Université de Neuchâtel

Measurement of the magnetic field profile in the atomic fountain clock FoCS-2 using Zeeman spectroscopy

Devenoges, Laurent ; Di Domenico, Gianni ; Stefanov, André ; Jallageas, Antoine ; Morel, Jacques ; Südmeyer, Thomas ; Thomann, Pierre

In: Metrologia, 2017, vol. 54, no. 2, p. 239-246

We report the evaluation of the second-order Zeeman shift in the continuous atomic fountain clock FoCS-2. Because of its continuous operation and geometrical constraints, the methods used in pulsed fountains are not applicable. We use here time-resolved Zeeman spectroscopy to probe the magnetic field profile in the clock. Pulses of ac magnetic excitation allow us to spatially resolve the Zeeman...

Université de Neuchâtel

Ultra-stable microwave generation with a diode-pumped solid-state laser in the 1.5-µm range

Dolgovskiy, Vladimir ; Schilt, Stéphane ; Bucalovic, Nikola ; Di Domenico, Gianni ; Grop, Serge ; Dubois, Benoît ; Giordano, Vincent ; Südmeyer, Thomas

In: Applied Physics B : Lasers and optics, 2014, vol. 116, no. 3, p. 593-601

We demonstrate the first ultra-stable microwave generation based on a 1.5-µm diode-pumped solid-state laser (DPSSL) frequency comb. Our system relies on optical-to-microwave frequency division from a planar-waveguide external cavity laser referenced to an ultra-stable Fabry–Perot cavity. The evaluation of the microwave signal at ~10 GHz uses the transportable ultra-low-instability signal...

Université de Neuchâtel

Frequency Noise and Linewidth of Mid-infrared Continuous-Wave Quantum Cascade Lasers: An Overview

Schilt, Stéphane ; Tombez, Lionel ; Di Domenico, Gianni ; Hofstetter, Daniel

In: The Wonders of Nanotechnology: Quantum and Optoelectronic Devices and Applications (chapter 12), 2013, p. 261-287

Université de Neuchâtel

Wavelength tuning and thermal dynamics of continuous-wave mid-infrared distributed feedback quantum cascade lasers

Tombez, Lionel ; Cappelli, Francesco ; Schilt, Stéphane ; Di Domenico, Gianni ; Bartalini, Saverio ; Hofstetter, Daniel

In: Applied Physics Letters, 2013, vol. 103, no. 3, p. 1-5

We report on the wavelength tuning dynamics in continuous-wave distributed feedback quantum cascade lasers (QCLs). The wavelength tuning response for direct current modulation of two mid-IR QCLs from different suppliers was measured from 10 Hz up to several MHz using ro-vibrational molecular resonances as frequency-to-intensity converters. Unlike the output intensity, which can be modulated up...

Université de Neuchâtel

Linewidth of a quantum cascade laser assessed from its frequency noise spectrum and impact of the current driver

Tombez, Lionel ; Schilt, Stéphane ; Di Francesco, Joab F. ; Führer, Thorsten ; Rein, Benjamin ; Walther, Thomas ; Di Domenico, Gianni ; Hofstetter, Daniel ; Thomann, Pierre

In: Applied Physics B : Lasers and optics, 2012, vol. 109, no. 3, p. 407-414

We report on the measurement of the frequency noise properties of a 4.6-μm distributed-feedback quantum-cascade laser (QCL) operating in continuous wave near room temperature using a spectroscopic set-up. The flank of the R(14) ro-vibrational absorption line of carbon monoxide at 2196.6cm−1 is used to convert the frequency fluctuations of the laser into intensity fluctuations that...

Université de Neuchâtel

Noise properties of an optical frequency comb from a SESAM-modelocked 1.5 µm solid-state laser stabilized to the 10 -13 level

Schilt, Stéphane ; Dolgovskiy, Vladimir ; Bucalovic, Nikola ; Schori, Christian ; Stumpf, Max C. ; Di Domenico, Gianni ; Pekarek, Selina ; Oehler, Andreas E. H. ; Südmeyer, Thomas ; Keller, Ursula ; Thomann, Pierre

In: Applied Physics B : Lasers and optics, 2012, vol. 109, no. 3, p. 391-402

We present a detailed investigation of the noise properties of an optical frequency comb generated from a femtosecond diode-pumped solid-state laser operating in the 1.5-μm spectral region. The stabilization of the passively mode-locked Er:Yb:glass laser oscillator, referred to as ERGO, is achieved using pump power modulation for the control of the carrier envelope offset (CEO) frequency and by...

Université de Neuchâtel

Effect of the Carrier-Envelope-Offset Dynamics on the Stabilization of a Diode-Pumped Solid-State Frequency Comb

Bucalovic, Nikola ; Dolgovskiy, Vladimir ; Stumpf, Max C. ; Schori, Christian ; Di Domenico, Gianni ; Keller, Ursula ; Schilt, Stéphane ; Südmeyer, Thomas

In: Optics Letters, 2012, vol. 37, no. 21, p. 4428-4430

We investigate the dynamics of the carrier-envelope-offset (CEO) frequency, ƒ CEO, controlled by a pump current on the self-referencing of an optical frequency comb generated from a diode-pumped solid-state laser at 1.56 μm. We observe a reversal point in the tuning of ƒ CEO with the pump current. Between the low- and high-frequency region in the dynamic response of ƒ...

Université de Neuchâtel

New-generation cryogenic sapphire microwave oscillators for space, metrology and scientific applications

Giordano, Vincent ; Grop, Serge ; Dubois, Benoît ; Bourgeois, Pierre-Yves ; Kersalé, Yann ; Haye, Gregory ; Dolgovskiy, Vladimir ; Bucalovic, Nikola ; Di Domenico, Gianni ; Schilt, Stéphane ; Chauvin, Jacques ; Valat, David ; Rubiola, Enrico

In: Review of Scientific Instruments, 2012/83/8/085113/1-6

This article reports on the characterization of cryogenic sapphire oscillators (CSOs), and on the first test of a CSO in a real field installation, where ultimate frequency stability and continuous operation are critical issues, with no survey. Thanks to low-vibration liquid-He cryocooler design, Internet monitoring, and a significant effort of engineering, these oscillators could bridge the gap...

Université de Neuchâtel

Cross-influence between the two servo-loops of a fully-stabilized Er:fiber optical frequency comb

Dolgovskiy, Vladimir ; Bucalovic, Nikola ; Thomann, Pierre ; Schori, Christian ; Di Domenico, Gianni ; Schilt, Stéphane

In: Journal of the Optical Society of America B, 2012, vol. 29, no. 10, p. 2944-2957

We present a study of the impact of the cross-coupling between the two servo loops used to stabilize the repetition rate ƒ rep and the carrier-envelope offset (CEO) frequency ƒ CEO in a commercial Er:fiber frequency comb, based on the combination of experimental measurements and a model of the coupled loops. The developed theoretical model enables us to quantify the...