Uncertainty evaluation of the atomic caesium fountain CSF1 of the PTB

Weyers, S.; Bner, U. H; der, R. Schr; Tamm, Chr.; Bauch, A.

doi:10.1088/0026-1394/38/4/7

Cited by 157 publications

(136 citation statements)

References 16 publications

Supporting

Mentioning

135

Contrasting

Unclassified

Order By: Relevance

“…In this way the frequency of the octupole transition was measured with a fiber-laserbased frequency comb generator [20] using the caesium fountain clock CSF1 [21] in our laboratory as the reference. Table I shows the results of eight measurements with different settings of I H and I L .…”

mentioning

confidence: 99%

High-Accuracy Optical Clock Based on the Octupole Transition inYb+171

Huntemann

Okhapkin²,

Lipphardt³

et al. 2012

Phys. Rev. Lett.

236

215

View full text Add to dashboard Cite

We experimentally investigate an optical frequency standard based on the 467 nm (642 THz) electric-octupole reference transition 2 S 1/2 (F = 0) → 2 F 7/2 (F = 3) in a single trapped 171 Yb + ion. The extraordinary features of this transition result from the long natural lifetime and from the 4f 13 6s 2 configuration of the upper state. The electric-quadrupole moment of the 2 F 7/2 state is measured as −0.041(5) ea 2 0 , where e is the elementary charge and a0 the Bohr radius. We also obtain information on the differential scalar and tensorial components of the static polarizability and of the probe-light-induced ac Stark shift of the octupole transition. With a real-time extrapolation scheme that eliminates this shift, the unperturbed transition frequency is realized with a fractional uncertainty of 7.1 × 10 −17 . The frequency is measured as 642 121 496 772 The basis of all precise atomic clocks is a transition frequency that represents an unperturbed quantum property of the chosen atomic system. The most impressive progress in clocks of high accuracy has recently been made with optical transitions between states with vanishing electronic angular momentum (J = 0) in Al + and Sr [1,2]. The frequency of this type of transition is in general only weakly affected by external electric and magnetic fields. Here we present a precision study of a reference transition of a very different type, an electric-octupole transition (∆J = 3) connecting the 2 S 1/2 ground state with the 2 F 7/2 first excited state in 171 Yb + , and show that it has a very low sensitivity to field-induced frequency shifts, making it a promising basis for an optical clock of the highest accuracy.At variance with other ion frequency standards, 171 Yb + offers the advantage of two optical reference transitions with high quality factor which have rather different physical characteristics. A frequency standard based on the electric-quadrupole 2 S 1/2 → 2 D 3/2 transition [3,4] is established as one of the secondary representations of the SI second. The electric-octupole 2 S 1/2 → 2 F 7/2 transition investigated in this Letter was first studied at the National Physical Laboratory (UK) [5]. The extraordinary features of this transition result from the long natural lifetime of the 2 F 7/2 state in the range of several years [5,6] and from its electronic configuration (4f 13 6s 2 ) consisting of a hole in the 4f shell surrounded by a spherically symmetric 6s shell. Since the octupole transition can be resolved with a linewidth that is virtually unaffected by spontaneous decay and determined only by the available laser stability, a quantum projection noise limited single-ion frequency standard with very low instability can be realized. The electric-quadrupole moment of the 2 F 7/2 state is predicted to be much smaller than that of the 2 D 3/2 state [7] so that the transition frequency is only weakly affected by the quadrupole shift from electric field gradients. Furthermore, there are no strong dipole transitions from the 2 F 7/2 state with excitation en...

show abstract

mentioning

confidence: 99%

High-Accuracy Optical Clock Based on the Octupole Transition inYb+171

Huntemann

Okhapkin²,

Lipphardt³

et al. 2012

Phys. Rev. Lett.

236

215

View full text Add to dashboard Cite

show abstract

“…The recent advances in optical frequency synthesis and metrology by using femtosecond mode-locked lasers [1][2][3][4] as well as progress in microwave frequency standards with cooled atoms [5][6][7] and cryogenic oscillators [8], opened a promising era in time-frequency standards. The enormous simplification of absolute frequency measurements in the optical range and the possibility of one-step coherent transfer of optical reference stability to the microwave range put optical frequency standards into a new perspective.…”

Section: Introductionmentioning

confidence: 99%

Absolute frequency measurement of the iodine-stabilized Ar+ laser at 514.6 nm using a femtosecond optical frequency comb

et al. 2004

View full text Add to dashboard Cite

show abstract

“…Cesium fountains have been contributing to International Atomic Time (TAI) as the most accurate primary frequency standards for more than a decade [11,12] , and rubidium fountains have been accepted as a secondary standard [1,3] . To date, atomic fountain clocks (AFCs) have achieved a low 1 × 10 −16 level of total uncertainties and long-term stability of a low 1 × 10 −16 even to the 1 × 10 −17 level [1][2][3][4] .…”

mentioning

confidence: 99%

Untitled

2017

中国光学快报

View full text Add to dashboard Cite

The environmental perturbation on atoms is a key factor restricting the performance of atomic frequency standards, especially in the long-term scale. In this Letter, we perform a real-time noise distinguish (RTND) to an atomic clock to decrease the uncertainty of the atomic clock beyond the level that is attained by the current controlling method. In RTND, the related parameters of the clock are monitored in real time by using the calibrated sensors, and their effects on the clock frequency are calculated. By subtracting the effects from the error signal, the local oscillator is treated as equivalently locked to the unperturbed atomic levels. In order to perform quantitative tests, we engineer time-varying noise much larger than the intrinsic noise in our fountain atomic clock. By using RTND, the influences of the added noises are detected and subtracted precisely from the error signals before feeding back to the reference oscillator. The result shows that the statistical uncertainty of our fountain clock is improved by an order of magnitude to 2 × 10 −15 . Besides, the frequency offset introduced by the noise is also corrected, while the systematic uncertainty is unaffected.

show abstract

Uncertainty evaluation of the atomic caesium fountain CSF1 of the PTB

Cited by 157 publications

References 16 publications

High-Accuracy Optical Clock Based on the Octupole Transition inYb+171

High-Accuracy Optical Clock Based on the Octupole Transition inYb+171

Absolute frequency measurement of the iodine-stabilized Ar+ laser at 514.6 nm using a femtosecond optical frequency comb

Untitled

Contact Info

Product

Resources

About