Carlo Spezzani
A5011147097- Particle Accelerators and Free-Electron Lasers
- Advanced X-ray Imaging Techniques
- Laser-Matter Interactions and Applications
- Magnetic properties of thin films
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Advanced Electron Microscopy Techniques and Applications
- Gyrotron and Vacuum Electronics Research
- Magnetic Properties and Applications
- Advanced Fiber Laser Technologies
- Advanced Chemical Physics Studies
- Laser Design and Applications
- Atomic and Molecular Physics
- Mass Spectrometry Techniques and Applications
- Theoretical and Computational Physics
- Magnetic and transport properties of perovskites and related materials
- X-ray Spectroscopy and Fluorescence Analysis
- Orbital Angular Momentum in Optics
- ZnO doping and properties
- Crystallography and Radiation Phenomena
- Spectroscopy and Quantum Chemical Studies
- Magnetic Properties of Alloys
- Superconducting Materials and Applications
- Characterization and Applications of Magnetic Nanoparticles
- Multiferroics and related materials
Elettra-Sincrotrone Trieste S.C.p.A.
2016-2025
Vitenparken
2024
Fritz Haber Institute of the Max Planck Society
2022
University of North Georgia
2022
Centre National de la Recherche Scientifique
2015-2020
Laboratoire de physique des Solides
2015-2020
Université Paris-Saclay
2003-2020
Laboratoire Interactions, Dynamiques et Lasers
2020
CEA Paris-Saclay
2020
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2020
Optical vortices are currently one of the most intensively studied topics in optics. These light beams, which carry orbital angular momentum (OAM), have been successfully utilized visible and infrared a wide variety applications. Moving to shorter wavelengths may open up completely new research directions areas optical physics material characterization. Here, we report on generation extreme-ultraviolet with femtosecond duration carrying controllable amount OAM. From basic viewpoint, our...
Exploring the dynamics of matter driven to extreme non-equilibrium states by an intense ultrashort X-ray pulse is becoming reality, thanks advent free-electron laser technology that allows development different schemes for probing response at variable time delay with a second pulse. Here we report generation two-colour ultraviolet pulses controlled wavelengths, intensity and timing seeding high-gain harmonic multiple independent pulses. The potential this new scheme demonstrated evolution...
FERMI is a seeded free-electron laser (FEL) facility located at the Elettra laboratory in Trieste, Italy, and now user operation with its first FEL line, FEL-1, covering wavelength range between 100 20 nm. The second FEL-2, high-gain harmonic generation double-stage cascade 20-4 nm, has also completed commissioning call been recently opened. An overview of typical operating modes presented.
The FERMI facility in Trieste, Italy, is ideal for generating and measuring light characterized by tunable polarization states the vacuum ultraviolet spectral range. New results reveal a high degree of (>0.9) over 26--55 nanometers.
Abstract The recent development of ultrafast extreme ultraviolet (XUV) coherent light sources bears great potential for a better understanding the structure and dynamics matter. Promising routes are advanced control nonlinear spectroscopy schemes in XUV energy range, yielding unprecedented spatial temporal resolution. However, their implementation has been hampered by experimental challenge generating pulse sequences with precisely controlled timing phase properties. In particular, direct...
Advances in developing ultrafast coherent sources operating at extreme ultraviolet (EUV) and x-ray wavelengths allow the extension of nonlinear optical techniques to shorter wavelengths. Here, we describe EUV transient grating spectroscopy, which two crossed femtosecond pulses produce spatially periodic nanoscale excitations sample their dynamics is probed via diffraction a third time-delayed pulse. The use radiation with down 13.3 nm allowed us gratings periods as short 28 observe thermal...
We report on the experimental evidence of magnetic helicoidal dichroism, observed in interaction an extreme ultraviolet vortex beam carrying orbital angular momentum with a vortex. Numerical simulations based classical electromagnetic theory show that this dichroism is interference light modes different momenta, which are populated after between and topology. This observation gives insight into interplay magnetism sets framework for development new analytical tools to investigate ultrafast...
FERMI@Elettra is a free electron-laser (FEL)-based user facility that, after two years of commissioning, started preliminary users' dedicated runs in 2011. At variance with other FEL facilities, has been designed to deliver improved spectral stability and longitudinal coherence. The adopted scheme, which uses an external laser initiate the process, demonstrated be capable generating pulses close Fourier transform limit. We report on first instance wavelength tuning, both narrow large range...
Abstract The advent of free-electron laser (FEL) sources delivering two synchronized pulses different wavelengths (or colours) has made available a whole range novel pump–probe experiments. This communication describes major step forward using new configuration the FERMI FEL-seeded source to deliver with wavelengths, each tunable independently over broad spectral adjustable time delay. FEL scheme makes use seed beams and split radiator section generate extreme ultraviolet from distinct...
FERMI is the first user facility based upon an externally seeded free-electron laser (FEL) and was designed to deliver high quality, transversely longitudinally coherent radiation pulses in extreme ultraviolet soft x-ray spectral regimes. The linear accelerator includes a heater control longitudinal microbunching instability, which otherwise expected degrade quality of brightness electron beam sufficiently reduce FEL output intensity brightness. In this paper, we present results...
We demonstrate the generation of extreme-ultraviolet (XUV) free-electron laser (FEL) pulses with time-dependent polarization. To achieve polarization modulation on a femtosecond timescale, we combine two mutually delayed counterrotating circularly polarized subpulses from cross-polarized undulators. The profile is probed by angle-resolved photoemission and above-threshold ionization helium; results agree solutions Schrödinger equation. stability limit scheme mainly set electron-beam energy...
We have determined the effective attenuation length of photoelectrons over range kinetic energies from 4 to 6 keV in Co, Cu, Ge, and ${\mathrm{Gd}}_{2}{\mathrm{O}}_{3}$. The intensity substrate (Si) overlayer core level peaks was measured as a function thickness wedge-shaped overlayers. Experimental values vary between 45--50 \AA{} at 60--65 Ge. Smaller (30 50 \AA{}, respectively) are found Our results confirm that, for different classes materials, high energy photoemission spectroscopy has...
We demonstrate for the first time that seeded harmonic generation on electron storage rings can produce coherent optical pulses in vacuum ultraviolet spectral range. The experiment is performed at Elettra, where are generated 132 nm, with a duration of about 100 fs. light source has repetition rate 1 kHz and adjustable polarization; it very bright, peak power several orders magnitude above spontaneous synchrotron radiation. Owing to high stability, used test photoemission microscopy...
Abstract Polarization control is a key feature of light generated by short-wavelength free-electron lasers. In this work, we report the first experimental characterization polarization properties an extreme ultraviolet high gain laser operated with crossed polarized undulators. We investigate average degree and shot-to-shot stability analyze aspects such as existing possibilities for controlling switching state emitted light. The results are in agreement predictions based on Gaussian beams...
We present the experimental demonstration of a method for generating two spectrally and temporally separated pulses by an externally seeded, single-pass free-electron laser operating in extreme-ultraviolet spectral range. Our results, collected on FERMI@Elettra facility confirmed numerical simulations, demonstrate possibility controlling both temporal features generated pulses. A operated this mode becomes suitable light source jitter-free, two-colour pump-probe experiments.
We present the main features of CITIUS, a new light source for ultrafast science, generating tunable, intense, femtosecond pulses in spectral range from IR to XUV. The XUV (about 10^5-10^8 photons/pulse 14-80 eV) are produced by laser-induced high-order harmonic generation gas. This radiation is monochromatized time-preserving monochromator, allowing also work with high-resolution bandwidth selection. tunable IR-UV (10^{12}-10^{15} 0.4-5.6 generated an optical parametric amplifier, which...
Quantum mechanically, photoionization can be fully described by the complex amplitudes that describe transition between ground state and continuum state. Knowledge of value phase these has been a central interest in studies newly developing attosecond science, since reveal important information about phenomena such as electron correlation. We present new attosecond-precision interferometric method angle-resolved measurement for amplitudes, using two phase-locked Extreme Ultraviolet pulses...
The FERMI@Elettra project is a seeded free electron laser (FEL) source, based on the High Gain Harmonic Generation (HGHG) scheme. It designed to supply photons in spectral range from 65 20 nm with first undulator line (FEL-1) and 4 second (FEL-2). After period of commissioning beam up 100 MeV at low charge, started August 2009, several phases installations periods have been alternated through 2010. On December 2010 FEL light FEL-1 was obtained 43 by adopting as an initial seed third harmonic...
We use element-resolved IR-pump/extreme ultraviolet-probe experiments to disentangle the ultrafast interplay of magnetic sublattices an ordered crystalline alloy. As a paradigmatic example, we investigate case FeRh alloy, which shows delayed response for different components. Furthermore, detailed time-resolved magneto-optic study that data can be analyzed by only assuming Elliot-Yafet-like scattering, as underlying mechanism demagnetization, resulting in unexpected nonmonotonic dependence...