Phase variations in microwave cavities for atomic clocks

Li, Ruoxin; Gibble, Kurt

doi:10.1088/0026-1394/41/6/004

Cited by 63 publications

(139 citation statements)

References 16 publications

Supporting

Mentioning

137

Contrasting

Order By: Relevance

“…We evaluate this shift by applying the approach established in [52] for FO2-Cs, which is based on a theoretical model of the cavity field developed in [53] [54]. In this approach, the leading contributions from the lowest azimuthal terms m = 0, m = 1 and m = 2 of the phase distribution in the cavity are considered.…”

Section: Distributed Cavity Phase Shiftmentioning

confidence: 99%

Contributing to TAI with a secondary representation of the SI second

et al. 2014

View full text Add to dashboard Cite

Abstract-We report the first contribution to the international atomic time (TAI) based on a secondary representation of the SI second. This work is done with the LNE-SYRTE FO2-Rb fountain frequency standard using the 87 Rb ground state hyperfine transition. We describe FO2-Rb and how it is connected to local and international time scales. We report on local measurements of this frequency standard in the SI system, i.e. against primary frequency standards, down to a fractional uncertainty of 4.4 × 10 −16 , and on the establishment of the recommended value for the 87 Rb hyperfine transition by the CIPM. We also report on the process that led to the participation of the FO2-Rb frequency standard to Circular T and to the elaboration of TAI. This participation enables us to demonstrate absolute frequency measurement directly in terms of the SI second realized by the TAI ensemble with a statistical uncertainty of 1.1 × 10 −16 , therefore at the limit allowed by the accuracy of primary frequency standards. This work constitutes a demonstration of how other secondary representations, based on optical transitions, could also be used for TAI, and an investigation of a number of issues relevant to a future redefinition of the SI second.

show abstract

Section: Distributed Cavity Phase Shiftmentioning

confidence: 99%

Contributing to TAI with a secondary representation of the SI second

et al. 2014

View full text Add to dashboard Cite

show abstract

“…They use a large number of atoms confined in the Lamb-Dicke regime by an optical lattice in which the first order perturbation of the clock transition cancels [9]. Due to the lattice confinement motional effects, which set a severe limitation to standards with neutral atoms in free fall [10,11], essentially vanish [12]. This gives hope for a ultimate fractional accuracy better than 10 −17 .…”

mentioning

confidence: 99%

Accurate Optical Lattice Clock withSr87Atoms

et al. 2006

View full text Add to dashboard Cite

We report a frequency measurement of the 1 S0 − 3 P0 transition of 87 Sr atoms in an optical lattice clock. The frequency is determined to be 429 228 004 229 879 (5) Hz with a fractional uncertainty that is comparable to state-of-the-art optical clocks with neutral atoms in free fall. Two previous measurements of this transition were found to disagree by about 2 × 10 −13 , i.e. almost four times the combined error bar, instilling doubt on the potential of optical lattice clocks to perform at a high accuracy level. In perfect agreement with one of these two values, our measurement essentially dissipates this doubt.PACS numbers: 06.30. Ft,42.50.Hz,42.62.Fi Recent advances in the field of optical frequency metrology make measurements with a fractional accuracy of 10 −17 or better a realistic short term goal [1]. Among other possible applications (e.g. a redefinition of the S.I. second, optical very long baseline interferometry in space, direct mapping of the earth gravitational using the Einstein effect,...), a very interesting prospect with measurements at that level is a reproducible test of Einstein Equivalence Principle by the repeated determination of the frequency ratio of different atomic and molecular transitions [2,3,4,5,6,7]. The topicality of such a test has recently been renewed by measurements at the cosmological scale which seem to indicate a slow variation of the electron to proton mass ratio [8]. The richness of the test directly depends on the performance of the clocks that are used but also on the variety of clock transitions and atomic species on which high accuracy frequency standards are based.In that context, optical lattice clocks are expected to play a central role in the future of this field. They use a large number of atoms confined in the Lamb-Dicke regime by an optical lattice in which the first order perturbation of the clock transition cancels [9]. Due to the lattice confinement motional effects, which set a severe limitation to standards with neutral atoms in free fall [10,11], essentially vanish [12]. This gives hope for a ultimate fractional accuracy better than 10 −17 . On the other hand, the large number of atoms in an optical lattice clock in principle opens the way to a short term fractional frequency stability significantly better than 10 −15 τ −1/2 with τ the averaging time in seconds. In this regime the coherence time of the laser frequency locked to the clock transition would be several seconds, possibly tens of seconds [25]. Such a long coherence time could for instance be used to reduce the width of the optical resonances in single ion clocks down to or below the 0.1 Hz range opening new prospects for these devices also. Finally, the optical lattice clock scheme is in principle applicable to a large number of atomic species (Sr, Yb, Hg, Ca, Mg,...) which is a key feature for the fundamental test discussed above. It is then particularly problematic that the frequency delivered by the first two evaluated optical lattice clocks, which both use 87 Sr, disagree by about 2 × ...

show abstract

“…The Penn State group has obtained similar but more complete power series expansions [20]. The expansion of the field in terms of a normal mode picture (Eq.…”

Section: Microwave Cavities and Phasementioning

confidence: 90%

“…The coefficients A n,m,l and B n,m,l for l=2,4,…2n should be quite small for a cavity with midplane feeds; however, this may not be true for the "improved" cavity design described in [20]. Additionally with mid-plane fed cavities the predominant power flow caused by coupling imbalance is orthogonal to the atomic trajectory, resulting in a high degree of rejection of the first order Doppler shift; this feature is lost in cavities not using the midplane feed such as those in [20], which exhibit a high sensitivity to first order Doppler shifts.…”

Section: Microwave Cavities and Phasementioning

confidence: 99%

“…DeMarchi provided the seminal contributions of proving a correspondence between the phase and power-flows within the microwave cavity, identifying the preferred cavity configuration and modeling the phase of the microwave field within the cavity [12][13][14][15]. Three-dimensional analyses of the microwave field within the cavity have been completed by several authors [16][17][18][19][20]. In many of these studies large phase excursions are predicted.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation