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Université de Neuchâtel

Long-Term Stability Analysis Towards <10-14 Level for a Highly Compact POP Rb Cell Atomic Clock

Almat, Nil ; Gharavipour, Mohammadreza ; Moreno, William ; Gruet, Florian ; Affolderbach, Christoph ; Mileti, Gaetano

In: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2020, vol. 67, no. 1, p. 207-216

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...

Université de Neuchâtel

Rubidium vapour-cell frequency standards : metrology of optical and microwave frequency references

Moreno, William ; Mileti, Gaetano (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2019.

This thesis concerns the development, study, and optimisation of compact and high-performance frequency references based on rubidium (Rb) vapour cells1. More specially, two Rb vapour-cell frequency references are studied: an optical-frequency reference at 1.5 μm and a double-resonance pulsed optically pumped (POP) atomic clock. The use of vapour cells allows compact frequency...

Université de Neuchâtel

Ramsey spectroscopy in a Rubidium vapor cell and realization of an ultra-stable atomic clock

Gharavipour, Mohammadreza ; Mileti, Gaetano (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2018.

Various application fields in industry, telecommunication, navigation and space demand reliable, compact, high-performance frequency standards with a stability level of −14 at 105s (equivalent to <1ns/day). Thanks to semiconductor technology, optical pumping technique with a laser has opened up new schemes based on laser-microwave double-resonance (DR), such as...

Université de Neuchâtel

First uncertainty evaluation of the FoCS-2 primary frequency standard

Jallageas, Antoine ; Devenoges, Laurent ; Petersen, M ; Morel, J ; Bernier, L. G ; Schenker, Dominique ; Thomann, Pierre ; Südmeyer, Thomas

In: Metrologia, 2018, vol. 55, no. 3, p. 366-385

We report the uncertainty evaluation of the Swiss continuous primary frequency standard FoCS-2 (Fontaine Continue Suisse). Unlike other primary frequency standards which are working with clouds of cold atoms, this fountain uses a continuous beam of cold caesium atoms bringing a series of metrological advantages and specific techniques for the evaluation of the uncertainty budget. Recent...

Université de Neuchâtel

Characterization of Frequency-Doubled 1.5-μm Lasers for High-Performance Rb Clocks

Almat, Nil ; Moreno, William ; Pellaton, Matthieu ; Gruet, Florian ; Affolderbach, Christoph ; Mileti, Gaetano

In: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2018, vol. 65, no. 6, p. 919-926

We report on the characterization of two fiber-coupled 1.5- μm diode lasers, frequency-doubled and stabilized to Rubidium (Rb) atomic resonances at 780 nm. Such laser systems are of interest in view of their implementation in Rb vaporcell atomic clocks, as an alternative to lasers emitting directly at 780 nm. The spectral properties and the instabilities of the frequency-doubled lasers are...

Université de Neuchâtel

Fabrication and characterization of MEMS alkali vapor cells used in chip-scale atomic clocks and other atomic devices

Karlen, Sylvain ; Mileti, Gaetano (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2018.

Atomic clocks are timekeeping devices that can achieve extreme performance in terms of stability and accuracy. Behind this name, hides a variety of different systems which size and complexity can be considerably different depending on their applications. The primary frequency standards used for the realization of the second and the clocks mounted on the Galileo satellite positioning system are...

Université de Neuchâtel

Design of atomic clock cavity based on a loop-gap geometry and modified boundary conditions

Ivanov, Anton E ; Affolderbach, Christoph ; Mileti, Gaetano ; Skrivervik, Anja K

In: International Journal of Microwave and Wireless Technologies, 2017, vol. 9, no. 7, p. 1373-1386

In this study, we investigate a concept that can be used to improve the magnetic field homogeneity in a microwave cavity applied in a novel, high-performance atomic frequency standard. We show that by modifying the boundary conditions in the case of a loop-gap geometry, a good improvement of the field homogeneity can be obtained. Such a design demonstrates high potential to improve the frequency...

Université de Neuchâtel

Évaluation métrologique de l'étalon primaire de fréquence FoCS-2 avec une incertitude de quelques 10-15

Jallageas, Antoine ; Südmeyer, Thomas (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2017.

This work focusses on the study and the metrological evaluation of the FoCS-2 primary frequency standard. This atomic clock, one of a kind, uses a continuous beam of cold cesium atoms. Following 20 years of development in the Observatory of Neuchâtel and the Time and Frequency Laboratory of the University of Neuchâtel, FoCS-2 is now located in the federal institute of metrology METAS in Bern....

Université de Neuchâtel

Status and prospect of the Swiss continuous Cs fountain FoCS-2

Jallageas, Antoine ; Devenoges, Laurent ; Petersen, Michael ; Morel, Jacques ; Bernier, Laurent-Guy ; Thomann, Pierre ; Südmeyer, Thomas

In: Journal of Physics: Conference Series, 2016, vol. 723, no. 1, p. 012010

The continuous cesium fountain clock FoCS-2 at METAS presents many unique characteristics and challenges in comparison with standard pulsed fountain clocks. For several years FoCS-2 was limited by an unexplained frequency sensitivity on the velocity of the atoms, in the range of 140 · 10-15. Recent experiments allowed us to identify the origin of this problem as undesirable microwave...