Publications associées à Femtosecond pulse length and arrival time measurement of hard X-Ray FELs

Numerical Study of the Attosecond Free-Electron Laser Pulse Generation in the Soft X-ray Regime at the SwissFEL

Isolated attosecond pulses from an X-ray free-electron laser are in high demand for attosecond science, which enables the probing of electron dynamics by X-ray nonlinear spectroscopy and single-particle imaging. The aim of this thesis is to simulate attos ...

EPFL2024

Influence of ionization and cumulative effects on laser-induced crystallization in multilayer dielectrics

Yves Bellouard, Ruben Ricca, Victor Carle Adrien Boureau

Crystallization of amorphous layers has been demonstrated under various radically different laser-exposure conditions, including continuous wave (cw) and pulsed lasers. Here, we investigate the specific role of ionization in the crystallization of dielectr ...

2024

Femtosecond-laser direct-write photoconductive patterns on tellurite glass

Yves Bellouard, Gözden Torun, Anastasia Romashkina

We report the formation of arbitrary photoconductive patterns made of tellurium (Te) nanocrystals by exposing a tellurite (TeO2-based) glass to femtosecond laser pulses. During this process, Te/TeO2-glass nanocomposite interfaces with photoconductive prope ...

American Physical Society (APS)2024

Exciton migration in two-dimensional materials

Excitons play an essential role in the optical response of two-dimensional materials. These are bound states showing up in the band gaps of many-body systems and are conceived as quasiparticles formed by an electron and a hole. By performing real-time simu ...

Nature Portfolio2024

Direct observations of X-rays produced by upward positive lightning

Farhad Rachidi-Haeri, Marcos Rubinstein, Antonio Sunjerga, Thomas Chaumont

X-rays have been observed in natural downward cloud-to-ground lightning for over 20 years and in rocket-triggered lightning for slightly less. In both cases, this energetic radiation has been detected during the stepped and dart leader phases of downward n ...

Nature Publishing Group2024

A compact approach to higher-resolution resonant inelastic x-ray scattering detection using photoelectrons

Henrik Moodysson Rønnow, Markus Scholz

The detection of inelastically scattered soft x-rays with high energy resolution usually requires large grating spectrometers. Recently, photoelectron spectrometry for analysis of x-rays (PAX) has been rediscovered for modern spectroscopy experiments at sy ...

Iop Publishing Ltd2024

Investigating Non-equilibrium Physics in Wide Bandgap Semiconductors and Quantum Materials via Ultrafast Spectroscopy

Hui-Yuan Chen

This thesis uses femtosecond laser spectroscopy in studying strong correlation in condensed matters that are pertinent to future technology: a wide bandgap perovskite and a quantum material, with the employment of ultrafast time-resolved spectroscopy in th ...

EPFL2024

Room-Temperature Quantum Optomechanics and Free-Electron Quantum Optics

Guanhao Huang

Quantum optics studies how photons interact with other forms of matter, the understanding of which was crucial for the development of quantum mechanics as a whole. Starting from the photoelectric effect, the quantum property of light has led to the develop ...

EPFL2024

Terahertz emission from diamond nitrogen-vacancy centers

László Forró, Ferenc Simon, Sándor Kollarics, Bence Gábor Márkus

Coherent light sources emitting in the terahertz range are highly sought after for fundamental research and applications. Terahertz lasers rely on achieving population inversion. We demonstrate the generation of terahertz radiation using nitrogen-vacancy c ...

Amer Assoc Advancement Science2024

Investigation of room-temperature single-photon emitters in GaN-based materials and GaN/AlN quantum dots

Johann Nicolaï Stachurski

Over the past decade, quantum photonics platforms aiming at harnessing the fundamental properties of single particles, such as quantum superposition and quantum entanglement, have flourished. In this context, single-photon emitters capable of operating at ...

EPFL2024

Laser-based manufacturing of freeform glass micro-optics through topological transformation

Samuel Youcef Benketaf

Glass has been the material of choice for making optical elements, in large part due to its intrinsic properties: a temperature-dependent viscosity, which enables shaping the material into a broad variety of functional and artistic glassware. Silica glass ...

EPFL2024

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

Photothermal spectroscopy on-chip sensor for the measurement of a PMMA film using a silicon nitride micro-ring resonator and an external cavity quantum cascade laser

Simone Iadanza

Laser-based mid-infrared (mid-IR) photothermal spectroscopy (PTS) represents a selective, fast, and sensitive analytical technique. Recent developments in laser design permits the coverage of wider spectral regions in combination with higher power, enablin ...

Walter De Gruyter Gmbh2024

Shaped Laser Pulses for Microsecond Time-Resolved Cryo-EM: Outrunning Crystallization during Flash Melting

Marcel Drabbels, Ulrich Lorenz, Constantin Richard Krüger, Nathan Junior Mowry

Water vitrifies if cooled at rates above 3 × 105 K/s. In contrast, when the resulting amorphous ice is flash heated, crystallization occurs even at a more than 10 times higher heating rate, as we have recently shown. This may present an issue for microseco ...

2024

Energy-Efficient Particle Accelerators for Research

Mike Seidel

Particle accelerators are the drivers for large-scale research infrastructures for particle physics but also for many branches of condensed matter research. The types of accelerator-driven research infrastructures include particle colliders, neutron, muon ...

2024

Progress and prospects in nonlinear extreme-ultraviolet and X-ray optics and spectroscopy

Majed Chergui

Free-electron lasers and high-harmonic-generation table-top systems are new sources of extreme-ultraviolet to hard X-ray photons, providing ultrashort pulses that are intense, coherent and tunable. They are enabling a broad range of nonlinear optical and s ...

NATURE PORTFOLIO2023

On the interaction of femtosecond laser pulses with layered dielectric materials

Ruben Ricca

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

Generation and control of localized terahertz fields in photoemitted electron plasmas

Fabrizio Carbone, Ivan Madan, Giovanni Maria Vanacore, Francesco Barantani, Ido Kaminer, Simone Gargiulo

Dense micron-sized electron plasmas, such as those generated upon irradiation of nanostructured metallic surfaces by intense femtosecond laser pulses, constitute a rich playground to study light-matter interactions, many-body phenomena, and out-of-equilibr ...

ROYAL SOC CHEMISTRY2023

Down-conversion of a single photon as a probe of many-body localization

Cristiano Ciuti

Decay of a particle into more particles is a ubiquitous phenomenon to interacting quantum systems, taking place in colliders, nuclear reactors or solids. In a nonlinear medium, even a single photon would decay by down-converting (splitting) into lower-freq ...

NATURE PORTFOLIO2023

Terahertz waveform synthesis in integrated thin-film lithium niobate platform

Jérôme Faist, Ileana-Cristina Benea-Chelmus, Francesca Fabiana Settembrini

Bridging the "terahertz gap" relies upon synthesizing arbitrary waveforms in the terahertz domain enabling applications that require both narrow band sources for sensing and few-cycle drives for classical and quantum objects. However, realization of custom ...

Nature Portfolio2023