Publications associées à A high-reflectivity atom-focusing mirror stable at room temperature

Ultra low quantum decoherence nano-optomechanical systems

Thermal motion of a room-temperature mechanical resonator typically dominates the quantum backaction of its position measurement. This is a longstanding barrier for exploring cavity optomechanics at room temperature. In order to enter the quantum regime of ...

EPFL2022

Ferroelectric Effects Probed by in situ Transmission Electron Microscopy

Reinis Ignatans

Ferroelectric perovskite oxides are widely used in sensors, actuators and optical modulators and, at the same time, they show promise for implementation in future applications such as energy storage, memory and cooling devices. At the infancy of the discov ...

EPFL2022

Prototype mitre bends of the ex-vessel waveguide system for the ITER upper launcher: Thermal hydraulic simulations and experiments with off-center mm-wave beams

René Chavan, Timothy Goodman, Matteo Vagnoni, Anastasia Xydou, Humberto Torreblanca Quiroz

On ITER, long pulse gyrotrons are required as a power source for electron cyclotron heating (ECH) and current drive (CD). The microwaves are guided from the gyrotrons, which are placed far from the Tokamak, into the plasma by transmission lines (TLs) and a ...

2021

Challenges and Applications to Operando and In Situ TEM Imaging and Spectroscopic Capabilities in a Cryogenic Temperature Range

Martial Duchamp, Vasiliki Tileli, Reinis Ignatans

In this Account, we describe the challenges and promising applications of transmission electron microscopy (TEM) imaging and spectroscopy at cryogenic temperatures. Our work focuses on two areas of application: the delay of electron-beam-induced degradatio ...

AMER CHEMICAL SOC2021

Atomic-scale insights into the origin of rectangular lattice in nanographene probed by scanning tunneling microscopy

Shaoxian Li

We conducted atomic-scale scanning tunneling microscopy of a graphene nanosheet on graphite. In addition to a rhombus lattice representing the (root 3x root 3)R30 degrees superstructure, we resolved another quadrangle lattice similar to a rectangle in the ...

AMER PHYSICAL SOC2021

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

Electrochemical Stability of the Reconstructed Fe3O4(001) Surface

Klaus Kern

Establishing the atomic-scale structure of metal-oxide surfaces during electrochemical reactions is a key step to modeling this important class of electrocatalysts. Here, we demonstrate that the characteristic (root 2x root 2)R45 degrees surface reconstruc ...

Wiley-VCH Verlag GmbH2020

The effect of beryllium oxide on retention in JET ITER-like wall tiles

Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Yves Martin, Richard Pitts, Olivier Sauter, Henri Weisen, Stefano Coda, Marco Wischmeier, Jan Horacek, Yann Camenen, Jonathan Graves, Duccio Testa, Mikhail Maslov, Javier García Hernández, David Pfefferlé, Dalziel Joseph Wilson, Jonathan Marc Philippe Faustin, Federico Nespoli, Hamish William Patten, Bruno Emanuel Ferreira De Sousa Correia, Nicola Vianello, Antonio José Pereira de Figueiredo, Samuel Lanthaler, Liang Yao, Cristian Sommariva, Davide Galassi, Alessandro Pau, Yao Zhou, Otto Asunta, Bernhard Sieglin

Preliminary results investigating the microstructure, bonding and effect of beryllium oxide formation on retention in the JET ITER-like wall beryllium tiles, are presented. The tiles have been investigated by several techniques: Scanning Electron Microscop ...

Elsevier2019

Ultralow Dissipation Mechanical Resonators for Quantum Optomechanics

Tobias Kippenberg, Amir Hossein Ghadimi, Ryan Daniel Schilling, Dalziel Joseph Wilson, Sergey Fedorov, Nils Johan Engelsen, Alberto Beccari

We demonstrate dissipation dilution engineering techniques for ultralow dissipation mechanical resonators. The Si3N4 nanobeams show quality factors (Q) as high as 800 million and Q x f exceeding 10(15) Hz-both records at room temperature. (C) 2019 The Auth ...

IEEE2019

Plasma cleaning of beryllium coated mirrors

Cleaning systems of metallic first mirrors are needed in more than 20 optical diagnostic systems from ITER to avoid reflectivity losses. Currently, plasma sputtering is considered as one of the most promising techniques to remove deposits coming from the m ...

Iop Publishing Ltd2016

Influence of root characteristics and soil variables on the uprooting mechanics of Avena sativa and Medicago sativa seedlings

Benoît Crouzy, Paolo Burlando, Paolo Perona, Katharina Maria Edmaier

The success of seedlings and rejuvenated woody debris growing on river bedforms depends on the resistance to uprooting by flow provided by their simple root architecture. Avena sativa and Medicago sativa seedlings were used in flume experiments as prototyp ...

Wiley-Blackwell2014

The effect of bias in gas temperature measurements on the control of a Solid Oxide Fuel Cells system

Daniel Favrat, Jan Van Herle, Leonidas Tsikonis, Joel Albrektsson

In this paper the effect of systematic errors in gas temperature measurements on the thermal control of a Solid Oxide Fuel Cell system is demonstrated. Three control schemes were tested under two different conditions. First, the real gas temperature at the ...

Elsevier Science Bv2014

New diagnostics for density measurement on Frascati Tokamak upgrade

Fabio Avino, Anton Petrov

In FTU, density profile is measured with two new diagnostics: a CO2/CO scanning interferometer and a time-of-flight radar (denominated refractometer). The first, using two scanning beams, can provide a plasma density profile every 62.5 mu s. Two lasers (CO ...

Elsevier Science Bv2013

Further study on iterative control loop for aberration correction in imaging systems with single mode fibre aperture

An iterative control system was designed for compensation of wavefront aberration utilizing a micromachined deformable mirror through simulated annealing algorithm. 37 elements within a deformable mirror are controlled individually in a closed-loop to maxi ...

Natl Inst Optoelectronics2013

A dual-axis pointing mirror with moving-magnet actuation

Nico de Rooij, Wilfried Noell, Caglar Ataman, Sébastien Lani

A large-aperture and large-angle MEMS-based 2D pointing mirror is presented. The device is electromagnetically actuated by a moving-magnet/stationary-coil pair and potentially suited for high power laser beam shaping and beam pointing applications, such as ...

Institute of Physics2013

A 10 mK scanning tunneling microscope operating in ultra high vacuum and high magnetic fields

Klaus Kern, Markus Etzkorn, Maximilian Assig

We present design and performance of a scanning tunneling microscope (STM) that operates at temperatures down to 10 mK providing ultimate energy resolution on the atomic scale. The STM is attached to a dilution refrigerator with direct access to an ultra h ...

Amer Inst Physics2013

Large micromirror array for generating programmable slit masks for Multi-Object Spectroscopy

Nico de Rooij, Michael David Canonica, Wilfried Noell

Multi-object spectroscopy (MOS) is a powerful tool for space and ground-based telescopes for the study of the formation and evolution of galaxies. This technique requires a programmable slit mask for astronomical object selection. We are engaged in a Europ ...

Spie-Int Soc Optical Engineering2012

A hybrid on-chip optomechanical transducer for ultrasensitive force measurements

Tobias Kippenberg, Emanuel Gavartin

Nanoscale mechanical oscillators(1) are used as ultrasensitive detectors of force(2), mass(3) and charge(4). Nanomechanical oscillators have also been coupled with optical and electronic resonators to explore the quantum properties of mechanical systems(5) ...

Nature Publishing Group2012

Terephthalic acid adsorption on Si(111)-(root 3x root 3)-Bi surfaces: Effect of Bi coverage

Klaus Kern, Theresa Lutz, Giovanni Costantini

The influence of the density of metallic atoms on the formation of supramolecular structures onto Si surface alloys is investigated by scanning tunneling microscopy. Terephthalic acid (TPA) adsorption experiments are performed on the Si(111) alpha- and bet ...

2011

Large Hybrid High Precision MEMS Mirrors

Dara Zaman Bayat

This thesis presents the design and microfabrication technology of a tip-tilt, 2 degree of freedom "mirror system" made out of Silicon On Insulator (SOI) wafers with two movable mirrors that have diameter of 10 mm. The system was intended for precise beam ...

EPFL2011