Affiner les résultats

Type de document

Collection spécifique


Accès public à partir du 1 mars 2020
Université de Neuchâtel

Impact of microwave-field inhomogeneity in an alkali vapour cell using Ramsey double-resonance spectroscopy

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

In: Quantum Electronics, 2019, vol. 49, no. 3, p. 293-297

We numerically and experimentally evaluate the impact of the inhomogeneity of the microwave field in the cavity used to perform double-resonance (DR) Ramsey spectroscopy in a buffer gas alkali vapour cell. The Ramsey spectrum is numerically simulated using a simple theoretical model and taking into account the field distribution in a magnetron-type microwave resonator. An experimental evaluation...

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

Rb vapor-cell clock demonstration with a frequency-doubled telecom laser

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

In: Applied Optics, 2018, vol. 57, no. 16, p. 4707-4713

We employ a recently developed laser system, based on a low-noise telecom laser emitting around 1.56 μm, to evaluate its impact on the performance of an Rb vapor-cell clock in a continuous-wave double-resonance scheme. The achieved short-term clock instability below 2.5·10−13·τ−1∕2 demonstrates, for the first time, the suitability of a frequency-doubled...

Université de Neuchâtel

Optically-detected spin-echo method for relaxation times measurements in a Rb atomic vapor

Gharavipour, Mohammadreza ; Affolderbach, Christoph ; Gruet, Florian ; Radojičić, I. S ; Krmpot, A. J ; Jelenković, B. M ; Mileti, Gaetano

In: New Journal of Physics, 2017, vol. 19, no. 063027, p. 1-11

We introduce and demonstrate an experimental method, optically-detected spin-echo (ODSE), to measure ground-state relaxation times of a rubidium (Rb) atomic vapor held in a glass cell with buffer-gas. The work is motivated by our studies on high-performance Rb atomic clocks, where both population and coherence relaxation times ( T1 and T2 , respectively ) of the ‘ clock transition...

Université de Neuchâtel

Interferometric measurements beyond the coherence length of the laser source

Salvadé, Yves ; Przygodda, Frank ; Rohner, Marcel ; Polster, Albert ; Meyer, Yves ; Monnerat, Serge ; Gloriod, Olivier ; Llera, Miguel ; Matthey, Renaud ; Di Francesco, Joab ; Gruet, Florian ; Mileti, Gaetano

In: Optics Express, 2016, vol. 24, no. 19, p. 21729-21743

Interferometric measurements beyond the coherence length of the laser are investigated theoretically and experimentally in this paper. Thanks to a high-bandwidth detection, high-speed digitizers and a fast digital signal processing, we have demonstrated that the limit of the coherence length can be overcome. Theoretically, the maximal measurable displacement is infinite provided that the sampling...

Université de Neuchâtel

Rb-stabilized laser at 1572 nm for CO2 monitoring

Matthey, Renaud ; Moreno, William ; Gruet, Florian ; Brochard, Pierre ; Schilt, Stéphane ; Mileti, Gaetano

In: Journal of Physics: Conference Series, 2016, vol. 723, no. 1, p. 012034

We have developed a compact rubidium-stabilized laser system to serve as optical frequency reference in the 1.55-μm wavelength region, in particular for CO2 monitoring at 1572 nm. The light of a fiber-pigtailed distributed feedback (DFB) laser emitting at 1560 nm is frequency-doubled and locked to a sub-Doppler rubidium transition at 780 nm using a 2-cm long vapor glass cell. Part of...

Université de Neuchâtel

Compact rubidium-stabilized multi-frequency reference source in the 1.55-μm region

Matthey, Renaud ; Gruet, Florian ; Schilt, Stéphane ; Mileti, Gaetano

In: Optics Letters, 2015, vol. 40, no. 11, p. 2576-2579

Combining light modulation and frequency conversion techniques, a compact and simple frequency-stabilized optical frequency comb spanning over 45 nm in the 1.56- μm wavelength region is demonstrated. It benefits from the high-frequency stability achievable from rubidium atomic transitions at 780 nm probed in a saturation absorption scheme, which is transferred to the 1.56- μm spectral region...

Université de Neuchâtel

Demonstration of a high-performance pulsed optically pumped Rb clock based on a compact magnetron-type microwave cavity

Kang, Songbai ; Gharavipour, Mohammadreza ; Affolderbach, Christoph ; Gruet, Florian ; Mileti, Gaetano

In: Journal of Applied Physics, 2015/117//104510/1-5

We demonstrate a high-performance pulsed optically pumped (POP) Rb vapor-cell clock based on a magnetron-type microwave cavity of only 44 cm3 external volume. Using optical detection, an unprecedented 35% contrast of the Ramsey signal has been obtained. Both the signal-to-noise ratio (of 30 000) and the estimated shot-noise limit of 1.7×10-14τ-1/2 are at...

Université de Neuchâtel

Aging studies on micro-fabricated alkali buffer-gas cells for miniature atomic clocks

Abdullah, Salman ; Affolderbach, Christoph ; Gruet, Florian ; Mileti, Gaetano

In: Applied Physics Letters, 2015/106//163505/1-5

We report an aging study on micro-fabricated alkali vapor cells using neon as a buffer gas. An experimental atomic clock setup is used to measure the cell’s intrinsic frequency, by recording the clock frequency shift at different light intensities and extrapolating to zero intensity. We find a drift of the cell’s intrinsic frequency of (-5.2 ± 0.6) × 10-11/day and quantify...

Université de Neuchâtel

A miniature frequency-stabilized VCSEL system emitting at 795 nm based on LTCC modules

Gruet, Florian ; Vecchio, Fabrizio ; Affolderbach, Christoph ; Pétremand, Yves ; de Rooij, Nicolaas F ; Maeder, Thomas ; Mileti, Gaetano

In: Optics and Lasers in Engineering, 2013, vol. 51, no. 8, p. 1023–1027

We present a compact frequency-stabilized laser system locked to the Rubidium absorption line of a micro-fabricated reference cell. A printed circuit board (PCB) is used to carry all the components and part of the electronics, and low-temperature co-fired ceramic (LTCC) modules are used to temperature-stabilize the laser diode and the miniature Rubidium cell (cell inner dimensions: 5 mm diameter...