Publications related to Dark fibre

Spun fibres: a quasi circularly birefringent medium

Luc Thévenaz, Ana Gabriela Correa Mena, Xu Cheng

A simplified model describing the polarisation characteristics of spun fibres is proposed, aiming at determining how close to a circularly birefringent medium such a fibre is. This is of crucial importance regarding the interest of such a medium for magnet ...

SPIE2023

A Kilometre-range Distributed Relative Humidity Fibre Sensor

Tiago Filipe Pimentel Das Neves

Fibre optics sensors have been identified as very good candidates for environmental monitoring inside the silicon detectors operated at CERN's Large Hadron Collider. The objective of this dissertation is the development of a Relative Humidity (RH) distribu ...

EPFL2022

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

A fibre optic and machine learning based health monitoring system for superconducting power applications in modern supergrids

Arooj Akbar

The concerns for climate change and the transition to renewables is increasing the relevance of superconducting applications: High Temperature Superconductor (HTS) cables for efficient power transmission, superconducting magnets for nuclear fusion, superco ...

EPFL2022

Genetic-optimised aperiodic code for distributed optical fibre sensors

Luc Thévenaz, Marcelo Alfonso Soto Hernandez, Zhisheng Yang, Simon Adrien Zaslawski, Sheng Wang, Jian Wu

Distributed optical fibre sensors deliver a map of a physical quantity along an optical fibre, providing a unique solution for health monitoring of targeted structures. Considerable developments over recent years have pushed conventional distributed sensor ...

Nature Research2020

Optical fibre sensing for fast hotspot detection in SFCLs

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

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

Microresonator-based solitons for massively parallel coherent optical communications

Tobias Kippenberg, Victor Brasch, Maxim Karpov, Martin Hubert Peter Pfeiffer, Arne Kordts, Miles Henry Anderson

Solitons are waveforms that preserve their shape while propagating, as a result of a balance of dispersion and nonlinearity(1,2). Soliton-based data transmission schemes were investigated in the 1980s and showed promise as a way of overcoming the limitatio ...

Nature Publishing Group2017

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

1’000’000 resolved points along a Brillouin distributed fibre sensor

Luc Thévenaz, Marcelo Alfonso Soto Hernandez, Andrey Denisov

The challenge to resolve a record of one million points along a single optical fibre is demonstrated using a Brillouin distributed fibre sensor. The proposed system is based on a phase-correlation technique combined with a temporal pump gating, making poss ...

SPIE2014

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

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

Optical Gas-Phase Frequency References Based on Photonic Crystal Technology : Impact of Slow Light on Molecular Absorption

Isabelle Dicaire

Optical frequency references are devices providing well-defined and stable optical frequency responses to incoming radiation for applications such as high-precision spectroscopy and optical fibre communications. To stabilise the emission frequency of laser ...

EPFL2012

Application des réseaux de Bragg à la détermination des déformations distribuées dans les matériaux composites

The behaviour of brittle matrix fibre reinforced-composites is dependent of the properties of its constituents (fibre, matrix and fibre-matrix interface) and is affected by the mechanical and environmental loads. The fracture of a unidirectional composite ...

EPFL2009

Seepage and settlement monitoring for earth embankment dams using fully distributed sensing along optical fibers

Luc Thévenaz, Yao Zhou, Pingyu Zhu

A method for seepage and settlement monitoring in earth embankment dams using fully distributed sensing along optical fibres is proposed. A model is developed for simulating and monitoring seepage and settlement systems. This model relates the strains and ...

SPIE2008

Advanced trends in nonlinear optics applied to distributed optical-fibre sensors

Dario Alasia

The distributed optical-fibre sensors based on the properties of Brillouin scattering is the central object of this thesis. In the past decade, optical fibres have gained a large interest as sensors: attractive solutions based on the non-linear stimulated ...

EPFL2006

Capteur chimique à fibres optiques pour la mesure des ions chlore dans le béton à un stade précoce

Francine Laferrière

In the national and worldwide context, countless reinforced concrete structures are in an advanced state of deterioration. A principal cause of such degradation is chloride induced corrosion of reinforcement bars. This phenomenon is accentuated in countrie ...

EPFL2005

Reliability and lifetime of optical fibres and fibre bragg gratings for metrology and telecommunications

This thesis presents new developments on the different intrinsic failure mechanisms of silica optical fibres and fibre Bragg gratings with regard to applications in the fields of telecommunications and metrology. These failure mechanisms are mainly due to ...

EPFL2001