Publications related to Broadband Air-Coupled Ultrasound Emitter and Receiver Enable Simultaneous Measurement of Thickness and Speed of Sound in Solids

Reduced Training Data for Laser Ultrasound Signal Interpretation by Neural Networks

Romain Christophe Rémy Fleury, Janez Rus

The performance of machine learning algorithms is conditioned by the availability of training datasets, which is especially true for the field of nondestructive evaluation. Here we propose one reconfigurable specimen instead of numerous reference specimens ...

2024

Laser-based ultrasound inspection system

Romain Christophe Rémy Fleury, Janez Rus

A laser-based ultrasound inspection system comprising an object for inspection (1), a laser device for ultrasound generation (3a), a laser device for ultrasound detection (3b), and a coating arrangement (4) including a laser absorbing layer (4a) disposed o ...

2024

Inverse Problems in Pulse-Echo Ultrasound: Exploiting Coherence for Image Enhancement and Quantitative Imaging

Samuel Denys Beuret

Whereas pulse-echo ultrasound imaging relied on focused acoustic waves since its inception, the last two decades have seen the development of techniques based on unfocused waves, including ultrafast ultrasound imaging. In large part due to the emergence of ...

EPFL2024

Ultrasound inspection training system

Romain Christophe Rémy Fleury, Janez Rus

An ultrasound inspection training system comprising a test object (1), an ultrasound producing device (3) configured to generate ultrasonic signals in the test object and read ultrasonic response signals emitted from the test object, a property altering de ...

2024

Influence of ionization and cumulative effects on laser-induced crystallization in multilayer dielectrics

Yves Bellouard, Ruben Ricca, Victor Carle Adrien Boureau

Crystallization of amorphous layers has been demonstrated under various radically different laser-exposure conditions, including continuous wave (cw) and pulsed lasers. Here, we investigate the specific role of ionization in the crystallization of dielectr ...

2024

Femtosecond-laser direct-write photoconductive patterns on tellurite glass

Yves Bellouard, Gözden Torun, Anastasia Romashkina

We report the formation of arbitrary photoconductive patterns made of tellurium (Te) nanocrystals by exposing a tellurite (TeO2-based) glass to femtosecond laser pulses. During this process, Te/TeO2-glass nanocomposite interfaces with photoconductive prope ...

American Physical Society (APS)2024

On the interaction of femtosecond laser pulses with layered dielectric materials

Ruben Ricca

Materials properties are strictly dependent on their microstructure. The internal symmetries and the disposition of the constituting atoms of a material, which depend on its crystallographic structure, greatly affect its response to mechanical, electromagn ...

EPFL2023

Femtosecond laser-induced modifications and self-organization in complex glass systems

Gözden Torun

Ultrashort laser pulses, i.e., pulses emitted shorter than a picosecond, can tailor material properties by introducing permanent modifications locally in three dimensions. Remarkably, under a certain exposure condition, these modifications are accompanied ...

EPFL2023

Cavitation induced by pulsed and continuous-wave fiber lasers in confinement

Christophe Moser, Jan Krizek

Bubbles generated with lasers in liquids under confinement have been investigated for their potential use as the driving mechanism for liquid micro-jets in various microfluidic devices, such as needle-free jet injectors. Here, we report on the study of bub ...

ELSEVIER SCIENCE INC2023

In situ monitoring of femtosecond laser-induced modifications in dielectrics

Olivier Bernard

Over the last decades, the progress made in the generation of laser pulses shorter than a picosecond (10^-12 s) has allowed us to reach extreme optical power intensities exceeding 10^15 W cm^-2. This tremendous power has triggered an abundance of original ...

EPFL2023

All-glass miniature GHz repetition rate femtosecond laser cavity

Yves Bellouard, Antoine Maxime Delgoffe, Sargis Hakobyan, Saood Ibni Nazir

Free-space optics allows for design freedom and control, but miniaturization and manufacturability are limited. Here, we present a method for manufacturing complex miniaturized free-space optical systems that combines contactless femtosecond laser-activate ...

2023

Terahertz waveform synthesis in integrated thin-film lithium niobate platform

Jérôme Faist, Ileana-Cristina Benea-Chelmus, Francesca Fabiana Settembrini

Bridging the "terahertz gap" relies upon synthesizing arbitrary waveforms in the terahertz domain enabling applications that require both narrow band sources for sensing and few-cycle drives for classical and quantum objects. However, realization of custom ...

Nature Portfolio2023

Effect of femtosecond laser-induced high pressure on fused silica polymorphism

Arunkrishnan Radhakrishnan

High-pressure studies in silica are of great interest to earth and planetary sciences. Highpressure phases are rarely found in nature as a result of shock events like meteorite impacts or volcanic events in nature. Recreating these phases remains a challen ...

EPFL2022

A Wearable Ultrasound Interface for Prosthetic Hand Control

Xingchen Yang

Ultrasound can non-invasively detect muscle deformations and has great potential applications in prosthetic hand control. Traditional ultrasound equipment was usually too bulky to be applied in wearable scenarios. This research presented a compact ultrasou ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

Abnormal temperature dependent elastic properties of fused silica irradiated by ultrafast lasers

Yves Bellouard, Pieter Vlugter

Materials with thermal-invariant elastic properties are of interest for resonant device frequency and dimensional stability of precision devices. Here, we demonstrate that the temperature coefficient of elasticity (TCE) of amorphous silica can be locally r ...

2022

Ultrafast carrier and quasiparticle dynamics in strongly confined perovskite nanoplatelets

Etienne Christophe Socie

Over the past decade, lead halide perovskites (LHPs) have received considerable attention thanks to their impressive optoelectronic properties. Today, LHP-based devices are one of the most efficient single-junction solar cells, with power-conversion effici ...

EPFL2022

Wearable Ultrasound Interface for Prosthetic Hand Manipulation

Xingchen Yang

Ultrasound can non-invasively detect muscle deformations, which has great potential applications in prosthetic hand control. This research developed a miniaturized ultrasound device that could be integrated into a prosthetic hand socket. This compact syste ...

SPRINGER INTERNATIONAL PUBLISHING AG2022

A tunable femtosecond fiber laser source for multiphoton emission microscopy

Pierre-Marc Jean Marie Dansette

Second harmonic generation microscopy is used to image interfaces or non-centrosymmetric structures and molecules. Two-photon fluorescence microscopy can image molecules within cells without using markers. Thus those technics have lead to advances in our u ...

EPFL2021

Degradation study on molecules released from laser-based jet injector

Christophe Moser, Jan Krizek, Barbora Lavickova

Development of needle-free methods to administer injectable therapeutics has been researched for a few decades. We focused our attention on a laser-based jet injection technique where the liquid-jet actuation mechanism is based on optical cavitation. This ...

2021

Fabrication, Characterization, and Simulation of Glass Devices with AlN Thin-Film Transducers for Excitation of Ultrasound Resonances

Paul Muralt, Ramin Matloub Aghdam

We present the fabrication of 570-mu m-thick millimeter-sized soda-lime-silicate float-glass blocks with a 1-mu m-thick AlN thin-film piezoelectric transducer sandwiched between thin metallic electrodes and deposited on the top surface. The electromechanic ...

American Physical Society (APS)2021