A5031166491- Advanced X-ray Imaging Techniques
- Particle Accelerators and Free-Electron Lasers
- Laser-Plasma Interactions and Diagnostics
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Electron Microscopy Techniques and Applications
- Corneal surgery and disorders
- Adaptive optics and wavefront sensing
- Intraocular Surgery and Lenses
- Advancements in Photolithography Techniques
- Nuclear Physics and Applications
- Image Processing Techniques and Applications
- Advanced X-ray and CT Imaging
- Glaucoma and retinal disorders
- Electron and X-Ray Spectroscopy Techniques
- Crystallography and Radiation Phenomena
- Digital Holography and Microscopy
- Laser-induced spectroscopy and plasma
- Astrophysical Phenomena and Observations
- Corneal Surgery and Treatments
- Ophthalmology and Visual Impairment Studies
SCHWIND eye-tech-solutions (Germany)
2024
Deutsches Elektronen-Synchrotron DESY
2019-2022
European X-Ray Free-Electron Laser
2018-2019
Hamburg Centre for Ultrafast Imaging
2017
Max Planck Institute for the Structure and Dynamics of Matter
2017
Universität Hamburg
2017
The routine atomic resolution structure determination of single particles is expected to have profound implications for probing structure-function relationships in systems ranging from energy-storage materials biological molecules. Extremely bright ultrashort-pulse X-ray sources - free-electron lasers (XFELs) provide X-rays that can be used probe ensembles nearly identical nanoscale particles. When combined with coherent diffractive imaging, these objects imaged; however, as the images...
In this work, single-shot ptychography was adapted to the XUV range and, as a proof of concept, performed at free-electron laser FLASH DESY obtain high-resolution reconstruction test sample. Ptychography is coherent diffraction imaging technique capable extended samples with diffraction-limited resolution. However, its scanning nature makes time-consuming and also prevents application for mapping dynamical processes. Single-shot can be realized by collecting patterns multiple overlapping...
Ptychography, a scanning coherent diffraction imaging method, can produce high-resolution reconstruction of sample and, at the same time, illuminating beam. The emergence vacuum ultraviolet and X-ray free electron lasers (FELs) has brought sources with unprecedented characteristics that enable ptychography highly intense ultra-fast short-wavelength pulses. However, shot-to-shot pulse fluctuations typical for FEL pulses particularly partial spatial coherence self-amplified spontaneous...
The Zernike representation of wavefronts interlinks low- and high-order aberrations, which may result in imprecise clinical estimates. Recently, the Gatinel–Malet wavefront has been introduced to resolve this problem by deriving a new, unlinked basis originating from polynomials. This new preserves classical low high aberration subgroups’ structure, as well orthogonality within each subgroup, but not between aberrations. feature led conversions relying on separate reconstructions for...
Abstract We measured the transverse coherence at FLASH2, a variable gap undulator line FLASH free-electron laser user facility DESY in Hamburg. demonstrate, theoretically and experimentally, revised version of Young’s double pinhole approach to perform single-shot, repeatable non-invasive measurements. At beamline FL24 pulses was systematically characterized wavelengths 8, 13.5 18 nm for different FEL source settings. determine degrees 57% 87% vertical horizontal direction, respectively....
The PERCIVAL detector is a CMOS imager designed for the soft X-ray regime at photon sources. Although still in its final development phase, it has recently seen first user experiments: ptychography free-electron laser, holographic imaging storage ring and preliminary tests on correlation spectroscopy. performed remarkably well terms of spatial resolution achievable sample plane, owing to small pixel size, large active area very dynamic range; but also frame rate, which significantly faster...
Optical coherence tomography (OCT) has gained momentum on segmenting anterior corneal substructures, such as treatment-induced flaps and lenticule cuts created by femtosecond lasers. However, recent semi-automated methods rely manual markers, which can introduce bias variability. In this work, we present an automated algorithm designed to overcome the limitations in geometric quantification of intrastromal produced two different lasers, using a unique imaging system. Our analysis, conducted...
Determining fluctuations in focus properties is essential for many experiments at Self-Amplified-Spontaneous-Emission (SASE) based Free-Electron-Lasers (FELs), particular imaging single non-crystalline biological particles. We report on a diffractive technique to fully characterize highly focused, single-shot pulses using an iterative phase retrieval algorithm, and benchmark it against existing Hartmann wavefront sensor. The results, both theoretical experimental, demonstrate the...
Wavefront-propagation simulations have been performed to complete the design of a monochromator beamline for FLASH2, variable-gap undulator line at soft X-ray free-electron laser in Hamburg (FLASH). Prior propagation through optical elements, parameters photon source were generated using GENESIS code which includes experimental data. Threshold tolerances misalignment mirror angles are calculated and, since diffraction effects included simulations, minimum quality with respect slope errors...
Abstract Ptychograhy is a scanning coherent diffraction imaging technique capable of providing images extended samples with diffraction-limited resolution. However, ptychography experiments are time-consuming due to their nature which also prevents use for dynamical processes. Recently, setups based on two con-focal lenses were proposed perform single-shot in the visible regime by measuring pattern produced multiple overlapping beams one shot. this approach cannot be straightforwardly X-ray...
Polyethylene terephthalate (PET) is a thermoplastic polyester with numerous applications in industry. However, it requires surface modification on an industrial scale for printing and coating processes plasma treatment one of the most commonly used techniques to increase hydrophilicity PET films. Systematic improvement by adaption process can be aided comprehensive understanding morphology chemistry. imaging large areas (tens microns) resolution that allows quality challenging. As...
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The free-electron laser FLASH2, a variable gap undulators line, has opened new scientific possibilities for users at DESY in the Hamburg area [1]. current pulsed radiation FLASH facility primarily relies on SASE process. Thus, beam characteristics may differ drastically from pulse to pulse; requiring single-shot photon diagnostics and characterization of parameters. beamline FL24 FLASH2 is equipped with set bendable Kirkpatrick-Baez (KB) mirrors which can strongly focus down few micrometers....