Voici les éléments 1 - 10 sur 22
  • Publication
    Accès libre
    3D printed microwave cavity for atomic clock applications: proof of concept
    (2018-6-7) ; ; ;
    Skrivervik, A.K.
    ;
    Ivanov, A.E.
    ;
    Debogovic, T.
    ;
    de Rijk, E.
    The authors present the realisation and characterisation of an additively manufactured (AM) microwave resonator cavity for double-resonance (DR) vapour-cell atomic clocks. The design of the compact microwave cavity is based on the loop-gap resonator approach, previously demonstrated for conventionally-machined aluminium components. In the present study, the resonator is fabricated by AM using a metal-coated polymer. A resonance frequency at the desired 6.835 GHz rubidium atomic frequency is obtained. When employed in an atomic clock setup, the AM cavity enables a DR signal of <;500 Hz linewidth and of nearly 20% contrast, thus fulfilling the stringent requirements for DR atomic clocks. A clock short-term stability of 1 × 10 -12 τ -1/2 is demonstrated, comparable to state-of-the-art clock performances.
  • Publication
    Métadonnées seulement
    Barometric Effect in Vapor-Cell Atomic Clocks
    Vapor-cell atomic clocks are compact and high-performance frequency references employed in various appli-cations ranging from telecommunication to global positioningsystems. Environmental sensitivities are often the main sourcesof long-term instabilities of the clock frequency. Among thesesensitivities, the environmental pressure shift describes the clockfrequency change with respect to the environmental pressurevariations. We report here on our theoretical and experimentalanalysis of the environmental pressure shift on rubidium atomicfrequency standards (RAFSs) operated under open atmosphere.By using an unsealed high-performance laser-pumped rubidiumstandard, we demonstrate that the deformation of the vapor-cell volume induced by the environmental pressure changes(i.e., barometric effect) is the dominant environmental pressureshift in a standard laboratory environment. An experimentalbarometric coefficient of 8.2×10−14/hPa is derived, in goodagreement with theory and with previously reported measure-ments of frequency shifts of RAFS operated when transiting tovacuum.
  • Publication
    Accès libre
    High performance vapour-cell frequency standards
    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.
  • Publication
    Métadonnées seulement
    High performance vapour-cell frequency standards
    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.
  • Publication
    Métadonnées seulement
    The Micro Loop-Gap Resonator: A Novel Miniaturized Microwave Cavity for Double-Resonance Rubidium Atomic Clocks
    (2014-5-22)
    Violetti, Maddalena
    ;
    ;
    Merli, Francesco
    ;
    Zürcher, Jean-François
    ;
    ; ;
    Skrivervik, A.K.
    Nowadays mobile and battery-powered applications push the need for radically miniaturized and low-power frequency standards that surpass the stability achievable with quartz oscillators. For the miniaturization of double-resonance rubidium ( 87 Rb) atomic clocks, the size reduction of the microwave cavity or resonator (MWR) to well below the wavelength of the atomic transition (6.835 GHz for 87 Rb) is of high interest. Here, we present a novel miniaturized MWR, the μ-LGR, for use in a miniature DR atomic clock and designed to apply a well-defined microwave field to a microfabricated Rb cell that provides the reference signal for the clock. This μ-LGR consists of a loop-gap resonator-based cavity with very compact dimensions (<;0.9 cm 3 ). The μ-LGR meets the requirements of the application and its fabrication and assembly can be performed using repeatable and low-cost techniques. The concept of the proposed device was proven through simulations, and prototypes were successfully tested. Experimental spectroscopic evaluation shows that the μ-LGR is well-suited for use in an atomic clock. In particular, a clock short-term stability of 7 × 10 -12 τ -1/2 was measured, which is better than for other clocks using microfabricated cells and competitive with stabilities of compact Rb clocks using conventional glass-blown cells.
  • Publication
    Accès libre
  • Publication
    Accès libre
    Low-temperature indium-bonded alkali vapor cell for chip-scale atomic clocks
    (2013-11-9)
    Straessle, Rahel
    ;
    ; ;
    Pétremand, Yves
    ;
    Briand, Danick
    ;
    ;
    De Rooij, Nicolaas-F.
  • Publication
    Accès libre
  • Publication
    Accès libre