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Concept

Faisceau gaussien

Publications associées (32)

Ultrafast Transverse Modulation of Free Electrons by Interaction with Shaped Optical Fields

Fabrizio Carbone, Thomas La Grange, Ivan Madan, Giovanni Maria Vanacore, Simone Gargiulo, Francesco Barantani, Alexey Sapozhnik, Veronica Leccese, Phoebe Marie Tengdin

Spatiotemporal electron-beam shaping is a bold frontier of electron microscopy. Over the past decade, shaping methods evolved from static phase plates to low-speed electrostatic and magnetostatic displays. Recently, a swift change of paradigm utilizing lig ...

AMER CHEMICAL SOC2022

Structured light engineering using a photonic nanojet

Toralf Scharf, Maryam Yousefi

In this Letter, we present the photonic nanojet as a phenomenon in a structured light generator system that is implemented to modify the source focal spot size and emission angle. The optical system comprises a microlens array that is illuminated by a focu ...

OPTICAL SOC AMER2021

System and method for high beam quality pulse generation in mode-locked multimode fiber lasers

Demetri Psaltis, Christophe Moser, Ugur Tegin

A system and method to generate ultrashort high beam quality pulses from spatio- temporally mode-locked multimode fiber laser are described. The invention relies on engineering the intra-cavity pulse propagation in a multimode laser cavity to shape the spa ...

2021

Structured light generation by refractive-diffractive micro optical array illuminators

Maryam Yousefi

Structured light generation having broad applications in different optical fields, is the topic of this thesis. Our structured light generation strategy is based on applying periodic microoptical elements at the refraction-diffraction limit, under a focuse ...

EPFL2021

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

Rapid melting and revitrification as an approach to microsecond time-resolved cryo-electron microscopy

Marcel Drabbels, Ulrich Lorenz, Pavel Olshin, Jonathan Mark Voss, Oliver Florian Harder

Proteins typically undergo dynamics on the microsecond to millisecond timescale, which is much faster than the time resolution of cryo-electron microscopy. Here, we propose a novel approach for microsecond time-resolved cryo-electron microscopy that involv ...

Elsevier2021

ON THE DESIGN AND OPTIMIZATION OF WIDE ANGLE DIFFRACTIVE OPTICAL ELEMENTS

Dong Cheon Kim

Diffractive optical elements (DOEs) which consist of microstructure surface relief permit the generation of the spatial distribution of light beams by using a single element. Due to their compact size, design flexibility, and mass productivity, they are us ...

EPFL2021

Transverse Noise, Decoherence, and Landau Damping in High-Energy Hadron Colliders

Sondre Vik Furuseth

High-energy hadron colliders are designed to generate particle collisions within specialized detectors. A higher number of collisions is achieved with high-quality beams of low transverse emittances, meaning a small transverse cross-section, and high inten ...

EPFL2021

Exploring nonlinearities in multimode optical fibers for lasers and computing

Ugur Tegin

Multimode optical fibers are the backbone of telecommunication and medical imaging. When light with high intensity travels through a multimode fiber, photons and matter start to interact and propa-gation becomes nonlinear. The nonlinear propagation of ligh ...

EPFL2021

Design and Thermal-Structural Analyses of Ancillary Components for the Optical Steering Mirror (M4) for the ITER ECH Upper Launcher

Timothy Goodman, René Chavan, Avelino Mas Sanchez, Matteo Vagnoni, Phillip Miguel Santos Silva

Each of the four ITER Electron Cyclotron Heating Upper Launcher (ECHUL) features eight transmission lines (TLs) that are used to inject 170-GHz microwave power into the plasma at a level of up to 1.31 MW (at the TL diamond window) per line. The millimeter ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2020

Adaptive Laser Welding Control: A Reinforcement Learning Approach

Giulio Masinelli, Silvio Zanoli

Despite extensive research efforts in the field of laser welding, the imperfect repeatability of the weld quality still represents an open topic. Indeed, the inherent complexity of the underlying physical phenomena prevents the implementation of an effecti ...

2020

Update of ion-optical system of neutral beam of Tokamak a Configuration Variable

Alexander Karpushov

An injector of fast deuterium atoms for plasma heating was designed and installed at the Tokamak a Configuration Variable (TCV). The neutral beam can deliver 1 MW power to the plasma in 2 s pulses. An ion beam of the injector is formed by a triode multisli ...

AMER INST PHYSICS2020