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

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

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

Nonlinear optical diode effect in a magnetic Weyl semimetal

Philip Johannes Walter Moll, Chunyu Guo, Hao Yang

Diode effects are of great interest for both fundamental physics and modern technologies. Electrical diode effects (nonreciprocal transport) have been observed in Weyl systems. Optical diode effects arising from the Weyl fermions have been theoretically co ...

Nature Portfolio2024

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

Pressure stabilization effect on the donor-acceptor polyiodide chains in tetraethylammonium bis(diiodine) triiodide - insights from Raman spectroscopy

Nicola Casati, Tomasz Poreba

Polyiodides present high bonding flexibility already at ambient conditions, and undergo significant pressure-induced structural deformations. Resonant Raman spectroscopy has been widely used to study I-I bonds in various polyiodides, but it carries a risk ...

Royal Soc Chemistry2024

Parametric Wavelength Conversion in Waveguiding Structures: Efficiency, Bandwidth and Polarization

Arman Ayan

Photonics integrated circuits are a promising solution for the growing demands of data transmission and future system-on-chip technologies. Within this context, nonlinear optical interactions offer unique opportunities for all-optical processing, sampling, ...

EPFL2024

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

Optimizing Dynamic Aperture Studies with Active Learning

Tatiana Pieloni, Massimo Giovannozzi, Ekaterina Krymova, Mike Seidel, Davide Di Croce

Dynamic aperture is an important concept for the study of non-linear beam dynamics in circular accelerators. It describes the extent of the phase-space region where a particle's motion remains bounded over a given number of turns. Understanding the feature ...

Iop Publishing Ltd2024

Controlling crystal cleavage in focused ion beam shaped specimens for surface spectroscopy

Philip Johannes Walter Moll, Matthias Carsten Putzke, Andrew Scott Hunter

Our understanding of quantum materials is commonly based on precise determinations of their electronic spectrum by spectroscopic means, most notably angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy. Both require atomicall ...

Aip Publishing2024

Light Emission and Conductance Fluctuations in Electrically Driven and Plasmonically Enhanced Molecular Junctions

Christophe Marcel Georges Galland, Sakthi Priya Amirtharaj, Wen Chen, Konstantin Malchow

Electrically connected and plasmonically enhanced molecular junctions combine the optical functionalities of high field confinement and enhancement (cavity function), and of high radiative efficiency (antenna function) with the electrical functionalities o ...

Amer Chemical Soc2024

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

Electric-field-induced second-order nonlinear processes in stoichiometric silicon nitride

Boris Zabelich

Nonlinear optical frequency conversion is one of the driving research areas in photonics. Its quasi instantaneous response and the promise of low power consumption in integrated structures could cover the demand for fast signal processing with minimal ener ...

EPFL2024

Advanced Silicon and SWIR Single-Photon Avalanche Diodes: Design, Simulation, and Characterization

Ekin Kizilkan

Low-level light detection with high spatial and timing accuracy is a growing area of interest by virtue of applications such as light detection and ranging (LiDAR), biomedical imaging, time-resolved Raman spectroscopy, and quantum applications. Single-phot ...

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

Resonant Tip-Enhanced Raman Spectroscopy of a Single-Molecule Kondo System

Jiri Dolezal

Tip-enhanced Raman spectroscopy (TERS) under ultrahigh vacuum and cryogenic conditions enables exploration of the relations between the adsorption geometry, electronic state, and vibrational fingerprints of individual molecules. TERS capability of reflecti ...

Amer Chemical Soc2024

Impact of microwave beam scattering by density fluctuations on the electron-cyclotron power deposition profile in tokamaks

Stefano Coda, Joan Decker, Jean Arthur Cazabonne, Umesh Kumar, Oleg Krutkin

Electron-cyclotron waves are a tool commonly used in tokamaks, in particular to drive current. Their ability to drive current in a very localized manner renders them an optimal tool for MHD mode mitigation. However, such applications require high accuracy ...

IOP Publishing Ltd2024

X-ray chemical imaging for assessing redox microsites within soils and sediments

Vincent Noel, Meret Aeppli

Redox reactions underlie several biogeochemical processes and are typically spatiotemporally heterogeneous in soils and sediments. However, redox heterogeneity has yet to be incorporated into mainstream conceptualizations and modeling of soil biogeochemist ...

Frontiers Media Sa2024

Experimental demonstration of attosecond pump-probe spectroscopy with an X-ray free-electron laser

Jun Wang, Christoph Bostedt, Siqi Li, Zhen Zhang, Zhaoheng Guo, Xiang Li

Pump-probe experiments with subfemtosecond resolution are the key to understanding electronic dynamics in quantum systems. Here we demonstrate the generation and control of subfemtosecond pulse pairs from a two-colour X-ray free-electron laser. By measurin ...

Nature Publishing Group2024

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