Publications associées à Chirurgie au laser

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

All-glass miniature GHz repetition rate femtosecond laser cavity

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

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

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

Enhancement of Pressure-Sensitive Adhesive by CO2 Laser Treatment

Dario Floreano, Yegor Piskarev, Jun Shintake, Vivek Ramachandran, Michael Dickey, Jianhang Yang

Pressure-sensitive adhesives (PSAs) are polymeric films that can be adhered to and detached from surfaces without leaving residue. Researchers are looking to enhance the bond strength between PSAs and different substrates. It can be achieved by tuning PSA' ...

2022

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

Creating and controlling exceptional points of non-Hermitian Hamiltonians via homodyne Lindbladian invariance

Fabrizio Minganti

The exceptional points (EPs) of non-Hermitian Hamiltonians (NHHs) are spectral degeneracies associated with coalescing eigenvalues and eigenvectors, which are associated with remarkable dynamical properties. These EPs can be generated experimentally in ope ...

AMER PHYSICAL SOC2022

Laser treatment systems and methods for in-situ laser shock peening (lsp) treatment of parts during production thereof by a selective laser sintering or melting (sls/slm) process, and additive manufacturing systems and methods implementing the same

Roland Logé, Nikola Kalentics

There is described, in accordance with a first aspect of the invention, a laser treatment system and method for, in particular, imparting beneficial residual stresses into a desired part (P) during production thereof by a Selective Laser Sintering or Melti ...

2021

Electrically pumped shot-noise limited class A VECSEL at telecom wavelength

Elyahou Kapon, Alexandru Mereuta, Andrei Caliman

Class A shot-noise limited operation is achieved in an electrically pumped vertical external cavity surface emitting laser (VECSEL), opening the way for integration of such peculiar noiseless laser oscillation in applications where low power consumption an ...

2021

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

Liouvillian spectral collapse in the Scully-Lamb laser model

Fabrizio Minganti

Phase transitions of thermal systems and the laser threshold were first connected more than forty years ago. Despite the nonequilibrium nature of the laser, the Landau theory of thermal phase transitions, applied directly to the Scully-Lamb laser model (SL ...

AMER PHYSICAL SOC2021

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

Critical crystallization properties of an industrial-grade Zr-based metallic glass used in additive manufacturing

Roland Logé, Jamasp Jhabvala, Navid Sohrabi

The major challenge to overcome when processing metallic glasses (MGs) is to avoid crystallization. Therefore, time-temperature-transformation (TTT) diagrams are used, but they are often derived from experiments in which heating or cooling rates are limite ...

2021

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

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

Ultrafast carbothermal reduction of silica to silicon using a CO2 laser beam

Jaeki Jeong

We report the extraction of silicon via a carbothermal reduction process using a CO2 laser beam as a heat source. The surface of a mixture of silica and carbon black powder became brown after laser beam irradiation for a few tens of seconds, and clear peak ...

NATURE RESEARCH2020

Elastic properties of self-organized nanogratings produced by femtosecond laser exposure of fused silica

Yves Bellouard, Pieter Vlugter

Under certain exposure conditions, a femtosecond laser beam focused in the bulk of fused silica leads to the formation of self-organized structures consisting of a series of “nanolayers,” parallel to one another. Remarkably, this laser-induced nanoscale an ...

2020

An effective rule for translating optimal selective laser melting processing parameters from one material to another

Roland Logé, Jamasp Jhabvala, Eric Boillat, Rita Drissi Daoudi, Hossein Ghasemi Tabasi, Toni Ivas

Selective Laser Melting (SLM) or Laser Powder Bed Fusion (L-PBF) is the most studied laser-based additive manufacturing process for metals and alloys. One important issue in SLM is the time-consuming identification of a process window leading to quasi full ...

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

Physics of optically driven nanojunctions

Philippe Andreas Rölli

Recent years have seen spectacular developments in the domain of nano-optics. Alongside the well-known techniques of super-resolution microscopy progress in nanofabrication has enabled important improvements in the fields of optical imaging and spectros ...

EPFL2020