A5064425484- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Mass Spectrometry Techniques and Applications
- Spectroscopy and Quantum Chemical Studies
- Photonic and Optical Devices
- Advanced Chemical Physics Studies
- Laser-Plasma Interactions and Diagnostics
- Force Microscopy Techniques and Applications
- Advanced Surface Polishing Techniques
- Laser Design and Applications
- DNA and Nucleic Acid Chemistry
- Integrated Circuits and Semiconductor Failure Analysis
- Strong Light-Matter Interactions
- Mechanical and Optical Resonators
- Antibiotic Resistance in Bacteria
- Advanced biosensing and bioanalysis techniques
- Laser Material Processing Techniques
- Advanced Fluorescence Microscopy Techniques
- Advanced Electron Microscopy Techniques and Applications
- Nonlinear Dynamics and Pattern Formation
- Terahertz technology and applications
- Bacterial Genetics and Biotechnology
- Click Chemistry and Applications
- Solid State Laser Technologies
- Hemoglobinopathies and Related Disorders
TU Dresden
2005-2015
Lund University
2006-2013
We study photoionization of argon atoms excited by attosecond pulses using an interferometric measurement technique. measure the difference in time delays between electrons emitted from 3s(2) and 3p(6) shell, at different excitation energies ranging 32 to 42 eV. The determination photoemission requires taking into account process, involving interaction with a probing infrared field. This contribution can be estimated universal formula is found for substantial fraction measured delay.
Over the past years, bottom-up bionanotechnology has been developed as a promising tool for future technological applications. Many of these biomolecule-based assemblies are characterized using various single-molecule techniques that require strict anaerobic conditions. The most common oxygen scavengers experiments glucose oxidase and catalase (GOC) or protocatechuate dioxygenase (PCD). One pitfalls systems, however, is production carboxylic acids. These acids can result in significant pH...
We present an interferometric pump-probe technique for the characterization of attosecond electron wave packets (WPs) that uses a free WP as reference to measure bound WP. demonstrate our method by exciting helium atoms using pulse (AP) with bandwidth centered near ionization threshold, thus creating both and simultaneously. After variable delay, is ionized few-cycle infrared laser precisely synchronized original AP. By measuring delay-dependent photoelectron spectrum we obtain interferogram...
We study resonant two-color two-photon ionization of helium via the 1s3p (1)P(1) state. The first color is 15th harmonic a tunable Ti:sapphire laser, while second fundamental laser radiation. Our method uses phase-locked high-order harmonics to determine phase process by interferometry. measurement variation as function detuning from resonance and intensity dressing field allows us dependence transition energy.
We demonstrate a quantum stroboscope based on sequence of identical attosecond pulses that are used to release electrons into strong infrared (IR) laser field exactly once per cycle. The resulting electron momentum distributions recorded as function time delay between the IR and pulse train using velocity map imaging spectrometer. Because our creates wave packets, single ionization event can be studied stroboscopically. This technique has enabled us image coherent scattering takes place when...
We present a combined theoretical and experimental study of ultrafast wave-packet dynamics in the dissociative ionization H_{2} molecules as result irradiation with an extreme-ultraviolet (XUV) pulse followed by infrared (IR) pulse. In experiments where duration both XUV IR pulses are shorter than vibrational period H_{2};{+}, dephasing rephasing wave packet that is formed H_{2};{+} upon neutral molecule observed. exceeds (15 fs), pronounced dependence H;{+} kinetic energy distribution on...
We present a hybrid single-molecule technique combining magnetic tweezers and Förster resonance energy transfer (FRET) measurements. Through applying external forces to paramagnetic sphere, we induce conformational changes in DNA nanostructures, which are detected two output channels simultaneously. First, by tracking bead with high spatial temporal resolution, observe overall length along the force axis. Second, measured FRET efficiency between fluorescent probes monitors local changes. The...
We investigate the dynamics of organic laser guest-host composite tris-(8-hydroxy quinoline) aluminium and 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran embedded in a high-Q (Q≈4500) double distributed Bragg reflector microcavity using subpicosecond up-conversion techniques. Lasing is observed at threshold 0.4nJ∕20μJcm−2 with linewidth 0.05 nm (resolution limit). observe strongly nonlinear intensity-dependent delay emitted radiation burst. All experimental results are...
We use semiconductor (Si) and metallic (Al, Zr) transmission filters to shape, in amplitude phase, high-order harmonics generated from the interaction of an intense titanium sapphire laser field with a pulsed neon gas target. Depending on properties filter, emitted attosecond pulses can be optimized bandwidth and/or pulse length. demonstrate generation centered at energies 50 80 eV, bandwidths as large 45 eV durations compressed 130 as.
We use a strong two-colour laser field composed of the fundamental (800 nm) and second harmonic (400 an infrared (IR) to generate attosecond pulses with controlled spectral temporal properties. With second-harmonic intensity equal 15% IR is enough significantly alter control electron trajectories in generation process. This enables us tune central photon energy by changing phase difference between fields. In time domain radiation emitted as sequence separated full cycle. also perform...
We study experimentally the influence of intensity infrared (IR) probe field on attosecond pulse train (APT) phase measurements performed with RABITT method (Reconstruction Attosecond Beating by Interference in Two-Photon Transitions). find that if a strong IR is applied, pulses will appear to have lower-than-actual chirp rates. also observe onset streaking regime breakdown weak-field conditions. perform Fourier-analysis harmonic and sideband continuum states show mutual relation harmonics...
Received 13 April 2011DOI:https://doi.org/10.1103/PhysRevLett.106.169904© 2011 American Physical Society
We present a method for performing quantum state holography, with which we completely characterize the amplitude and phase of an attosecond electron wave packet. Our approach is extension recent publication [J. Mauritsson et al., Phys. Rev. Lett. 105, 053001 (2010)] in demonstrated experimentally that energies amplitudes packet can be characterized using interferometry. Here show theoretically interferometry extended to retrieve phases all states make up demonstrate feasibility our by...
We examine how the generation and propagation of high-order harmonics in a partly ionized gas medium affect their strength synchronization. The temporal properties resulting attosecond pulses generated long targets can be significantly influenced by macroscopic effects, particular intensity degree ionization which control dispersion. Under some conditions, use longer than absorption length lead to compressed pulses. show these effects experimentally, using 6 mm-long argon-filled cell as...
We characterize attosecond pulses in a train using both the well established ``reconstruction of beating by interference two-photon transitions'' (RABITT) technique and recently demonstrated situ method, which is based on weak perturbation harmonic generation process second laser field. The latter determines characteristics single atom emission, while RABITT allows one to measure ``on target.'' By comparing results two methods, influence propagation filtering can be extracted.
Kerf-free wafering techniques hold the potential to drastically reduce material losses in semiconductor manufacturing processes. Spalling processes use externally applied stresses separate crystalline materials along crystal planes with well-defined thickness. Spalled substrates, however, exhibit striations from crack propagation crystal, a pattern called Wallner lines. Here, we demonstrate process that scales favorably for SiC substrates starting 1 inch diameter. To eliminate line pattern,...
We report on the results of intense third party evaluation COLD SPLIT technology. In total nine different SiC manufactures supplied test material. The confirm tremendous potential technology with kerf losses per wafer less than 100μm. Furthermore, our general approach led to comparable for all vendors. vendor specific difference like lateral doping level were addressed via control loops in lasering process. These take crystal properties into account and adjust applied laser energy depth...
We report the experimental observation of polarization splitting at normal incidence and terahertz oscillations transmitted light from a single planar microcavity. Optical anisotropy in SiO2∕TiO2-dielectric mirrors leads to two perpendicularly polarized transmission modes. ascribe oblique columnar structures dielectrics resulting off-axial growth microcavity structure. apply an up-conversion setup for temporally spectrally resolved measurements obtain corresponding beating 1.25THz. Time...
We present experiments on the control over spectral amplitude and phase of attosecond pulses, using metallic semiconductor thin-film dispersive filters. A pulse duration as short 130 is obtained.
The authors present time-resolved studies of laser emission from an organic microcavity filled with a guest-host composite tris(8-hydroxy quinoline) aluminium and 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran. A line splitting 0.18THz between two perpendicularly polarized lines is observed, resulting optical anisotropy in the distributed Bragg reflectors. This particular behavior attributed to oblique columnar structures shaped by off-axial preparatory conditions. By means...