operation. Although a typical Er:fiber comb uses nonlinear polarization rotation (NPR) to acquire mode-locking with excellent noise performance, 9-13) the operational condition for such NPR-based Er:fiber oscillators can be sensitive to environmental conditions. For practical applications, such as the longterm operation of clocks to generate the optical second 14) and field and space applications, the all-polarization-maintaining (PM) architecture is preferred. 15,16) However, such architecture has shown relatively large phase noise. Low intrinsic phase noise with PM architecture is demonstrated by applying a nonlinear amplifying loop mirror (NALM). 17,18) In linking multiple optical frequencies, Er:fiber combs with a multibranch configuration, where each port consists of an Er-doped fiber amplifier (EDFA) and a highly nonlinear fiber (HNLF), have been employed, 3,19) as it allows sufficient output power per comb tooth optimized for the single frequency. In such a multibranch comb, the phase noise in different branches introduces the instability of ∼10 −16 at 1 s. 10,11) A record high instability of 4 × 10 −16 (τ=s) −1=2 has been demonstrated for synchronous clock comparison between strontium (Sr)-and ytterbium (Yb)-based optical lattice clocks, 3) in whic...

show abstract

Beyond the PresentSI: Optical Clocks and Quantum Radiometry

2019

The New International System of Units (SI)

View full text Add to dashboard Cite

Experimental realization of an optical second with strontium lattice clocks

Cited by 231 publications

References 50 publications

Atomic fountains and optical clocks at SYRTE: Status and perspectives

Atomic fountains and optical clocks at SYRTE: Status and perspectives

All-polarization-maintaining, single-port Er:fiber comb for high-stability comparison of optical lattice clocks

Beyond the PresentSI: Optical Clocks and Quantum Radiometry

Contact Info

Product

Resources

About