Extremely Low Loss Phonon-Trapping Cryogenic Acoustic Cavities for Future Physical Experiments

Low loss Bulk Acoustic Wave devices are considered from the point of view of the solid state approach as phonon-confining cavities. We demonstrate effective design of such acoustic cavities with phonon-trapping techniques exhibiting extremely high quality factors for trapped longitudinally-polarized phonons of various wavelengths. Quality factors of observed modes exceed 1 billion, with a maximum $Q$-factor of 8 billion and $Q\times f$ product of $1.6\cdot10^{18}$ at liquid helium temperatures. Such high sensitivities allow analysis of intrinsic material losses in resonant phonon systems. Various mechanisms of phonon losses are discussed and estimated

About Quartz Crystal Resonator Noise: Recent Study

The first step, before investigating physical origins of noise in resonators, is to investigate correlations between external measurement parameters and the resonator noise. Tests and measurements are mainly performed on an advanced phase noise measurement system, recently set up. The resonator noise is examined as a function of the sensitivity to the drive level, the temperature operating point and the tuning capacitor.Comment: 20th International Conference on Noise and Fluctuations, Pisa : Italie (2009

Development of a 10 MHz Oscillator Working with an LGT Crystal Resonator : Preliminary results

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Losses in high quality quartz crystal resonators at cryogenic temperatures

International audienceMeasurement of the mechanical losses of quartz crystal is a topic of interest for communities dealing with the gravitational wave detectors and also the time and frequency domain. About the latter, the authors describe Q-factor measurements of quartz crystal resonators at cryogenic temperatures under 10 K, thanks to a cryocooler-based experimental set-up. A Q-factor of 325 millions at 4 K, on the fifth overtone of the quasilongitudinal mode at 15.9 MHz, has been recorded. As shown, the acoustic wave trapping is suspected to limit the Landau-Rumer regime below 6 K [Landau and Rumer, Phys. Z. Sowjetunion 11, 18 (1937)]

Quartz crystals resonators exhibiting extremaly high Q-factor at cryogenic temperatures

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Recent Investigations on BAW Resonators at Cryogenic Temperatures

International audienceThis work presents the results of investigations on different aspects of cryogenic operation of BAW resonators. For the quartz crystal resonators the losses mechanisms, the temperature sensitivity, the amplitude-frequency effect are described for liquid helium temperatures. The corresponding problems are discussed. To overcome some of these problems, the possible solution of operation at higher modes is considered. Some of these higher modes exhibit outstanding quality factors. The highest (for BAW resonators) quality factor value and quality factor-frequency product are measured for the 11th and 13th overtones respectively. In addition, two LGT resonators have been characterized in a wide temperature range. Finally, some preliminary results on utilization of cryogenic quartz resonators as a part of a frequency stabilization closed loop system are given

Inter-laboratory time and frequency transfer by optical fibers.

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Dark Line Resonances in Cs-Ne Vapor Microcells for Chip Scale Atomic Clocks

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The effect of power-drive level on the calibration of the bridge instrument for the measurement of the quartz stability

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