Publications de Flavien Gyger | EPFL Graph Search

New Avenues in Optical Fiber Sensing Using Gas

Luc Thévenaz, Flavien Gyger, Marcelo Alfonso Soto Hernandez, Li Zhang, Malak Mohamed Hossameldeen Omar Mohamed Galal, Yuting Yang

Gases turn out to be a very attractive medium for optical fiber sensing, showing highly flexible possibilities though widely unexploited so far. A new era opens for fiber sensing, exploiting the unprecedented potentialities of fluids. ...

Optica Publishing Group2023

Large evanescently-induced Brillouin scattering at the surrounding of a nanofibre

Luc Thévenaz, Flavien Gyger, Li Zhang

Brillouin scattering has been widely exploited for advanced photonics functionalities such as microwave photonics, signal processing, sensing, lasing, and more recently in micro- and nano-photonic waveguides. Most of the works have focused on the opto-acou ...

Nature Research2022

Waveguide and Gas: the Advent of a New Tool for Photonics

Luc Thévenaz, Flavien Gyger

The realisation of hollow-core fibres and nano-waveguides offers a unique opportunity to optimise the interactions between light and a gaseous medium. Stimulated Brillouin scattering is exploited to achieve unprecedented levels of amplification and to real ...

IEEE2021

Giant Brillouin Amplification in Gas Using Hollow-core Fiber

Luc Thévenaz, Flavien Gyger

Optical amplification in hollow core fibers has been achieved using stimulated Brillouin scattering directly in the gaseous medium. More than 50 dB optical gain is observed over 50 m of fiber using 200 mW of pump power. ...

Optical Society of America2021

Distributed fiber temperature alarm system based on thermodynamic phase transition

Luc Thévenaz, Flavien Gyger, Li Zhang

A novel temperature sensing mechanism is proposed for the first time, based on thermodynamic phase transitions of CO2 in hollow-core fibers. A fast, sensitive and distributed fiber temperature alarm system is demonstrated using this concept. ...

Optica Publishing Group2020

Giant Brillouin amplification in gas using hollow-core waveguides

Luc Thévenaz, Flavien Gyger

We report a strong Brillouin amplification in gas using hollow-core fibers, exceeding by 6 times the gain in solid silica fibers. A novel fiber laser using Brillouin lasing in gas has been demonstrated. ...

Optical Society of America2020

Intense Brillouin amplification in gas using hollow-core waveguides

Luc Thévenaz, Flavien Gyger

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 ...

Nature Publishing Group2020

Giant Brillouin Amplification in Gases

Luc Thévenaz, Flavien Gyger

In our work, we used stimulated Brillouin scattering directly in the gas medium (such as air) filling a hollow-core fiber to realize a massive optical amplification, by a factor of 200,000. ...

2020

Brillouin scattering in gas-filled hollow-core fibres

Flavien Gyger

Edward E. Hagenlocker and William G. Rado demonstrated Brillouin interaction in gas for the first time in 1965, right after the very first demonstrations of stimulated Brillouin scattering in solid materials. In their experiment, they used a megawatt pulse ...

EPFL2020

Observation of Stimulated Brillouin Scattering in Silicon Nitride Integrated Waveguides

Luc Thévenaz, Rui Ning Wang, Flavien Gyger, Tobias Kippenberg, Junqiu Liu, Arslan Sajid Raja, Jijun He

Silicon nitride (Si3N4) has emerged as a promising material for integrated nonlinear photonics and has been used for broadband soliton microcombs and low-pulse-energy supercontinuum generation. Therefore, understanding all nonlinear optical properties of S ...

2020

Observation of stimulated Brillouin scattering in silicon nitride integrated waveguides

Luc Thévenaz, Flavien Gyger, Tobias Kippenberg, Junqiu Liu, Arslan Sajid Raja, Jijun He

We report the first observation of backward stimulated Brillouin scattering in fully cladded Si3N4 waveguides. The intrinsic Brillouin gain at 25 GHz and the photoelastic constant are estimated to be 4 × 10−13 m/W and |p12| = 0.047 ± 0.004 respectively. ...

Optical Society of America2020

Large stimulated Brillouin scattering amplification in gases

Luc Thévenaz, Flavien Gyger

We exploit backward stimulated Brillouin scattering in gases to achieve unprecedented nonlinear optical amplification in fibers. The gain coefficient is 10 times larger than any reported nonlinear gain in gas-filled HC-PCF and 6 times larger than the large ...

SPIE2019

Massive nonlinear optical amplification in gas

Luc Thévenaz, Flavien Gyger

We achieve unprecedented nonlinear optical amplification in gas. The gain is 20 times larger than any reported nonlinear gain in gas-filled HC-PCF and 6 times larger than the largest nonlinear gain in standard silica single-mode fiber (SMF). Furthermore, o ...

2019

High spatial resolution and intrinsically strain-insensitive distributed temperature sensing based on stimulated Brillouin scattering in gas

Luc Thévenaz, Flavien Gyger

Temperature/strain cross sensitivity is a long-standing issue in Brillouin-based distributed sensors, impairing the reliability of such sensors. So far, all the proposed methods perform the discrimination by measuring two quantities showing distinct respon ...

SPIE2019

Large Brillouin Interaction in Hollow Core Fibers

Luc Thévenaz, Flavien Gyger

Brillouin gain is observed in hollow core fibers filled by standard gases at high pressure. This enables all interactions based on stimulated Brillouin scattering to be realized in hollow core fibers, such as amplification, optical signal processing and di ...

IEEE2019

Rayleigh-Based Distributed Optical Fiber Sensing Using Least Mean Square Similarity

Luc Thévenaz, Flavien Gyger, Zhisheng Yang, Li Zhang

Large frequency shift errors induced by cross-correlation are investigated in Rayleigh-based distributed sensing. A least mean square method is proposed to reduce those errors, thus increasing the reliability and extending the measurand range. ...

Optical Society of America2018

High Signal-to-Noise Ratio Stimulated Brillouin Scattering Gain Spectrum Measurement

Luc Thévenaz, Flavien Gyger, Marcelo Alfonso Soto Hernandez, Kenny Hey Tow, Zhisheng Yang

A technique to measure nonlinear processes, such as stimulated Brillouin scattering, with a very-high signal-to-noise ratio (SNR) is presented. Brillouin gain measurement with 77dB SNR is demonstrated over a 2m-long section of single-mode fiber. ...

Optical Society of America2018

Extending the sensing range of Brillouin optical time-domain analysis up to 325 km combining four optical repeaters

Luc Thévenaz, Sang Hoon Chin, Flavien Gyger

A novel scheme is proposed to extend the sensing range of Brillouin optical time-domain analyzers (BOTDA). Specially-designed erbium doped fiber amplifier (EDFA) repeaters are located every 65km fiber along the sensing cable to achieve a total sensing leng ...

SPIE2014