A5076598537- Laser-Matter Interactions and Applications
- Solid State Laser Technologies
- Advanced Fiber Laser Technologies
- Laser-Plasma Interactions and Diagnostics
- Advanced X-ray Imaging Techniques
- Advanced NMR Techniques and Applications
- Mass Spectrometry Techniques and Applications
- Solid-state spectroscopy and crystallography
- Electron Spin Resonance Studies
- Laser Design and Applications
- Particle Accelerators and Free-Electron Lasers
- Terahertz technology and applications
- Advanced Electron Microscopy Techniques and Applications
- Spectroscopy and Quantum Chemical Studies
- Spectroscopy and Laser Applications
- Diamond and Carbon-based Materials Research
- Ion-surface interactions and analysis
- Advanced Chemical Physics Studies
- Integrated Circuits and Semiconductor Failure Analysis
- Photoreceptor and optogenetics research
- Photonic Crystal and Fiber Optics
- Spectroscopy Techniques in Biomedical and Chemical Research
- Magnetism in coordination complexes
- Advanced Fluorescence Microscopy Techniques
- Advancements in Photolithography Techniques
Universität Hamburg
2017-2025
Photonics (United States)
2022-2025
Hamburg Institut (Germany)
2024
Institute for Experimental Psychophysiology (Germany)
2021
Weatherford College
2021
Holoeye Photonics (Germany)
2020
Helmholtz Institute Jena
2012-2019
Deutsches Elektronen-Synchrotron DESY
2019
Max Planck Institute for the Structure and Dynamics of Matter
2019
Hamburg Centre for Ultrafast Imaging
2019
Dynamic nuclear polarization (DNP) at high magnetic fields (9.2 T, 400 MHz 1H NMR frequency) requires microwave power sources to achieve saturation of the EPR transitions. Here we describe first high-field liquid-state DNP results using a high-power gyrotron source (20 W 260 GHz). A enhancement −29 on water protons was obtained for an aqueous solution Fremy's Salt; in comparison previous highest value −10 solid-state (maximum 45 mW). The increased enhancements are partly due larger and...
Unexpected high DNP enhancements of more than 10 have been achieved in liquid water samples at room temperature and magnetic fields 9.2 T (corresponding to 400 MHz 1H NMR frequency 260 GHz EPR frequency). The were polarized situ using a double-resonance structure, which allows simultaneous excitation transitions achieves significant very low incident microwave power only 45 mW. These results demonstrate the first important step toward application high-resolution NMR, increasing sensitivity...
FERMI is a novel class of free-electron laser that capable producing femtosecond pulses ultraviolet and x-ray light, essential to studying ultrafast processes in matter. A new investigation characterizes FERMI's pulse shape confirms it routinely generates Gaussian lasting few tens femtoseconds.
The magnetic resonance signal obtained from nuclear spins is strongly affected by the presence of nearby electronic spins. This effect finds application in biomedical imaging and structural characterization large biomolecules. In many these applications nitroxide free radicals are widely used due to their non-toxicity versatility as site-specific spin labels. We perform molecular dynamics simulations study electron–nucleus interaction radical TEMPOL water atomistic detail. Correlation...
The potential of borate crystals, BBO, LBO and BiBO, for high average power scaling optical parametric chirped-pulse amplifiers is investigated. Up-to-date measurements the absorption coefficients at 515 nm thermal conductivities are presented. measured a factor 10-100 lower than reported by literature BBO LBO. For large variation was found between crystals from different manufacturers. linear nonlinear as well were determined first time BiBO. Further, crystal cooling methods In addition,...
Optical parametric chirped-pulse amplifiers with high average power are possible novel high-power Yb:YAG kW-level output powers. We demonstrate a compact wavelength-tunable sub-30-fs amplifier 11.4 W 20.7% pump-to-signal conversion efficiency. For amplification, beta-barium borate crystal is pumped by 140 W, 1 ps InnoSlab at 3.25 MHz repetition rate. The broadband seed generated via supercontinuum generation in YAG crystal.
Vibrational modes of glucose spanning from 900 to 1400 cm −1 in the molecular fingerprint region have been traced by means vibrational sum-frequency generation spectroscopy aqueous solution as a function concentration. The high sensitivity is enabled 200 kHz few-cycle mid-infrared optical parametric chirped-pulse amplifier (OPCPA). OPCPA generates broadband pulses (from 7 11 μ m) centered at 9 m with 114 fs pulse duration, average power 245 mW and energy 1.2 J. achieved performance...
An Yb:YAG thin-disk multipass laser amplifier system was developed operating in a 10 Hz burst operation mode with 800 µs duration and 100 kHz intra-burst repetition rate. Methods for the suppression of parasitic amplified spontaneous emission are presented. The average output pulse energy is up to 44.5 mJ 820 fs compressed duration. power 4.45 kW during highest reported this type amplifier.
High repetition rate free-electron lasers (FEL), producing highly intense extreme ultraviolet and x-ray pulses, require new high power tunable femtosecond for FEL seeding pump-probe experiments. A tunable, 112 W (burst mode) optical parametric chirped-pulse amplifier (OPCPA) is demonstrated with center frequencies ranging from 720–900 nm, pulse energies up to 1.12 mJ a duration of 30 fs at 100 kHz. Since the scalability this OPCPA limited by OPCPA-pump amplifier, we also demonstrate 6.7–13.7...
The interaction between nuclear and electronic spins is of interest for structural characterization biomolecules biomedical imaging based on magnetic resonance. polarization the can be increased significantly if electron spin kept out equilibrium. We employ semiclassical relaxation theory to analyze two-spin system characteristic nitroxide radicals. Atomistic molecular dynamics simulations TEMPOL in water are performed account effects tumbling spin-rotation coupling spin–spin spin–lattice...
The long-term stability of optical parametric chirped-pulse amplifiers is hindered by thermal path length drifts affecting the temporal pump-to-signal overlap. A kilowatt-pumped burst amplifier presented delivering broadband 1.4 mJ pulses with a spectral bandwidth supporting sub-7 fs pulse duration. Active overlap control can be achieved feedback timing signals from cross-correlation or measurements. Using balanced cross-correlator, we achieve synchronization residual jitter only (46 ± 2)...
A conceptual design of a high power, ultrabroadband optical parametric chirped-pulse amplifier (OPCPA) was carried out comparing nonlinear crystals (LBO and BBO) for 810 nm centered, sub-7.0 fs pulses with energies above 1 mJ. These amplifiers are only possible parallel development kilowatt-level OPCPA-pump amplifiers. It is therefore important to know good strategies use the available energy efficiently. Numerical simulations, including self- cross-phase modulation, were used investigate...
Using a newly designed liquid-state dynamic nuclear polarization (DNP) spectrometer operating at magnetic field of 9.2 T, DNP enhancement −4.0(1) was achieved for protons in liquid water-TEMPOL sample. The mechanism observed to be the Overhauser effect, where transfered via electron–proton dipolar relaxation. At full microwave power, sample heated by 17 K above room temperature, causing significant increase enhancement. These first results from Frankfurt represent step towards application...
Recent studies confirmed that the materials used in extreme UV and soft X-ray regime for precise characterization of intense free-electron laser pulses (e.g., Si3N4) do not work efficiently hard regime, which is due to fact impact a photon followed by series electron cascading processes. Following theoretical indication, we show this limitation can be circumvented time significantly reduced if energy double ionization energy. We investigate an alternative material pulse diagnostics, SnO2,...
A total output power of 14 kW is presented in a burst operation mode at 100 kHz intra-burst repetition rate from two-stage cascaded thin-disk multipass amplifier. This yields pulse energy 140 mJ.
The dream of physico-chemists to control molecular reactions with light beyond electronic excitations pushes the development laser pulse shaping capabilities in midinfrared (MIR) spectral range.Here, we present a compact optical parametric amplifier platform for generation and MIR pulses wavelength range between 8 µm 15 µm.Opportunities judiciously tailoring electromagnetic waveform are investigated, demonstrating field resolution 59 GHz at total bandwidth 5 THz.In experiments focusing on...
Optical properties of mid-infrared, Li-based nonlinear crystals (NLC) are estimated under realistic experimental conditions for high power lasers using the thermal imaging method.The study focuses on with relatively large apertures energy and applications that transparent in a broad spectral range (6-16 µm).For this purpose, average Yb:YAG laser amplifier system was used pumps response materials recorded.An estimate linear absorption coefficients different non-oxide at 1-µm pump wavelength...
An improved dual-gas quasi-phase matching (QPM) foil target for high harmonic generation (HHG) is presented. The can be setup with 12 individual gas inlets each feeding multiple nozzles separated by a minimum distance of 10 μm. Three-dimensional density profiles these jets were measured using Mach-Zehnder Interferometer. These measurements reveal how the influence in adjacent and this leads to increased local densities. analysis shows that are well defined up about 300 μm from orifice. This...