Voici les éléments 1 - 10 sur 88
- PublicationMétadonnées seulementHigh performance vapour-cell frequency standards(: Journal of Physics: Conference Series 723, 2015-10-27)
; ; ; ; ; ;We report our investigations on a compact high-performance rubidium (Rb) vapour-cell clock based on microwave-optical double-resonance (DR). These studies are done in both DR continuous-wave (CW) and Ramsey schemes using the same Physics Package (PP), with the same Rb vapour cell and a magnetron-type cavity with only 45 cm3 external volume. In the CW-DR scheme, we demonstrate a DR signal with a contrast of 26% and a linewidth of 334 Hz; in Ramsey-DR mode Ramsey signals with higher contrast up to 35% and a linewidth of 160 Hz have been demonstrated. Short-term stabilities of 1.4×10^-13 τ^-1/2 and 2.4×10^-13 τ^-1/2 are measured for CW-DR and Ramsey-DR schemes, respectively. In the Ramsey-DR operation, thanks to the separation of light and microwave interactions in time, the light-shift effect has been suppressed which allows improving the long-term clock stability as compared to CW-DR operation. Implementations in miniature atomic clocks are considered.
- PublicationAccès libreMicrofabricated chip-scale rubidium plasma light source for miniature atomic clocks(2012-11-9)
;Venkatraman, Vinu ;Pétremand, Yves ; ; ;De Rooij, Nicolaas-F.Shea, Herbert
- PublicationAccès libreHigh-performance laser pumped rubidium frequency standard for satellite navigation(2011)
;Bandi, T. ; ;Calosso, C.E.Presented is a double-resonance continuous-wave laser-pumped rubidium (Rb) atomic clock with a short-term stability of 4 × 10(-13) t(-1/2) for integration times 1 s ≤ t ≤ 1000 s, and a medium- to longterm stability reaching the 1 × 10(-14) level at 10(4) s. The clock uses an Rb vapour cell with increased diameter of 25 mm, accommodated inside a newly developed compact magnetron-type microwave cavity. This results in a bigger signal with reduced linewidth, and thus improved short-term stability from a clock with 1 dm(3) physics package volume only. The medium- to long-term clock stability is achieved by minimising the effects of light-shift and temperature coefficient on the atoms. Potential applications of the clock are discussed.
- PublicationMétadonnées seulementLong-Term Stability Analysis Towards < 10-14 Level for a Highly Compact POP Rb Cell Atomic Clock(2019-4-14)
; ; ; ;Long-term frequency instabilities in vapor-cell clocks mainly arise from fluctuations of the experimental and environmental parameters that are converted to clock frequency fluctuations via various physical processes. Here, we discuss the frequency sensitivities and the resulting stability limitations at one day timescale for a rubidium vapor-cell clock based on a compact magnetron-type cavity operated in air (no vacuum environment). Under ambient laboratory conditions, the external atmospheric pressure fluctuations may dominantly limit the clock stability via the barometric effect. We establish a complete long-term instability budget for our clock operated under stable pressure conditions. Where possible, the fluctuations of experimental parameters are measured via the atomic response. The measured clock instability of < 2·E10.14 at one day is limited by the intensity light-shift effect, which could further be reduced by active stabilization of the laser intensity or stronger optical pumping. The analyses reported here show the way towards simple, compact, and low-power vapor-cell atomic clocks with excellent long-term stabilities. ≤ 10.14 at one day when operated in ambient laboratory conditions.
- PublicationMétadonnées seulementTuneable, stabilised diode lasers for compact atomic frequency standards and precision wavelength references(2005)
;We describe the ongoing activities in Observatoire Cantonal de Neuchatel in the fields of precision laser spectroscopy and metrology of Rb atomic vapours. The work is motivated by the potentials of highly stable and narrowband laser light Sources for a variety of technical and scientific applications. We describe the use of extended-cavity diode lasers for the realisation of such narrowband light sources and the basic schemes under Study for their stabilisation, with focus on Doppler and sub-Doppler laser spectroscopy. The resulting laser systems offer good frequency stabilities and can be effectively miniaturised. This makes them interesting for direct applications of these techniques, as well as the presently developed precision instruments: compact atomic frequency standards for ground and space applications (GALILEO satellite positioning system), secondary optical frequency standards, transportable extended cavity diode lasers as seeding lasers, and others. (c) 2004 Elsevier Ltd. All rights reserved.
- PublicationAccès libreImaging of relaxation times and microwave field strength in a microfabricated vapor cell(2013-11-9)
;Horsley, Andrew ;Du, Guan-Xiang ; ; ;Treutlein, Philipp
- PublicationAccès libreStudy of laser-pumped double-resonance clock signals using a microfabricated cell(2012-11-9)
; ; ;Pétremand, Yves ;De Rooij, Nicolaas-F.
- PublicationAccès libreCompact microwave cavity for high performance rubidium frequency standards(2012-11-9)
; ;Bandi, Thejesh ;Merli, Francesco ; ; ;Skrivervik, Anja K.
- PublicationMétadonnées seulementDouble-resonance spectroscopy in Rubidium vapour-cells for high performance and miniature atomic clocks(2017-2-16)
; ; ;Kang, SWe report our studies on using microwave-optical double-resonance (DR) spectroscopy for a high-performance Rb vapour-cell atomic clock in view of future industrial applications. The clock physics package is very compact with a total volume of only 0.8 dm3. It contains a recently in-house developed magnetron-type cavity and a Rb vapour cell. A homed-made frequency-stabilized laser system with an integrated acousto-optical-modulator (AOM) – for switching and controlling the light output power– is used as an optical source in a laser head (LH). The LH has the overall volume of 2.5 dm3 including the laser diode, optical elements, AOM and electronics. In our Rb atomic clock two schemes of continuous-wave DR and Ramsey-DR schemes are used, where the latter one strongly reduces the light-shift effect by separation of the interaction of light and microwave. Applications of the DR clock approach to more radically miniaturized atomic clocks are discussed.
- PublicationAccès libreHigh performance vapour-cell frequency standardsWe report our investigations on a compact high-performance rubidium (Rb) vapour-cell clock based on microwave-optical double-resonance (DR). These studies are done in both DR continuous-wave (CW) and Ramsey schemes using the same Physics Package (PP), with the same Rb vapour cell and a magnetron-type cavity with only 45 cm3 external volume. In the CW-DR scheme, we demonstrate a DR signal with a contrast of 26% and a linewidth of 334 Hz; in Ramsey-DR mode Ramsey signals with higher contrast up to 35% and a linewidth of 160 Hz have been demonstrated. Short-term stabilities of 1.4×10-13 τ-1/2 and 2.4×10-13 τ-1/2 are measured for CW-DR and Ramsey-DR schemes, respectively. In the Ramsey-DR operation, thanks to the separation of light and microwave interactions in time, the light-shift effect has been suppressed which allows improving the long-term clock stability as compared to CW-DR operation. Implementations in miniature atomic clocks are considered.