Publications associées à Conducting polymer microactuators operating in air

On the interaction of femtosecond laser pulses with layered dielectric materials

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

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

Formation Mechanism of Elemental Te Produced in Tellurite Glass Systems by Femtosecond Laser Irradiation

Yves Bellouard, Gözden Torun

The formation of elemental trigonal tellurium (t-Te) on tellurite glass surfaces exposed to femtosecond laser pulses is discussed. Specifically, the underlying elemental crystallization phenomenon is investigated by altering laser parameters in common tell ...

Wiley2023

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

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

Intraocular Lens Refractive Index and Its Impact on External Surface Reflections

Georges Wagnières

PURPOSE: To determine and compare the origin of the external surface reflections produced by commonly used intraocular lenses (IOLs). ...

SLACK INC2021

Self-Injection Locking of a Gain-Switched Laser Diode

Andrey Voloshin

We experimentally observe a self-injection locking regime of the gain-switched laser to a high-Q optical microresonator. We reveal that the comb generated by the gain-switched laser experiences a dramatic reduction of comb-teeth linewidths in this regime. ...

American Physical Society (APS)2021

Time-Resolved Transmission Electron Microscopy: Instrumentation and Applications

Pavel Olshin

In recent decades, in situ electron microscopy has attracted considerable attention. The method enables real time observations of the transformations of nanoparticles under various stimuli with atomic spatial resolution. Time-resolved electron microscopy a ...

EPFL2021

The fragmentation mechanism of gold nanoparticles in water under femtosecond laser irradiation

Marcel Drabbels, Ulrich Lorenz, Pavel Olshin, Gabriele Bongiovanni, Jonathan Mark Voss, Chengcheng Yan

Plasmonic nanoparticles in aqueous solution have long been known to fragment under irradiation with intense ultrafast laser pulses, creating progeny particles with diameters of a few nanometers. However, the mechanism of this process is still intensely deb ...

2021

Nanosecond pulsed laser-processing of CVD diamond

Patrik Willi Hoffmann, Marco Cantoni, Sébastien Equis

This work considers the resulting material structural effects of laser-processing chemical vapor deposited (CVD) diamond. The utilized 532 nm wavelength laser had a pulse duration of 40 ns together with a spot diameter of ca. 40 mu m. The effect of cutting ...

ELSEVIER SCI LTD2020

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

Selective femtosecond laser ablation via two-photon fluorescence imaging through a multimode fiber

Demetri Psaltis, Christophe Moser, Damien Claude-Marie Loterie, Donald Benjaman Conkey, Marilisa Romito, Eirini Kakkava

We demonstrate the ability of a multimode fiber probe to provide two-photon fluorescence (TPF) imaging feedback that guides the femtosecond laser ablation (FLA) in biological samples for highly selective modifications. We implement the system through the p ...

OPTICAL SOC AMER2019

Two-photon imaging and selective laser ablation of Cochlea hair cells through a multimode fiber probe

Demetri Psaltis, Christophe Moser, Damien Claude-Marie Loterie, Marilisa Romito, Eirini Kakkava

We demonstrate multimode fiber probe that accomodates dual modality properties for high power ultrashort pulse delivery. A commercially available multimode graded-index (GRIN) fiber is used for two-photon imaging and/or femtosecond laser ablation of Cochle ...

SPIE-INT SOC OPTICAL ENGINEERING2019

Development and performance evaluation of a high mass resolution time of flight laser ablation ionisation mass spectrometer

Reto Wiesendanger

This thesis contributes to the field of analytical chemistry of solid samples by introducing a new instrument with unprecedented performance characteristics and analytical capabilities. The instrument is based on the laser ablation and ionisation time-of-f ...

EPFL2019

In Situ Observation of Coulomb Fission of Individual Plasmonic Nanoparticles

Marcel Drabbels, Ulrich Lorenz, Pavel Olshin, Jonathan Mark Voss

Reshaping plasmonic nanoparticles with laser pulses has been extensively researched as a tool for tuning their properties. However, in the absence of direct observations of the processes involved, important mechanistic details have remained elusive. Here, ...

2019

Non-contact femtosecond laser-based methods for investigating glass mechanics at small scales

Christos Edouardos Athanasiou

With the progress made in miniaturizing systems over the last decades, understanding materialsâ behavior at small scales has become a necessity. In this context, glass behavior has remained largely unknown, partly for technological reasons and partly due ...

EPFL2018

A device and method for increased light transmission through cochlear bone by laser ablation for in situ intracochlear imaging

Demetri Psaltis, Donald Benjaman Conkey, Marilisa Romito

A method for visualizing structures inside a cochlea, comprising the steps of irradiating a cochlear bone with a first laser light to ablate portions of the cochlear bone, to form a thinned area of the cochlear bone, and imaging intracochlear structures by ...

2017

Laser-Induced Transition between Nonlinear and Linear Resonant Behaviors of a Micromechanical Oscillator

Yves Bellouard, Tao Yang

We investigate both theoretically and experimentally a laser-based controlled tuning of the nonlinear behaviors of a single mechanical resonator. Thanks to localized three-dimensional modifications induced by femtosecond-laser irradiation, a Duffing-like o ...

American Physical Society (APS)2017

3D monolithic dielectrophoretic actuators and resonators written by femtosecond laser

Tao Yang

The last few decades have witnessed exciting advances in micro-opto-electro-mechanical systems (MOEMS) including revolutionary development of fabrication processes and an ever increasing expansion of their domain of applications. In parallel, femtosecond l ...

EPFL2017