A5028348135- Advanced Fiber Laser Technologies
- Spectroscopy and Laser Applications
- Laser Design and Applications
- Solid State Laser Technologies
- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- Laser-Matter Interactions and Applications
- Atmospheric Ozone and Climate
- Advanced Frequency and Time Standards
- Photonic Crystal and Fiber Optics
- Advanced Chemical Sensor Technologies
- Atmospheric and Environmental Gas Dynamics
- Advanced Fiber Optic Sensors
- Gas Sensing Nanomaterials and Sensors
- Advanced Photonic Communication Systems
- Cold Atom Physics and Bose-Einstein Condensates
- Analytical Chemistry and Sensors
- Mass Spectrometry Techniques and Applications
- Atomic and Subatomic Physics Research
- Optical Network Technologies
- Geophysics and Sensor Technology
- Water Quality Monitoring and Analysis
- Semiconductor Quantum Structures and Devices
- Thermography and Photoacoustic Techniques
- Advanced Sensor Technologies Research
Institut d'Histoire du Temps Présent
2023
Architecture, Territoire, Environnement
2023
University of Neuchâtel
2013-2022
Institut de Physique
2022
École Polytechnique Fédérale de Lausanne
1996-2017
Microsystems (United Kingdom)
2007-2010
Frequency fluctuations of lasers cause a broadening their line shapes. Although the relation between frequency noise spectrum and laser shape has been studied extensively, no simple expression exists to evaluate linewidth for spectra that does not follow power law. We present approach this with an approximate formula evaluation can be applied arbitrary spectral densities.
The synthesis of ultralow-noise microwaves is both scientific and technological relevance for timing, metrology, communications radio-astronomy. Today, the lowest reported phase noise signals are obtained via optical frequency-division using mode-locked laser frequency combs. Nonetheless, this technique ideally requires high repetition rates tight comb stabilisation. Here, a soliton microcomb with 14 GHz rate generated an ultra-stable pump used to derive microwave reference signal, absolute...
A theoretical model of wavelength modulation spectroscopy that uses a laser diode on Lorentzian absorption line is presented. This theory describes the general case current-modulated semiconductor laser, for which combined intensity and frequency with an arbitrary phase shift occurs. On basis this model, effect several parameters detected signals evaluated. Experimental measured CO2 by use 2-microm distributed-feedback are also presented validate analysis. These experimental results agree...
We investigate power-scaling of green-diode-pumped Ti:Sapphire lasers in continuous-wave (CW) and mode-locked operation. In a first configuration with total pump power up to 2 W incident onto the crystal, we achieved CW 440 mW self-starting mode-locking 200 average 68-fs pulses using semiconductor saturable absorber mirror (SESAM) as absorber. second 3 650 operation 450 58-fs Kerr-lens (KLM). The shortest pulse duration was 39 fs, which at 350 KLM. laser generates train repetition rates...
An optical sensor based on external-cavity quantum cascade laser (EC-QCL) was developed for simultaneous triple-species monitoring of CH4, N2O, and H2O vapor using off-beam quartz-enhanced photoacoustic spectroscopy (OB-QEPAS). The EC-QCL wavelength scanned over three neighboring absorption lines CH4 (1260.81 cm-1), N2O (1261.06 (1261.58 cm-1) by tuning the grating with a piezoelectric actuator. Molecular relaxation effects impacting generation QEPAS signals resulting from light molecules...
The frequency noise properties of commercial distributed feedback quantum cascade lasers emitting in the 4.6 μm range and operated cw mode near room temperature (277 K) are presented. measured power spectral density reveals a flicker dropping down to very low level <100 Hz(2)/Hz at 10 MHz Fourier is globally factor 100 lower than data recently reported for similar laser cryogenic temperature. This makes our good candidate realization mid-IR ultranarrow linewidth reference.
Laser frequency fluctuations can be characterized either comprehensively by the noise spectrum or in a simple but incomplete manner laser linewidth. A formal relation exists to calculate linewidth from spectrum, it is laborious apply practice. We recently proposed much simpler geometrical approximation applicable any arbitrary spectrum. Here we present an experimental validation of this using sources different spectral characteristics. For each them, measured both approximate and actual...
We report the first full stabilization of an optical frequency comb generated from a femtosecond diode-pumped solid-state laser (DPSSL) operating in 1.5-μm spectral region. The stability is characterized free-running and phase-locked operation by measuring noise properties carrier-envelope offset (CEO) beat, repetition rate, line at 1558 nm. high Q-factor semiconductor saturable absorber mirror (SESAM)-modelocked 1.5-µm DPSSL results low-noise CEO-beat, for which tight phase lock can be much...
We present the first stabilization of frequency comb offset from a diode-pumped gigahertz solid-state laser oscillator. No additional external amplification and/or compression output pulses is required. The reliably modelocked using SESAM and based on Yb:CALGO gain crystal. It generates 1.7-W average power pulse durations as short 64 fs at repetition rate 1 GHz. generate an octave-spanning supercontinuum in highly nonlinear fiber use standard f-to-2f carrier-envelope (CEO) fCEO detection...
Free-running dual-comb systems based on a single laser cavity are an attractive next generation technology for wide variety of applications. The high average power achievable by thin-disk (TDL) oscillators make this especially spectroscopy and sensing applications in the molecular fingerprint region enabled nonlinear frequency conversion. However, noise levels TDL oscillators, e.g., induced turbulent water-cooling disk, severe challenge spectroscopic In contribution, we confirm first time...
We present a new method for intra-cavity control of the carrier-envelope offset (CEO) frequency ultrafast lasers that combines high feedback bandwidth with low loss, nonlinearity, and dispersion. A semiconductor saturable-absorber mirror (SESAM) inside modelocked laser is optically pumped continuous-wave (cw) laser. In this way, SESAM acts as opto-optical modulator (OOM): optical power cw-laser corresponds to high-bandwidth modulation channel CEO control. experimentally verified femtosecond...
We demonstrate the first self-referenced full stabilization of a diode-pumped solid-state laser (DPSSL) frequency comb with GHz repetition rate. The Yb:CALGO DPSSL delivers an average output power up to 2.1 W typical pulse duration 96 fs and center wavelength 1055 nm. A carrier-envelope offset (CEO) beat signal-to-noise ratio 40 dB (in 10-kHz resolution bandwidth) is detected after supercontinuum generation f-to-2f interferometry directly from oscillator, without any external amplification...
We describe a radio-frequency (RF) discriminator, or frequency-to-voltage converter, based on voltage-controlled oscillator phase-locked to the signal under test, which has been developed analyze frequency noise properties of an RF signal, e.g., heterodyne optical beat between two lasers laser and comb. present detailed characterization this discriminator we compare it three other commercially available discriminators. Owing its large linear range 7 MHz, bandwidth 200 kHz floor below 0.01...
We report on the wavelength tuning dynamics in continuous-wave distributed feedback quantum cascade lasers (QCLs). The response for direct current modulation of two mid-IR QCLs from different suppliers was measured 10 Hz up to several MHz using ro-vibrational molecular resonances as frequency-to-intensity converters. Unlike output intensity, which can be modulated gigahertz, frequency-modulation bandwidth found order 200 kHz, limited by laser thermal dynamics. A non-negligible roll-off and a...
We phase-stabilized the carrier-envelope-offset (CEO) frequency of a SESAM modelocked Yb:CaGdAlO₄ (CALGO) thin disk laser (TDL) generating 90-fs pulses at center wavelength 1051.6 nm and repetition rate 65 MHz. By launching only 2% its output power into photonic crystal fiber, we generated coherent octave-spanning supercontinuum spectrum. Using standard f-to-2f interferometer for CEO detection, measured beats with 33 dB signal-to-noise ratio in 100 kHz resolution bandwidth. achieved tight...
Tailoring the properties of driving laser to need applications often requires compromises among stability, high peak and average power levels, pulse duration, spectral bandwidth. For instance, spectroscopy with optical frequency combs in extreme/visible ultraviolet region a near-IR laser, therefore power, duration few tens fs, maximal available Contrarily, parametric conversion efficiency is higher for pulses 100-fs range due temporal walk-off coating limitations. Here we suggest an approach...
This article reports on the characterization of cryogenic sapphire oscillators (CSOs), and first test a CSO in real field installation, where ultimate frequency stability continuous operation are critical issues, with no survey. Thanks to low-vibration liquid-He cryocooler design, Internet monitoring, significant effort engineering, these could bridge gap from an experiment fully reliable machine. The needs scheduled maintenance every 2 years, which is usual for devices. direct comparison...