Publications associées à 1’000’000 resolved points along a Brillouin distributed fibre sensor

Investigating Novel Optical Fibres for More Advanced Distributed Optical Fibre Sensing

Malak Mohamed Hossameldeen Omar Mohamed Galal

The ever-growing need for distributed optical fibre sensors (DOFS) in numerous fields and applications demands continuous research towards the advancement of the existing sensing systems. The convenience in the field of DOFS lies in the several degrees of ...

EPFL2022

Enhanced Signal-Associated Noise in a φ-OTDR System

Luc Thévenaz, Malak Mohamed Hossameldeen Omar Mohamed Galal, Suneetha Sebastian

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 ...

2022

Distributed measurement of mode group effective refractive index difference in a few mode optical fibers

Luc Thévenaz, Zhisheng Yang, Alejandro Dominguez Lopez

The possibility to perform distributed measurements of the effective refractive index difference between distinct modes in few mode optical fibers is demonstrated using phase sensitive optical time domain reflectometry. Effective refractive index differenc ...

2022

An optimized protocol for assessing changes in mouse whole-brain activity using opto-fMRI

Christina Maria Grimm, Valerio Zerbi

Functional magnetic resonance imaging (fMRI) in mouse brain, paired with spatially and temporally defined manipulations, offers a powerful tool to causally explain the effect of specific neuronal activity on brain network dynamics. Here, we present an opti ...

ELSEVIER2022

Electrically driven source of time-energy entangled photons based on a self-pumped silicon microring resonator

Matteo Galli

Time-energy entangled photon pairs are fundamental resources for quantum communication protocols since they are robust against environmental fluctuations in optical fiber networks. Pair sources based on spontaneous four-wave mixing in silicon microring res ...

OPTICAL SOC AMER2020

Distributed optical fiber sensing based on frequency-scanned phase-sensitive optical time-domain reflectometry

Li Zhang

Unlike traditional sensing schemes which rely on discrete point sensors that perform measurements at predetermined positions, distributed optical fiber sensing is a general technique that enables to continuously gather information (typically temperature an ...

EPFL2020

Optical fibre sensing for fast hotspot detection in SFCLs

Bertrand Dutoit, Luc Thévenaz, Bertrand Dutoit, Arooj Akbar, Zhisheng Yang, Sheng Wang

The health monitoring of superconducting fault current limiters (SFCL) is important for their large-scale exploitation in HVDC grids protection. The intrinsic non-homogeneity of critical current along the superconductor length can cause localized points of ...

2020

Wavefront shaping and deep learning in fiber endoscopy

Eirini Kakkava

Fiber endoscopy plays an important role in the clinical diagnosis and treatment processes involved in modern medicine. Thin fiber probes can relay information from confined places in the human body that are inaccessible for conventional bulky microscopes. ...

EPFL2020

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

Distributed and dynamic strain sensing with high spatial resolution and large measurable strain range

Luc Thévenaz, Zhisheng Yang, Li Zhang, Malak Mohamed Hossameldeen Omar Mohamed Galal

A distributed and dynamic strain sensing system based on frequency-scanning phase-sensitive optical time domain reflectometry is proposed and demonstrated. By utilizing an RF pulse scheme with a fast arbitrary waveform generator, a train of optical pulses ...

2020

Performance analysis of the differential pulse-width pair Brillouin optical time domain analysis using the log normalized and linearly normalized gain

Luc Thévenaz, Simon Adrien Zaslawski, Zhisheng Yang

The performance of the differential pulse-width pair Brillouin optical time domain analysis (DPP-BOTDA) is evaluated experimentally using either the gain from log normalization or linear normalization for the subtraction of traces collected with pump pulse ...

SPIE2019

Optimizing Image Denoising for Long-Range Brillouin Distributed Fiber Sensing

Luc Thévenaz, Marcelo Alfonso Soto Hernandez

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 ...

IEEE Institute of Electrical and Electronics Engineers2018

Microscopy and digital light shaping through optical fibers

Damien Claude-Marie Loterie

Microscopy is an essential tool in medicine and biomedical research. Traditional microscopes rely on bulky optics, complicating their usage when studying live animal tissues. In addition, light cannot penetrate very far in most biological tissues due to sc ...

EPFL2017

Determination of the radiance of cylindrical light diffusers: design of a one-axis charge-coupled device camera-based goniometer setup

Georges Wagnières, Matthieu Philippe Emmanuel Zellweger, Blaise Lovisa, Andreas Pitzschke, Jenny Bertholet

A one-axis charge-coupled device camera-based goniometer setup was developed to measure the three-dimensional radiance profile ( longitudinal, azimuthal, and polar) of cylindrical light diffusers in air and water. An algorithm was programmed to project the ...

SPIE Society of Photo-optical Instrumentation Engineers2017

Multimode fiber optical imaging using wavefront control

Nicolino Stasio

Optical microscopy enables us to observe at high resolution and with a large field of view objects otherwise invisible for the naked eye. This is why it is becoming a fundamental tool in biology and in diagnostics, where observation at cellular level can t ...

EPFL2017

Distributed photothermal spectroscopy in microstructured optical fibers: towards high-resolution mapping of gas presence over long distances

Luc Thévenaz, Kenny Hey Tow

Chemical sensing using optical fibers is often challenging, as it is generally difficult to achieve strong interaction between the guided light and the analyte at the wavelength of interest for performing the detection. Despite this difficulty, many scheme ...

Optical Society of America2017

Going beyond 1000000 resolved points in a Brillouin distributed fiber sensor: theoretical analysis and experimental demonstration

Luc Thévenaz, Marcelo Alfonso Soto Hernandez, Andrey Denisov

Distributed fiber sensing possesses the unique ability to measure the distributed profile of an environmental quantity along many tens of kilometers with spatial resolutions in the meter or even centimeter scale. This feature enables distributed sensors to ...

Chinese Acad Sciences, Changchun Inst Optics Fine Mechanics And Physics2016

Coherent Rayleigh time domain reflectometry : novel applications for optical fibre sensing

Xin Lu

Owing to the advantages of the optical fibre, such as lightweight, small size, low cost and immunity to electromagnetic interferences, the fibre sensors have been applied in diverse fields and the scientific research on fibre sensing keeps improving to mee ...

EPFL2016

Two-photon fluorescence imaging through multicore fiber with digital phase conjugation

Demetri Psaltis, Christophe Moser, Nicolino Stasio, Donald Benjaman Conkey

We present near diffraction limited two photon fluorescence (TPF) imaging through a lensless, multi-core fiber (MCF) endoscope utilizing digital phase conjugation. The ultra-small size of MCFs make them desirable tools for imaging deep into the body. TPF i ...

Spie-Int Soc Optical Engineering2016

MilliKelvin resolution in cryogenic temperature distributed fibre sensing based on coherent Rayleigh scattering

Luc Thévenaz, Marcelo Alfonso Soto Hernandez, Xin Lu

The response of a distributed temperature sensor based on coherent Rayleigh scattering is experimentally studied in the temperature range from 77 K up to 300 K, using fibres with standard and ORMOCER coating. A precise and absolute frequency scan is perfor ...

SPIE2014