A5025033770- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Laser-Matter Interactions and Applications
- Atomic and Molecular Physics
- Laser Material Processing Techniques
- Semiconductor Lasers and Optical Devices
- Advanced X-ray Imaging Techniques
- Laser Design and Applications
- Photonic and Optical Devices
- Ion-surface interactions and analysis
- Advanced Fiber Laser Technologies
- Ultrasound and Cavitation Phenomena
- Advanced Fiber Optic Sensors
- Diamond and Carbon-based Materials Research
- High-pressure geophysics and materials
- Particle Accelerators and Free-Electron Lasers
- Integrated Circuits and Semiconductor Failure Analysis
- Advanced optical system design
- Photography and Visual Culture
- Nanofabrication and Lithography Techniques
- Fluid Dynamics and Mixing
- Advanced Electron Microscopy Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Solid State Laser Technologies
- Satellite Image Processing and Photogrammetry
University of Applied Sciences Emden Leer
2014-2023
Carl von Ossietzky Universität Oldenburg
2013-2023
Heidelberg University
1992-2023
Fraunhofer Institute for Microengineering and Microsystems
2004-2023
École Polytechnique
2001-2023
Deutsches Elektronen-Synchrotron DESY
2015
Jade University of Applied Sciences
2009
Carl Zeiss (Germany)
2004-2006
University of Duisburg-Essen
2006
Max Planck Society
1990-2005
The investigation of high-order harmonic generation (HHG) femtosecond laser pulses by means laser-produced plasmas is surveyed. This kind an alternative to the HHG in gases and shows significantly higher conversion efficiency. Furthermore, with plasma targets there no limitation on applicable intensity thus generated harmonics can be much more intense. In principle, light may also at relativistic intensity, which case their intensities even exceed that focused pulse many orders magnitude....
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.
Plasmas were generated by 400 fs KrF laser pulses at intensities of \ensuremath{\sim}${10}^{17}$ W ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$ on aluminum targets. Reflectivity and x-ray emission measured as a function polarization, angle incidence, intensity. For the same absorbed intensity, p-polarized light is up to factor 5 more efficient in generating x rays (>0.5 keV) than s-polarized light. These results show importance an additional absorption process, besides collisional...
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,...
This paper discusses the generation of high-order optical harmonics from solid targets using laser pulses 35 and 120 femtoseconds. Harmonics up to 35th order were observed. High conversion efficiency has been achieved, e.g., ${10}^{\ensuremath{-}6}$ $10\mathrm{th}$ harmonic. It is demonstrated that harmonic emission highly directional decreases rapidly with increasing plasma scale length.
High-order harmonic generation from a solid target surface has been investigated using femtosecond laser pulses focused to intensities greater than ${10}^{18}{\mathrm{W}/\mathrm{c}\mathrm{m}}^{2}.$ The experiments show that the harmonics are very intense, with conversion efficiency is one or two orders of magnitude larger generated in gases. Beside observation presently shortest wavelength femtosecond-laser interaction, i.e., down 22 nm, an anomaly observed spectrum. In contrast expected...
The harmonic emission from thin solid carbon and aluminum foils, irradiated by 150 fs long frequency-doubled Ti:sapphire laser pulses at $\ensuremath{\lambda}=395\text{ }\text{ }\mathrm{nm}$ peak intensities of a few ${10}^{18}\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$, has been studied. In addition to the harmonics emitted front side in specular direction, we observe up 10th order, including fundamental rear direction incident beam, while foil is still strongly overdense. experimental...
Using a high-power femtosecond frequency-doubled Nd:glass laser system with contrast ratio of ${10}^{12}$, the interaction between light and matter up to intensities ${10}^{19}$ W cm${}^{\ensuremath{-}2}$has been investigated. The absorption in solid aluminum is almost independent polarization, peaks at about 25$\ifmmode^\circ\else\textdegree\fi{}$, reaches values 45%. Assuming an exponential electron distribution, temperature 420 keV $4\ifmmode\times\else\texttimes\fi{}{10}^{18}$...
The interaction of femtosecond ${\mathrm{KrF}}^{\mathrm{*}}$-laser pulses with plasmas various solid target materials has been studied up to intensities exceeding ${10}^{18}$ W/${\mathrm{cm}}^{2}$. Absorption measurements were performed for p- ands-polarized laser light and as a function the intensity angle incidence. They reveal substantial absorption 70% even at in excess ${10}^{18}$W/${\mathrm{cm}}^{2}$. results have also compared simulations high and, particular, peaking large angles...
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...
A novel spectrograph comprised of a transmission grating, toroidal mirror, and microchannel plate detector is presented here. It capable detecting spectra in the wavelength range from 5 to 150 Å with resolution about 1.5 Å. Owing it high efficiency, even an x-ray spectrum low-energy laser produced plasma, i.e., emission order 10−10 J/sr, can be measured single shot.
We investigate the generation of ultrashort Kalpha pulses from plasmas produced by intense femtosecond p-polarized laser on Copper and Titanium targets. Particular attention is given to interplay between angle incidence beam target a controlled prepulse. It observed experimentally that yield can be optimized for correspondingly different prepulse plasma scale-length conditions. For steep electron-density gradients, maximum yields achieved at larger angles. somewhat expanded expected in case...
Solid state density aluminum and carbon plasmas were generated by 350 fs KrF laser pulses at intensities of 1017 W cm−2. Reflectivity, x-ray emission, spectra the backscattered radiation measured as a function polarization, angle incidence, intensity (I). For p-polarized light, absorption (A) is almost independent for 1015 cm−2<I<2×1017 cm−2, can reach values up to A=0.8. constant intensity, light factor 15 more efficient in generating x rays than s-polarized light. A...
Soft x-ray spectra generated on flat Al targets by a 500 fs KrF* laser pulse (intensity 5.3×1015 W/cm2), preceded prepulse of the same duration, have been measured as function separation and intensity. It was found that not only total emission much stronger when present but, in particular, lines shorter wavelength region had higher intensity than without prepulse, were strongly dependent time between main pulse.
The interaction of high-intensity subpicosecond KrF*-laser pulses with aluminum plasmas has been investigated. laser pulse absorption and the x-ray production have related at a series intensities up to 1017 W/cm2 different angles incidence. Soft spectra were measured in wavelength range from 7 150 Å various spectrographs. show distinct dependences on intensity, polarization, angle observed dependence intensity incidence is result both angular that conversion efficiency absorbed energy into...
The interaction of high-intensity subpicosecond KrF*-laser pulses with aluminium plasmas is investigated at intensities between 1014 and 1017 W/cm2. Using a one-dimensional hydrocode, the laser energy absorption time evolution plasma parameters have been studied as function intensity, incidence angle, polarization. Complementary particle-in-cell simulations also performed to check collisionless component carried by hot electrons ions. These are compared previous experiments on pulse x-ray generation.
Absorption of L-M and L-N transitions nickel has been measured using point projection spectroscopy. The x-ray radiation from laser-irradiated gold cavities was used to heat volumetrically foils "tamped with carbon" up 20 eV. Experimental spectra have analyzed calculations based on the spin-orbit split arrays statistical approach performed for each ionic species Ni5+ Ni11+. Using a least-squares fit, this method provides an ion distribution broader than at local thermodynamic equilibrium,...
The emission of fundamental and harmonic radiation from the rear side thin foils in thickness range 50-460 nm irradiated by intense frequency doubled Ti:sapphire laser pulses duration 150 fs intensities up to a few 10(18) W/cm(2) was investigated. Following previous study [Teubner, Phys. Rev. Lett. 92, 185001 (2004)], we measured efficiencies, polarization properties, spectral shapes second harmonic. Rear is only observed when obliquely incident light p -polarized. Particle-in-cell (PIC)...