Publications by Luc Thévenaz | EPFL Graph Search

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Since the invention of optical fiber cable data transmission using light has become ubiquitous in the past years. Nonlinear optical effects, which are hardly noticed in our daily life, have become crucial and highly influential for the design and performan ...

We describe a low-power continuous-wave laser system for water-vapour sensing applications in the 935-nm region. The system is based on extended-cavity diode lasers and distributed-feedback lasers and delivers four single-mode frequency-stabilised optical ...

Modulation instability is thoroughly investigated and a simple analytical model for its power critically modifying the wave properties in terms of system parameters is derived and experimentally validated. The differences on the modulation instability gain ...

Optical fibre sensors based on stimulated Brillouin scattering have now clearly demonstrated their excellent capability for long-range distributed strain and temperature measurements. The fibre is used as sensing element and a value for temperature and/or ...

Among all the nonlinear effects stimulated Brillouin scattering offers the highest gain in solid materials and has demonstrated advanced photonics functionalities in waveguides. The large compressibility of gases suggests that stimulated Brillouin scat- te ...

We experimentally demonstrate an extremely simple technique to achieve pulse advancements in optical fibers by using both spontaneous amplified and stimulated Brillouin scattering. It is shown that the group velocity of a light signal is all-optically cont ...

The polarization properties of stimulated Brillouin scattering (SBS) amplification or attenuation in standard single-mode fibers are examined through vectorial analysis, simulation and experiment. Vector propagation equations for the signal wave, incorpora ...

This paper reports on a novel, simple yet reliable, unbalanced SOI Mach-Zehnder (M-Z) interferometer architecture based on 1.2 μm CMOS process and adapted post-processing for the waveguide sidewalls. The fabricated electro-optical device is based on multip ...

Linear and nonlinear two-dimensional image processing approaches are analyzed with the aim of removing noise from data acquired by distributed optical fiber sensors based on Brillouin optical time-domain analysis (BOTDA). The impact of the filter parameter ...

We experimentally demonstrate a novel technique to process broadband microwave signals, using all-optically tunable true time delay in optical fibers. The configuration to achieve true time delay basically consists of two main stages: photonic RF phase shi ...

Owing to their high sensitivity with respect to external measurands, Rayleigh-based distributed optical fiber sensors (DOFS) find their way into applications in many industrial and academic sectors. To further transcend the limit of these sensors in terms ...

This paper presents helpful expressions predicting the filling time of gaseous species inside photonic crystal fibres. Based on the theory of diffusion, our gas-filling model can be applied to any given fibre geometry or length by calculating diffusion coe ...

A method and apparatus serve to determine spectroscopically a concentration of ethanol in a test sample of an alcoholic aqueous beverage. The determination is based upon providing calibration data which establish a relation between (A) a plurality of transmission values of an electromagnetic radiation in the near infrared region, measured at a unique wavelength at which water is relatively opaque to the radiation while ethanol is relatively transparent thereto, of a plurality of calibration samples of the b

We demonstrate experimentally that it is possible to control optically the group velocity of an optical pulse as it travels along an optical fiber. To achieve this control we use the effect of Stimulated Brillouin Scattering. In our experiments we have ach ...

This paper proposes and experimentally validates a distributed temperature alarm system based on carbon dioxide (CO2)-filled 18 m side air-holes fiber (SAHF), interrogated through a conventional (incoherent) optical time-domain reflectometer (OTDR). Custom ...

A photoacoustic sensor using a laser diode emitting near 1532 nm in combination with an erbium-doped fibre amplifier has been developed for ammonia trace gas analysis at atmospheric pressure. NH3 concentration measurements down to 6 ppb and a noise-equival ...

Developed societies require more and more information for their safety and for their economic development. Recent disasters due to landslides, fires in tunnels and collapses of bridges are a source of serious concern on the part of the public which seeks f ...

In 2016, our research team proposed in an issue of Nature Communications1 the use of multidimensional signal processing, especially image denoising techniques, to improve the signal-to-noise ratio (SNR) of distributed optical ﬁbre sensors. The beneﬁts of t ...

A novel approach for resolution of contentions between asynchronous optical packets, exploiting a self-synchronizing mechanism by means of dynamic all-optical tunable delay line based on stimulated Brillouin scattering in fibers, is reported. Time delay between contending optical packets is mapped into the output timing of a contention-detecting pulse produced by the tunable delay line. The output pulse from the delay line triggers an integrated all-optical flip-flop that generates a synchronized gating sig

A couple of experiments are here presented to clarify the impact of slow light on light-matter interaction. The experiments are designed, so that the process generating slow light and the probed light-matter interaction only present a marginal cross-effect ...

Luc Thévenaz

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Generation and application of dynamic gratings in optical fibers using stimulated Brillouin scattering

Diode laser frequency stabilisation for water-vapour differential absorption sensing

Analytical model and experimental verification of the critical power for modulation instability in optical fibers

Recent progress towards centimetric spatial resolution in distributed fibre sensing

Intense Brillouin amplification in gas using hollow-core waveguides

Self-advanced fast light propagation in an optical fiber based on Brillouin scattering

Vector analysis of stimulated Brillouin scattering amplification in standard single-mode fibers

A novel CMOS SOI unbalanced Mach-Zehnder interferometer: from design and simulations to fabrication and characterization

Optimizing Image Denoising for Long-Range Brillouin Distributed Fiber Sensing

Broadband true time delay for microwave signal processing, using slow light based on stimulated Brillouin scattering in optical fibers

Enhanced Signal-Associated Noise in a φ-OTDR System

Optimized conditions for gas light interaction in photonic crystal fibres

Spectroscope method for determining the concentration of ethanol in beverages

Observation of pulse delaying and advancement in optical fibers using stimulated Brillouin scattering

Distributed Temperature Alarm System Based on Incoherent Optical Time-Domain Reflectometry and Side Air-Hole Optical Fibers

Ammonia trace measurements at ppb level based on near-IR photoacoustic spectroscopy

Brillouin Distributed Fibre Sensing: State of the Art and Perspectives

Evaluating measurement uncertainty in Brillouin distributed optical fibre sensors using image denoising

Application of Brillouin-Based Continuously Tunable Optical Delay Line to Contention Resolution Between Asynchronous Optical Packets

Enhancing the light-matter interaction using slow light: towards the concept of dense light