3D speckle cooling in a microwave clock Pottie, P.-E.; Tremine, S.; Guerandel, S. ...
IEEE International Frequency Control Symposium and PDA Exhibition Jointly with the 17th European Frequency and Time Forum, 2003. Proceedings of the 2003,
2003
Conference Proceeding
Sub-Doppler laser cooling is studied in an optically polished microwave cavity used as a reflecting cell. Light potential wells due to the speckle field in the cell make Sisyphus cooling mechanisms ...possible. For a 1 s capture time, about 10/sup 8/ cesium atoms are cooled at temperatures in the microkelvin range from thermal vapor. These results are discussed and compared with the basic theoretical model involving two laser beams lin /spl perp/ lin polarized. For a microwave clock using such cold atoms, the pulsed operation is precised and the main frequency shifts are evaluated. The short term relative frequency stability is expected to be lower than 10/sup -12//spl tau//sup - 1/2 /.
The ACES project aims at operating ultra stable clocks on board the International Space Station ISS and comparing them to ground clocks located all around the world. The expected performance of ACES ...space clocks (frequency stability and accuracy at 10 -16 level) and of the dedicated microwave link (time stability better than 10 ps over 1 day) will be of great interest for time & frequency metrology (comparison of ground primary standards with a resolution better than 10 -16) and for fundamental physics (relativity tests).
Toward compact clocks with cold cesium atoms Guillemot, C.; Guillot, E.; Petit, P. ...
1998 Conference on Precision Electromagnetic Measurements Digest (Cat. No.98CH36254),
1998
Conference Proceeding
We present first a new 3-dimensional cooling configuration with isotropic light. We demonstrate that this cooling technique is very efficient and easy to operate. Secondly, we present two simple ...clock configurations using a source of atoms cooled in isotropic light. We expect these clocks to be very compact with good frequency performances.
Two projects of compact cold atom clocks are currently developed: a clock with atoms directly cooled in the microwave cavity and a clock based on coherent population trapping. For each device, ...different interrogation and detection schemes are evaluated and reported
Atomic Clock Ensemble in Space (ACES) is a mission in fundamental physics that will operate a new generation of atomic clocks in the microgravity environment of the International Space Station. ...Fractional frequency instability and inaccuracy at the 10
−16 level will be achieved. The on-board time base, distributed on Earth via a microwave link, will be used for space-to-ground as well as ground-to-ground comparisons of atomic frequency standards. Based on these comparisons, ACES will perform fundamental physics tests and develop applications in time and frequency metrology, universal time scales, global positioning and navigation, geodesy, and gravimetry. After a general overview of the mission concept and its scientific objectives, the present status of ACES instruments and sub-systems will be discussed.
We have studied the properties of a noisy laser diode light tuned near the D2 line of cesium resonance transition after passing through an atomic-cesium vapour cell. We have found that the ...transmitted beam acquires excess noise. This noise depends on the laser linewidth, laser detuning, intensity, and Fourier frequency.
In space, thanks to micro-gravity conditions, a clock using laser cooled atoms is expected to have a better performance than on Earth. We have constructed a prototype of this space clock. It was ...tested in the absence of gravity of aircraft parabolic flights, yielding an atomic resonance with a width of 7 Hz, twice narrower than on Earth.
Dick effect and cavity pulling on HORACE compact cold atom clock Rossetto, N.; Esnault, F. X.; Holleville, D. ...
2011 Joint Conference of the IEEE International Frequency Control and the European Frequency and Time Forum (FCS) Proceedings
Conference Proceeding
HORACE is a compact cold caesium (Cs) atom clock using isotropic light cooling technique directly inside the spherical microwave cavity. It has been designed for onboard and space applications. ...Ultimate stability as low as 2.2 10 -13 τ -1/2 had been demonstrated, limited by atomic shot noise and quantum projection noise. Influence of Dick effect has been studied and a compact and simple frequency synthesizer using off the shelf quartz has been realized and characterized. As atoms remain in the cavity during Ramsey sequence, long term stability evaluation focused on cavity pulling effect. This proceeding presents both the microwave synthesizer development and cavity pulling study using a tricky technique to tune the microwave cavity.
A cold atom clock in absence of gravity Laurent, P.; Lemonde, P.; Simon, E. ...
The European physical journal. D, Atomic, molecular, and optical physics,
1998, Letnik:
3, Številka:
3
Journal Article
