A5082664872- Laser-Matter Interactions and Applications
- Advanced X-ray Imaging Techniques
- Laser-Plasma Interactions and Diagnostics
- Particle Accelerators and Free-Electron Lasers
- Mass Spectrometry Techniques and Applications
- Advanced Electron Microscopy Techniques and Applications
- Atomic and Molecular Physics
- Advanced Chemical Physics Studies
- Advanced Fiber Laser Technologies
- Laser-induced spectroscopy and plasma
- X-ray Spectroscopy and Fluorescence Analysis
- Magnetic properties of thin films
- Nuclear Physics and Applications
- Advancements in Photolithography Techniques
- Laser Design and Applications
- Terahertz technology and applications
- Particle accelerators and beam dynamics
- Electron and X-Ray Spectroscopy Techniques
- Spectroscopy and Laser Applications
- Spectroscopy and Quantum Chemical Studies
- Random lasers and scattering media
- Neural Networks and Reservoir Computing
- Advanced MRI Techniques and Applications
- Agriculture, Soil, Plant Science
- Machine Learning in Materials Science
Universität Hamburg
2014-2024
Hamburg Institut (Germany)
2024
Center for Free-Electron Laser Science
2012-2022
Deutsches Elektronen-Synchrotron DESY
2016-2022
Max Planck Institute for the Structure and Dynamics of Matter
2013-2022
Hamburg Centre for Ultrafast Imaging
2013-2019
Koblenz University of Applied Sciences
2001-2016
Mapper Lithography (Netherlands)
2007-2009
University of Göttingen
2000-2001
Photoelectrons excited by extreme ultraviolet or x-ray photons in the presence of a strong laser field generally suffer spread their energies due to absorption and emission photons. We demonstrate that if emitted electron wave packet is temporally confined small fraction oscillation period interacting light wave, its energy spectrum can be up- downshifted many times photon without substantial broadening. The accelerate decelerate electron's drift velocity, i.e., steer like classical...
Abstract We use intense femtosecond extreme ultraviolet (XUV) pulses with a photon energy of 92 eV from the FLASH free electron laser to irradiate substrate-free CsCl nanoparticles surrounded by He gas number density around 10 15 cm −3 . By simultaneously detecting electrons and energetic ions laser-irradiated micron-size target we study acceleration mechanism light at microplasma-vacuum boundary as well layer close nanoparticle surface. When XUV pulse interacts alone, helium are accelerated...
Initiating the gain process in a free-electron laser (FEL) from an external highly coherent source of radiation is promising way to improve pulse properties such as temporal coherence and synchronization performance time-resolved pump-probe experiments at FEL facilities, but this so-called "seeding" suffers lack adequate sources short wavelengths. We report on first successful seeding wavelength 38.2 nm, resulting GW-level, pulses well significant second harmonic emission 19.1 nm. The seed...
Arrival time fluctuations of extreme-ultraviolet (EUV) pulses from the free-electron laser in Hamburg (FLASH) are measured single-pulse resolved at experimental end-station. To this end, they non-collinearly superimposed space and with visible femtosecond on a GaAs substrate. The EUV irradiation induces changes reflectivity for pulse. temporal delay between two light is directly encoded spatial position change which captured CCD camera. For each single shot, relative EUV/visible arrival-time...
One of the most challenging tasks for extreme ultraviolet, soft and hard x-ray free-electron laser photon diagnostics is precise determination pulse duration, which typically in sub 100 fs range. Nine different methods, able to determine such ultrashort durations, were compared experimentally at FLASH, self-amplified spontaneous emission DESY Hamburg, order identify advantages disadvantages methods. Radiation pulses a wavelength 13.5 24.0 nm together with corresponding electron bunch...
Atomic inner-shell relaxation dynamics were measured at the free-electron laser in Hamburg, FLASH, delivering 92 eV pulses. The decay of 4d core holes created xenon was followed by detection ion charge states after illumination with delayed 400 nm A timing jitter order several hundred femtoseconds between laser- and accelerator-pulses compensated for a simultaneous delay measurement single-shot x-ray/laser cross-correlator. After sorting tagged spectra according to delays, temporal...
Auger decay carries valuable information about the electronic structure and dynamics of atoms, molecules, solids. Here we furnish evidence that under certain conditions electrons are subject to an energetic chirp. The effect is disclosed in time-resolved streaking experiments on Xe NOO Kr MNN using extreme-ultraviolet pulses from free-electron laser Hamburg as well a high-order harmonic source. origin this found be exchange energy between electron earlier emitted correlated photoelectron....
We report on transferring the concept of light-field streaking with intense terahertz fields from free-electron lasers to laboratory scale. Utilizing a commercial laser system, synchronized 300 μm and 13 nm extreme ultraviolet pulses are generated by optical rectification high harmonic generation, respectively. The sufficiently strong support electron wave packet sampling few fs resolution. capability this approach is demonstrated measuring duration formed direct photoemission neon gas target.
Abstract The analysis of isolated spin-wave packets is crucial for the understanding magnetic transport phenomena and particularly interesting applications in spintronic magnonic devices, where implement an information processing scheme with negligible residual heat loss. We have captured microscale magnetization dynamics single metallic ferromagnets space time. Using optically driven high-current picosecond pulse source combination time-resolved scanning Kerr microscopy probed by...
Photofragmentation dynamics of molecular iodine was studied as a response to the joint illumination with femtosecond 800 nm near-infrared and 13 extreme ultraviolet (XUV) pulses delivered by free-electron laser facility FLASH. The interaction target two light different wavelengths but comparable pulse energy elucidates complex intertwined electronic nuclear dynamics. To follow distinct pathways out multitude reaction channels, recoil created ionic fragments is analyzed. delayed XUV provides...
We present first time-resolved measurements of a new mobile full-field transmission microscope [1] obtained at the soft X-ray beamline P04 high brilliance synchrotron radiation source PETRA III.
Irradiation of nanoscale clusters and large molecules with intense laser pulses transforms them into highly-excited non- equilibrium states. The dynamics laser-cluster interaction is encoded in electron kinetic energy spectra, which contain signatures direct photoelectron emission as well thermalized nanoplasma electrons. In this work we report on a so far not observed spectrally narrow bound state signature the spectra from mixed Xe core - Ar shell ionized by extreme-ultraviolet (XUV)...
We report on experiments using high-harmonic (HH) radiation for microscopy imaging at 13 nm wavelength. A simple setup a zone plate as objective and back-illuminated CCD detector yields moderate magnifications of M≈60 spatial resolution δx<0.8 μm demonstrated with sample mica. The HH was monochromatized by means high-efficiency multilayer monochromator consisting two Mo/Si-mirros.
Ultrafast dynamics of a molecular wave packet created by strong 120-fs near-infrared (800 nm) laser pulse in iodine has been probed synchronized 13.4-nm, 35-fs extreme-ultraviolet pulses delivered the free-electron facility Hamburg, FLASH. The kinetic energy release multiply charged ionic fragments reveals three essential steps strong-field-induced fragmentation dynamics: (i) creation I${}_{2}$${}^{2+}$ and (I${}_{2}$${}^{2+}$)${}^{*}$ ions proceeds within (75 $\ifmmode\pm\else\textpm\fi{}$...
We demonstrate second-order interferometric autocorrelation of a pulse in the vacuum-ultraviolet (VUV) spectral range using an optical arrangement equivalent to Michelson interferometer. In all-reflective design, wavefront splitting is realized with two moveable interdigitated reflective gratings forming diffraction pattern well separated orders and intensity distribution depending on precisely adjustable path-length difference. An imaging time-of-flight spectrometer able spatially select...
Extreme ultraviolet (EUV) emission in the 11–15 nm wavelength range from a thin liquid water jet target under illumination with high repetition rate, average power laser (Nd-YLF) has been studied. To find optimum conversion efficiency of light into EUV radiation, different parameters were applied. The intensity was varied between 1011 and 1015 W/cm2, pulse duration 30 ps to 3 ns. A maximum 0.12% 2.2% bandwidth 4π steradian at 13 achieved repetion rate 250 kHz, strong dependence on both found.
The authors introduce a method for cross correlating vacuum-ultraviolet with near-infrared femtosecond light pulses in perpendicular geometry. Photoelectrons generated an atomic gas by laser-assisted photoionization are used to create two-dimensional image of the cross-correlation volume, thereby mapping time onto space coordinate. Thus, information about pulse duration and relative timing between can be obtained without need scan optical delay line. First tests using from free-electron...
Significantly structured and fluctuating temporal profiles of pulses from self-amplified spontaneous emission free electron lasers as well their unstable timing require time diagnostics on a single-shot basis. The duration structure extreme-ultraviolet (XUV) the Free Electron Laser (FEL) in Hamburg (FLASH) are becoming accessible using variation streak camera principle, where photoemitted electrons energetically streaked electric field component terahertz electromagnetic wave. with respect...
The authors have built an X-ray microscope capable of taking snapshots the domain formation process with a high spatial resolution down to few ten nanometers. By exposing sample intense magnetic field pulses, they destroy stable pattern and probe rapid time-evolution magnetization stroboscopically soft flashes created by storage ring PETRA III at DESY in Hamburg. These enable resolving very fast changes configuration occurring hundred picoseconds thus video destruction relaxation dynamics...
We report on a direct time-domain measurement of the temporal properties seeded free-electron laser pulse in extreme ultraviolet spectral range. Utilizing oscillating electromagnetic field terahertz radiation, single-shot THz streak-camera was applied for measuring duration as well phase generated intense XUV pulses. The experiment conducted at FLASH, free electron user facility DESY Hamburg, Germany. In contrast to indirect methods, this approach directly resolves and visualizes frequency...
We demonstrate the generation of microjoule level, sub-20-fs, Ti:Sa fifth-harmonic pulses utilizing a loose-focusing geometry in long Ar gas cell. The VUV centered at 161.8 nm reach pulse energies 1.1 μJ per pulse, while corresponding duration is measured with second-order, fringe-resolved autocorrelation scheme to be 18±1 fs. Nonresonant, two-photon ionization Kr and three-photon Ne verify high-intensity content indicate feasibility multi-photon pump-VUV probe studies ultrafast atomic...
Time-resolved spectroscopy in the vacuum/extreme ultraviolet (VUV/XUV) spectral range promises to disclose ultrafast dynamics all states of matter. Completing a measurement within single shot eliminates influence experimental parameter fluctuations and enhances its statistical significance. We demonstrate single-shot temporal metrology scheme operating vacuum/extreme-ultraviolet range, combining few-femtosecond resolution wide window with high detection efficiency. An anticollinear geometry...