A5031938201- Laser-Matter Interactions and Applications
- Advanced X-ray Imaging Techniques
- Mass Spectrometry Techniques and Applications
- Laser-induced spectroscopy and plasma
- Laser-Plasma Interactions and Diagnostics
- Advanced Chemical Physics Studies
- Advanced Fiber Laser Technologies
- Spectroscopy and Quantum Chemical Studies
- Optical Coherence Tomography Applications
- Ion-surface interactions and analysis
- Spectroscopy and Laser Applications
- Advanced Electron Microscopy Techniques and Applications
- Advanced Fluorescence Microscopy Techniques
- Quantum, superfluid, helium dynamics
- High-pressure geophysics and materials
- Atomic and Molecular Physics
- Terahertz technology and applications
- Photoacoustic and Ultrasonic Imaging
- Spectroscopy Techniques in Biomedical and Chemical Research
- Integrated Circuits and Semiconductor Failure Analysis
- Near-Field Optical Microscopy
- Electron and X-Ray Spectroscopy Techniques
- Magneto-Optical Properties and Applications
- Random lasers and scattering media
- Particle Accelerators and Free-Electron Lasers
Deutsches Elektronen-Synchrotron DESY
2020-2024
Friedrich Schiller University Jena
2018-2022
Helmholtz Institute Jena
2018-2022
Helmut Schmidt University
2022
University of New York in Prague
2022
Charles University
2022
Imperial College London
2022
European X-Ray Free-Electron Laser
2022
Universität Hamburg
2022
GSI Helmholtz Centre for Heavy Ion Research
2022
We report on the dynamics of ultrafast heating in cryogenic hydrogen initiated by a ≲300 fs, 92 eV free electron laser x-ray burst. The rise scattering amplitude from second pulse probes transition dense molecular to nearly uncorrelated plasmalike structure, indicating an electron-ion equilibration time ∼0.9 ps. agrees with radiation hydrodynamics simulations based conductivity model for partially ionized plasma that is validated two-temperature density-functional theory.
The presence of a weak second-harmonic field in an intense-laser ionization experiment affects the momentum-resolved electron yield, depending on relative phase between ω and 2ω component. proposed two-color "phase-of-the-phase spectroscopy" quantifies for each final momentum relative-phase contrast (RPC) (PP) describing how much with which lag, respectively, yield changes as function phase. Experimental results RPC PP spectra rare gas atoms CO_{2} are presented. demonstrate rather universal...
Strong laser fields can be used to trigger an ultrafast molecular response that involves electronic excitation and ionization dynamics. Here, we report on the experimental control of spatial localization in C_{60} fullerene exerted by intense few-cycle (4 fs) pulse at 720 nm. The is achieved tailoring carrier-envelope phase polarization pulse. We find maxima minima photoemission-asymmetry parameter along laser-polarization axis are synchronized with coherent wave packet around time ionization.
Abstract In the strong-field photoemission from atoms, molecules, and surfaces, fastest electrons emerge tunneling subsequent field-driven recollision, followed by elastic backscattering. This rescattering picture is central to attosecond science enables control of electron’s trajectory via sub-cycle evolution laser electric field. Here we reveal a so far unexplored route for waveform-controlled electron acceleration emerging forward in resonant plasmonic systems. We studied plasmon-enhanced...
High-harmonic generation (HHG) in crystals offers a simple, affordable and easily accessible route to carrier-envelope phase (CEP) measurements, which scales favorably towards longer wavelengths. We present measurements of HHG ZnO using few-cycle pulses at 3.1µm. Thanks the broad bandwidth driving laser pulses, spectral overlap between adjacent harmonic orders is achieved. The resulting interference pattern provides access relative phase, hence, CEP.
Above-threshold ionization spectra from cesium are measured as a function of the carrier-envelope phase (CEP) using laser pulses centered at $3.1\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ wavelength. The directional asymmetry in energy backscattered electrons oscillates three times, rather than once, CEP is changed 0 to $2\ensuremath{\pi}$. Using improved strong-field approximation, we show that unusual behavior arises interference few quantum orbits. We discuss conditions for observing...
We investigate subpicosecond dynamics of warm dense hydrogen at the XUV free-electron laser facility (FLASH) DESY (Hamburg). Ultrafast impulsive electron heating is initiated by a ≤300-fs short x-ray burst 92-eV photon energy. A second pulse probes sample via scattering jitter-free variable time delay. show that initial molecular structure dissociates within (0.9±0.2) ps, allowing us to infer energy transfer rate between electrons and ions. evaluate Saha Thomas-Fermi ionization models in...
Scientific and technological progress depend substantially on the ability to image nanoscale. In order investigate complex, functional, nanoscopic structures like, e.g., semiconductor devices, multilayer optics, or stacks of 2D materials, imaging techniques not only have provide images but should also quantitative information. We report material-specific characterization buried with extreme ultraviolet coherence tomography. The method is demonstrated at a laser-driven broadband radiation...
We present a modular extreme ultraviolet (XUV) spectrometer system optimized for broad spectral range of 12–41 nm (30–99 eV) with high resolution λ/Δλ ≳ 784 ± 89. The has several operation modes (1) XUV beam inspection, (2) angular analysis, and (3) imaging spectroscopy. These options allow versatile use in harmonic spectroscopy analysis. performance the is demonstrated using novel cross-sectional method called coherence tomography.
A key feature of extreme ultraviolet (XUV) radiation from free-electron lasers (FELs) is its spatial and temporal coherence. We measured the spatio-temporal coherence properties monochromatized FEL pulses at 13.5 nm using a Michelson interferometer. time (59±8) fs has been determined, which in good agreement with spectral bandwidth given by monochromator. Moreover, vertical direction amounts to about 15% beam diameter 12% horizontal direction. The feasibility measuring XUV interferometric...
By applying recently introduced, phase-of-the-phase spectroscopy [S. Skruszewicz et al., Phys. Rev. Lett. 115, 043001 (2015)], we analyze the phase-dependent photoelectron signal from Xe ionized in intense, parallel, two-color (1800 nm and 900 nm) laser fields. With such a field configuration, tuning of relative phase between ionizing, $\ensuremath{\omega}$, perturbative, $2\ensuremath{\omega}$, results modulation ionization rate, as well modifications trajectories electrons propagating...
Abstract Wave packet interferometry provides benchmark information on light-induced electronic quantum states by monitoring their relative amplitudes and phases during coherent excitation, propagation, decay. The phase control of soft x-ray pulse replicas the single-digit attosecond timescale achieved in our experiments makes this method a powerful tool to probe ultrafast phenomena such as excitation Auger shake-up with sub-cycle precision. In contribution we present first results obtained...
We show that rotational line spectra of molecular clusters with near zero permanent dipole moments can be observed using impulsive alignment. Aligned wavepackets were generated by non-resonant interaction intense femtosecond laser pump pulses and then probed Coulomb explosion a second, time-delayed pulse. By means Fourier transform rich spectrum eigenstates was derived. For the smallest cluster, C(2)H(2)-He, we able to establish essentially all up dissociation threshold on basis theoretical...
We present a laboratory beamline dedicated to nanoscale subsurface imaging using extreme ultraviolet coherence tomography (XCT). In this setup, broad-bandwidth (XUV) radiation is generated by laser-driven high-harmonic source. The able handle spectral range of 30-130 eV and beam divergence 10 mrad (full width at half maximum). XUV focused on the sample under investigation, broadband reflectivity measured an spectrometer. For given window, XCT particularly suited investigate silicon-based...
Momentum-resolved photoelectron emission from xenon in colinearly polarized two-color laser fields at above-threshold ionization conditions is studied both experimentally and theoretically. We utilize phase-of-the-phase spectroscopy as recently introduced by Skruszewicz et al., Phys. Rev. Lett. 115, 043001 (2015) to analyze the dependence of yields on relative phase $\varphi$ between fundamental second harmonic fields. The resulting phase-of-phase spectra feature a characteristic...
We present an extreme ultraviolet (EUV) microscope using a Schwarzschild objective which is optimized for single-shot sub-micrometer imaging of laser-plasma targets. The has been designed and constructed the scattering from EUV-heated solid-density hydrogen jet. Imaging cryogenic target was demonstrated single pulses free-electron laser in Hamburg (FLASH) at wavelength 13.5 nm. In exposure, we observe jet with ice fragments spatial resolution range. situ EUV expected to enable novel...
Abstract Field localization by nanostructures illuminated with laser pulses of well-defined waveform enables spatio-temporal tailoring the near-fields for sub-cycle control electron dynamics at nanoscale. Here, we apply intense linearly-polarized two-color all-optical highest energy emission from SiO 2 nanoparticles. For size regime where light propagation effects become important, demonstrate possibility to preferential angle a considerable fraction fastest electrons varying relative phase...
The electrical conductivity of water under extreme temperatures and densities plays a central role in modeling planetary magnetic fields. Experimental data are vital to test theories high-energy-density assess the possible development presence extraterrestrial life. These states also important biology chemistry studies when specimens confined excited using ultrafast optical or free-electron lasers (FELs). Here we utilize femtosecond measure transient reflection transmission ultrathin sheet...
A high-precision, single-shot, and real-time carrier-envelope phase (CEP) measurement at 1.8 μm laser wavelength based on stereographic photoelectron spectroscopy is presented. precision of the CEP 120 mrad for each every individual shot a 1 kHz pulse train with randomly varying demonstrated. Simultaneous to measurement, lengths are characterized by evaluating spatial asymmetry measured above-threshold ionization (ATI) spectra xenon referenced standard pulse-duration frequency-resolved...
Dense cryogenic hydrogen is heated by intense femtosecond infrared laser pulses at intensities of 1015-1016 Wcm-2. Three-dimensional particle-in-cell (PIC) simulations predict that this heating limited to the skin depth, causing an inhomogeneously outer shell with a cold core and two prominent temperatures about 25 40 eV for simulated delay times up +70 fs after pulse maximum. Experimentally, time-integrated emitted bremsstrahlung in spectral range 8-18 nm was corrected wavelength-dependent...
We report on the simultaneous determination of non-linear dispersion functions and resolving power three flat-field XUV grating spectrometers. A moderate-intense short-pulse infrared laser is focused onto technical aluminum which commonly present as part experimental setup. In wavelength range 10–19 nm, spectrometers are calibrated using Al-Mg plasma emission lines. This cross-calibration performed in-situ in very same setup actual main experiment. The results excellent agreement with...
We have developed an easy-to-use and reliable timing tool to determine the arrival time of optical laser a free electron (FEL) pulses within jitter limitation. This can be used from XUV X-rays exploits high FELs intensities. It uses shadowgraph technique where we optically (at 800 nm) image plasma created by intense or X-ray FEL pulse on transparent sample (glass slide) directly placed at pump - probe position. is based physical principle that properties material are drastically changed when...
Abstract We present an overview of recent results on optical coherence tomography with the use extreme ultraviolet and soft X-ray radiation (XCT). XCT is a cross-sectional imaging method that has emerged as derivative (OCT). In contrast to OCT, which typically uses near-infrared light, utilizes broad bandwidth (XUV) (SXR) (Fuchs et al in Sci Rep 6:20658, 2016). As XCT’s axial resolution only scales length light source. Thus, down nanometer range can be achieved. This improvement up three...