Publications associées à Holographie

Wavelength-stabilized figure-of-9 thulium-doped all-fiber laser emitting 560 fs pulses

Camille Sophie Brès, Moritz Bartnick, Gayathri Bharathan

We demonstrate a figure-of-9 all-fiber thulium-doped laser (TDFL) that generates 560 fs long pulses at 1948 nm wavelength. In order to achieve self-starting passive mode-locking, we utilize an in-fiber Faraday rotator to induce a nonreciprocal phase shift. ...

Iop Publishing Ltd2024

3D diffractive optics for linear interconnects and nonlinear processing

Niyazi Ulas Dinç

The optical domain presents potential avenues for enhancing both computing and communication due to its inherent properties of bandwidth, parallelism, and energy efficiency. This research focuses on harnessing 3-Dimensional (3D) diffractive optics for nove ...

EPFL2024

Reconstruction of Angstrom resolution exit-waves by the application of drift-corrected phase-shifting off-axis electron holography

Thierry Meyer, Victor Carle Adrien Boureau

Phase-shifting electron holography is an excellent method to reveal electron wave phase information with very high phase sensitivity over a large range of spatial frequencies. It circumvents the limiting trade-off between fringe spacing and visibility of s ...

Elsevier2023

On A Special Symmetry In The Dynamics Of Complex Systems In A Holographic-Type Perspective

Maria-Alexandra Paun

By operating with the Scale Relativity Theory in the dynamics of complex systems, we can achieve a description of these complex systems through a holographic-type perspective. Then, gauge invariances of a Riccati-type become functional in complex system dy ...

UNIV POLITEHNICA BUCHAREST, SCI BULL2023

Automated Dual-Mode Cell Monitoring To Simultaneously Explore Calcium Dynamics and Contraction-Relaxation Kinetics within Drug-Treated Stem Cell-Derived Cardiomyocytes

Gerardo Turcatti, Benjamin Rappaz, Bokyoung Kim, Pierre Marquet

This manuscript proposes a new dual-mode cell imaging system for studying the relationships between calcium dynamics and the contractility process of cardiomyocytes derived from human-induced pluripotent stem cells. Practically, this dual-mode cell imaging ...

AMER CHEMICAL SOC2023

Third-harmonic generation monitoring of femtosecond-laser-induced in-volume functional modifications

Christian Enz, Yves Bellouard, Assim Boukhayma, Andrea Kraxner, Olivier Bernard

During the last two decades, ultrafast in-volume laser-based processing of transparent materials has emerged as a key 3D-printing method for manufacturing a variety of complex integrated photonic devices and micro-parts. Yet, identifying suitable laser pro ...

2023

Optical Diffraction Tomography Using Nearly In-Line Holography with a Broadband LED Source

Demetri Psaltis, Abhijit Roy, Ahmed Ayoub

We present optical tomography methods for a 3D refractive index reconstruction of weakly scattering objects using LED light sources. We are able to record holograms by minimizing the optical path difference between the signal and reference beams while sepa ...

MDPI2022

Search for long-lasting electronic coherence using on-the-fly ab initio semiclassical dynamics

Jiri Vanicek, Alan Scheidegger, Nikolay Golubev

Using a combination of high-level ab initio electronic structure methods with efficient on-the-fly semiclassical evaluation of nuclear dynamics, we performed a massive scan of small polyatomic molecules searching for a long-lasting oscillatory dynamics of ...

AIP Publishing2022

Amplitude and phase reconstruction for Low-Energy Electron Holography of individual proteins

Hannah Julia Ochner

Single-molecule imaging methods are of importance in structural biology, and specifically in the imaging of proteins, since they can elucidate conformational variability and structural changes that might be lost in imaging methods relying on averaging proc ...

EPFL2022

Off-axis electron holography for the direct visualization of perpendicular shape anisotropy in nanoscale 3D magnetic random-access-memory devices

Victor Carle Adrien Boureau

Perpendicular shape anisotropy (PSA) and double magnetic tunnel junctions (DMTJs) offer practical solutions to downscale spin-transfer-torque Magnetic Random-Access Memory (STT-MRAM) beyond 20 nm technology nodes, while retaining their thermal stability an ...

AIP Publishing2022

Bragg edge tomography characterization of additively manufactured 316L steel

Roland Logé, Christian Leinenbach, Nikola Kalentics, Markus Strobl, Efthymios Polatidis

In this work we perform a neutron Bragg edge tomography of stainless steel 316L additive manufacturing samples, one as built via standard laser powder bed fusion, and one using the novel three-dimensional (3D) laser shock peening technique. First, we consi ...

AMER PHYSICAL SOC2022

Ultrafast laser interaction with transparent multi-layer SiO2/Si3N4 films

Yves Bellouard, Victor Carle Adrien Boureau, Ruben Ricca

We investigate the use of ultrafast lasers exposure to induce localized crystallization and elemental redistribution in amorphous dielectric multi-layers, composed of alternating Si3N4 and SiO2 layers of sub-micrometer thickness. Specifically, we report on ...

2021

Highly spatially resolved mapping of the piezoelectric potentials in InGaN quantum well structures by off-axis electron holography

Victor Carle Adrien Boureau

The internal fields in 2.2nm thick InGaN quantum wells in a GaN LED structure have been investigated by using aberration-corrected off-axis electron holography with a spatial resolution of better than 1nm. To improve the spatial resolution, different types ...

2020

All-Dielectric Programmable Huygens' Metasurfaces

Hatice Altug, Andreas Tittl, Aleksandrs Leitis

Low-loss nanostructured dielectric metasurfaces have emerged as a breakthrough platform for ultrathin optics and cutting-edge photonic applications, including beam shaping, focusing, and holography. However, the static nature of their constituent materials ...

2020

Determination of the internal piezoelectric potentials and indium concentration in InGaN based quantum wells grown on relaxed InGaN pseudo-substrates by off-axis electron holography

Victor Carle Adrien Boureau

Micro light emitting diodes have been grown by metal organic vapor phase epitaxy on standard GaN and partly relaxed InGaNOS substrates with the purpose of incorporating higher concentrations of indium for identical growth conditions. Green emission has bee ...

2020

Biaxial flexural fatigue behavior of strain-hardening UHPFRC thin slab elements

Eugen Brühwiler, Xiujiang Shen

The biaxial flexural fatigue behavior of thin slab elements made of strain-hardening Ultra High Performance Fiber Reinforced Cementitious Composite (UHPFRC) is investigated experimentally by means of the ring-on-ring test method. Fourteen flexural fatigue ...

2020

Holographic reconstruction of interlayer distance of bilayer two-dimensional crystal samples from their convergent beam electron diffraction patterns

Tatiana Latychevskaia

Convergent beam electron diffraction (CBED) patterns of twisted bilayer samples exhibit interference patterns in their CBED spots. Such interference patterns can be treated as off-axis holograms and the phase of the scattered waves, and hence the interlaye ...

2020

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

Holographic imaging of electromagnetic fields via electron-light quantum interference

Fabrizio Carbone, Ivan Madan, Giovanni Maria Vanacore, Enrico Pomarico, Gabriele Berruto, Tatiana Latychevskaia, Tom Theodorus Antonius Lummen

Holography relies on the interference between a known reference and a signal of interest to reconstruct both the amplitude and the phase of that signal. With electrons, the extension of holography to the ultrafast time domain remains a challenge, although ...

American Association for the Advancement of Science (AAAS)2019

Convergent and divergent beam electron holography and reconstruction of adsorbates on free-standing two-dimensional crystals

Tatiana Latychevskaia

Van der Waals heterostructures have been lately intensively studied because they offer a large variety of properties that can be controlled by selecting 2D materials and their sequence in the stack. The exact arrangement of the layers as well as the exact ...

HIGHER EDUCATION PRESS2019