Advanced Satellite-Based Frequency Transfer at the 10<sup>−16</sup> Level

Fujieda, Miho; Yang, Seung-Ho; Gotoh, Tadahiro; Hwang, Sang-Wook; Hachisu, Hidekazu; Kim, Huidong; Lee, Young Kyu; Tabuchi, Ryo; Ido, T.; Lee, Won-Kyu; Heo, Myoung-Sun; Park, Chang Yong; Yu, Dai-Hyuk; Petit, Gérard

doi:10.1109/tuffc.2018.2821159

Cited by 48 publications

(31 citation statements)

References 13 publications

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“…A frequency ratio can also be determined directly from optical frequency ratio measurements. From a weighted average of six optical ratio measurements [49][50][51][52][53][54], we determine R avg opt = 1.207 507 039 343 337 768 (60). We therefore determine a loop misclosure of (R abs − R opt )/R = (0.8 ± Were this violation to occur, it might arise due to variation of the fine structure constant, α; the ratio of the light quark mass to the quantum chromodynamics (QCD) scale, X q = m q /Λ QCD ; or the electron-to-proton mass ratio, µ = m e /m p .…”

Section: Results and Analysismentioning

confidence: 99%

“…Then, this value is added to y avg (AT1−TAI), the average frequency difference between the NIST This good agreement using a very different analysis method demonstrates that the results in the main text are robust against alternative methods of analysis. To tighten the contraints on the possible variations of fundamental constants, we employ a multi-species analysis that can be used to link absolute frequency measurements of [49][50][51][52][53][54] as described in the main text. The ratio is known with a fractional uncertainty of σ stat = 5.6 × 10 −17 .…”

Section: Appendix B: Frequency Connection To Psfsmentioning

confidence: 99%

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Towards the optical second: verifying optical clocks at the SI limit

McGrew

Zhang

Leopardi

et al. 2019

Optica

119

110

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The pursuit of ever more precise measures of time and frequency is likely to lead to the eventual redefinition of the second in terms of an optical atomic transition. To ensure continuity with the current definition, based on a microwave transition between hyperfine levels in ground-state 133 Cs, it is necessary to measure the absolute frequency of candidate standards, which is done by comparing against a primary cesium reference. A key verification of this process can be achieved by performing a loop closure-comparing frequency ratios derived from absolute frequency measurements against ratios determined from direct optical comparisons. We measure the 1 S 0 → 3 P 0 transition of 171 Yb by comparing the clock frequency to an international frequency standard with the aid of a maser ensemble serving as a flywheel oscillator. Our measurements consist of 79 separate runs spanning eight months, and we determine the absolute frequency to be 518 295 836 590 863.71(11) Hz, the uncertainty of which is equivalent to a fractional frequency of 2.1 × 10 −16 .This absolute frequency measurement, the most accurate reported for any transition, allows us to close the Cs-Yb-Sr-Cs frequency measurement loop at an uncertainty of <3×10 −16 , limited by the current realization of the SI second. We use these measurements to tighten the constraints on variation of the electron-to-proton mass ratio, µ = m e /m p . Incorporating our measurements with the entire record of Yb and Sr absolute frequency measurements, we infer a coupling coefficient to gravitational potential of k µ = (−1.9 ± 9.4) × 10 −7 and a drift with respect to time oḟ µ µ = (5.3 ± 6.5) × 10 −17 /yr. arXiv:1811.05885v1 [physics.atom-ph]

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Section: Results and Analysismentioning

confidence: 99%

Section: Appendix B: Frequency Connection To Psfsmentioning

confidence: 99%

Towards the optical second: verifying optical clocks at the SI limit

McGrew

Zhang

Leopardi

et al. 2019

Optica

119

110

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“…The demonstrated long-term stability floor is comparable to that obtained in the most sophisticated satellite frequency transfer techniques [38], [39], the fiber-optic approach, however, allows obtaining results a hundred times faster. On the other hand, it may be concluded that the cost-effectiveness of using standard DWDM infrastructure is sacrificed by significant stability degradation when compared with a bidirectional transfer in a single fiber.…”

Section: Discussionmentioning

confidence: 68%

Stability Limitations of Optical Frequency Transfer in Telecommunication DWDM Networks

Turza

Krehlik

Śliwczyński

2020

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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This article investigates the fundamental limitations of optical frequency transfer stability related to cost-effective implementation of signal transmission in duplex, unidirectional optical paths offered by a standard dense wavelength division multiplexing (DWDM) network. We pointed out the effect of a significant mismatch of phase fluctuations observed in pairs of fibers even when located in a common cable. We also measured the thermal sensitivities of individual DWDM optical modules in the context of the effectiveness of the signal stabilization system. Finally, we present the real implementation of the coherent optical carrier transfer in the operational DWDM network, showing the overall impact of all individual effects. We demonstrated that it is possible to obtain the long-term stability (one day averaging) within the range from 2 × 10 −16 to 4 × 10 −16 and typical frequency offset at the level of few times 10 −16 in a 1500-km-long line by using the soil-deployed cables.Index Terms-Alien wavelength, dense wavelength division multiplexing (DWDM) network, optical fiber, optical frequency transfer.

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“…2) HXI Receiver: At the HXI receiver shown in Fig. 3(b), the received signal r (t) is 4 1 e j (2π(4 f c1 )t+4φ…”

Section: B Impact Of Free-running Dielectric Resonator Oscillatorsmentioning

confidence: 99%

White Rabbit Time and Frequency Transfer Over Wireless Millimeter-Wave Carriers

Gilligan

Konitzer

Siman-Tov

et al. 2020

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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We demonstrate time and frequency transfer using a White Rabbit (WR) time transfer system over millimeter-wave (mm-wave) 71-76 GHz carriers. To validate the performance of our system, we present overlapping Allan deviation (ADEV), time deviation (TDEV), and phase statistics. Over mm-wave carriers, we report an ADEV of 7.1 × 10 −12 at 1 s and a TDEV of <10 ps at 10 000 s. Our results show that after 4 s of averaging, we have sufficient precision to transfer a cesium atomic frequency standard. We analyze the link budget and architecture of our mm-wave link and discuss possible sources of phase error and their potential impact on the WR frequency transfer. Our data show that WR can synchronize new network architectures, such as physically separated fiber-optic networks, and support new applications, such as the synchronization of intermittently connected platforms. We conclude with recommendations for future investigation, including cascaded hybrid wireline and wireless architectures. Index Terms-Millimeter wave (mm-wave), time transfer, White Rabbit (WR), wireless.

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Advanced Satellite-Based Frequency Transfer at the 10⁻¹⁶ Level

Cited by 48 publications

References 13 publications

Towards the optical second: verifying optical clocks at the SI limit

Towards the optical second: verifying optical clocks at the SI limit

Stability Limitations of Optical Frequency Transfer in Telecommunication DWDM Networks

White Rabbit Time and Frequency Transfer Over Wireless Millimeter-Wave Carriers

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Advanced Satellite-Based Frequency Transfer at the 10−16 Level

Cited by 48 publications

References 13 publications

Towards the optical second: verifying optical clocks at the SI limit

Towards the optical second: verifying optical clocks at the SI limit

Stability Limitations of Optical Frequency Transfer in Telecommunication DWDM Networks

White Rabbit Time and Frequency Transfer Over Wireless Millimeter-Wave Carriers

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Product

Resources

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Advanced Satellite-Based Frequency Transfer at the 10⁻¹⁶ Level