Publications associées à Towards X-ray transient grating 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

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

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

Interfacial engineering through lead binding using crown ethers in perovskite solar cells

Jun Ho Yum, Kevin Sivula, Jiyoun Seo, Jovana Milic, Yeonju Kim

In the domain of perovskite solar cells (PSCs), the imperative to reconcile impressive photovoltaic performance with lead-related issue and environmental stability has driven innovative solutions. This study pioneers an approach that not only rectifies lea ...

Elsevier2024

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

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

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

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

Gamma-ray Spectroscopy in Low-Power Nuclear Research Reactors

Andreas Pautz, Oskari Ville Pakari, Vincent Pierre Lamirand

Gamma-ray spectroscopy is an effective technique for radioactive material characterization, routine inventory verification, nuclear safeguards, health physics, and source search scenarios. Gamma-ray spectrometers typically cannot be operated in the immedia ...

MDPI2024

Subsurface fluorescence time-of-flight imaging using a large-format single-photon avalanche diode sensor for tumor depth assessment

Claudio Bruschini, Edoardo Charbon, Arin Can Ülkü, Yichen Feng

Significance: Fluorescence guidance is used clinically by surgeons to visualize anatomical and/or physiological phenomena in the surgical field that are difficult or impossible to detect by the naked eye. Such phenomena include tissue perfusion or molecula ...

SPIE Society of Photo-optical Instrumentation Engineers2024

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

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

Element- and enantiomer-selective visualization of molecular motion in real-time

Majed Chergui, Malte Oppermann, Jérémy Raymond Jean Maurice Rouxel

Ultrafast optical-domain spectroscopies allow to monitor in real time the motion of nuclei in molecules. Achieving element-selectivity had to await the advent of time resolved X-ray spectroscopy, which is now commonly carried at X-ray free electron lasers. ...

Nature Portfolio2023

Jahn-Teller effects in initial and final states: high-resolution X-ray absorption, photoelectron and Auger spectroscopy of allene

Majed Chergui, Luca Longetti, Thomas Roland Barillot, Camila Bacellar Cases Da Silveira, Rebecca Ann Ingle, Daniel Hollas, Ludmila Maria Diniz Leroy

Carbon K-edge resonant Auger spectra of gas-phase allene following excitation of the pre-edge 1s -> pi* transitions are presented and analysed with the support of EOM-CCSD/cc-pVTZ calculations. X-Ray absorption (XAS), X-ray photoelectron (XPS), valence ban ...

ROYAL SOC CHEMISTRY2023

Electrical spectroscopy of defect states and their hybridization in monolayer MoS2

Andras Kis, Oleg Yazyev, Yanfei Zhao, Juan Francisco Gonzalez Marin, Ahmet Avsar, Cheol Yeon Cheon, Kristians Cernevics, Zhenyu Wang, Mukesh Kumar Tripathi, Hyungoo Ji

Defects in solids are unavoidable and can create complex electronic states that can significantly influence the electrical and optical properties of semiconductors. With the rapid progress in the integration of 2D semiconductors in practical devices, it is ...

Nature Research2023

Cost-effective equalization of electro-optic frequency combs in a Sagnac interferometer

Camille Sophie Brès, Jianqi Hu, Ivan Cardea

We present a cost-effective electro-optic frequency comb generation and equalization method using a single phase modulator inserted in a Sagnac interferometer layout. The equalization relies on the interference of comb lines generated in both clockwise and ...

Optica Publishing Group2023

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

Hydrogenated amorphous silicon high flux x-ray detectors for synchrotron microbeam radiation therapy

Sylvain Dunand, Nicolas Würsch, Giulia Rossi, Matthew James Large

Objective. Microbeam radiation therapy (MRT) is an alternative emerging radiotherapy treatment modality which has demonstrated effective radioresistant tumour control while sparing surrounding healthy tissue in preclinical trials. This apparent selectivity ...

IOP Publishing Ltd2023

Fluorescence crosstalk reduction by modulated excitation-synchronous acquisition for multispectral analysis in high-throughput droplet microfluidics

Christoph Merten, Jatin Panwar

Crosstalk between fluorescent biomarkers significantly limits the resolution of multispectral fluorescence analysis in real-time droplet-microfluidics applications. The crosstalk is a result of overlapping emission and excitation spectra of different fluor ...

ROYAL SOC CHEMISTRY2023