Publications de Kenny Hey Tow | EPFL Graph Search

Distributed Fibre Optic Thermo-hygrometer for Monitoring the Concrete Curing

Luc Thévenaz, Kenny Hey Tow, Tiago Filipe Pimentel Das Neves

The moisture content in concrete is a critical parameter for most of the degradation processes such as shrinkage and cracking. In this paper, we present the first kilometre-range thermo-hygrometer for monitoring the concrete curing. ...

Optica Publishing Group2022

Fiber Bragg grating-based thermometer for drill bit temperature monitoring

Luc Thévenaz, Kenny Hey Tow

The temperature measurement of a drill bit during an implantology drilling process is proposed by using a fiber Bragg grating fitted inside the drill bit. Due to the rotational nature of the drilling process, a free-space fiber-optic rotary joint is used f ...

2019

A kilometre-range distributed relative humidity sensor

Luc Thévenaz, Li Zhang, Kenny Hey Tow, 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. In this study, we present the results from the first highly sensitive relative humidity di ...

SPIE2019

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

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

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

Distributed hydrostatic pressure measurement using phase-OTDR in a highly birefringent photonic crystal fibre

Luc Thévenaz, Li Zhang, Kenny Hey Tow

We demonstrate a distributed hydrostatic pressure measurement based on phase-sensitive optical time-domain reflectometry in a highly birefringent photonic crystal fibre with a 0.4 bar pressure resolution and a 10 cm spatial resolution. ...

Optical Society of America2018

Exploring the use of native spider silk as an optical fibre for chemical sensing

Luc Thévenaz, Kenny Hey Tow, Isabelle Dicaire, Desmond Chow Ming Chia

A spider uses up to seven different types of silk, all having specific functions, as building material, weapon and sensory organ to detect the presence of preys on its web. Recently, scientists have put under the limelight the extraordinary properties of t ...

IEEE Institute of Electrical and Electronics Engineers2018

From Spider Webs to a Biomimetic Optical Fibre Sensor

Luc Thévenaz, Kenny Hey Tow, Isabelle Dicaire, Desmond Chow Ming Chia

Can we use spider silk threads as natural, biological optical fibre sensors? In this communication, we will see how we can harness the optical properties of spider dragline silk and use it for sensing. ...

2018

CO2-filled Hollow-Core Fiber Reference Gas Cells for Laser Frequency Stabilization at 2 um

Luc Thévenaz, Kenny Hey Tow

We present different configurations of compact CO2 reference gas cells based on hollow-core photonic crystal fibers (HC-PCF) for laser frequency stabilization at 2 um. Gaseous helium permeation through the silica fiber walls was used to fabricate low-press ...

2018

All-fiber molecular frequency reference at 2 μm based on a versatile laser modulation sideband locking and a hollow-core fiber gas cell

Luc Thévenaz, Kenny Hey Tow

Sensing of atmospheric trace gases is crucial for climate monitoring and to predict global climate changes. The required global coverage and spatial resolution have driven the studies of space-borne differential absorption lidar (DIAL) instruments to remot ...

IEEE2017

Distributed photothermal measurements of gas presence along holey optical fibers

Luc Thévenaz, Kenny Hey Tow

Chirped-pulse phase-sensitive optical time domain reflectometry has shown a remarkable performance when applied to dynamic measurements of strain and temperature, recently reaching ranges of several kilometers while interrogating the fiber at acoustic freq ...

SPIE2017