Krüger, Sven Philip

[["dc.bibliographiccitation.artnumber","035008"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","New Journal of Physics"],["dc.bibliographiccitation.volume","12"],["dc.contributor.affiliation","Giewekemeyer, K;"],["dc.contributor.affiliation","Neubauer, H;"],["dc.contributor.affiliation","Kalbfleisch, S;"],["dc.contributor.affiliation","Krüger, S P;"],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Neubauer, Heike"],["dc.contributor.author","Kalbfleisch, Sebastian"],["dc.contributor.author","Krueger, S. P."],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:46:08Z"],["dc.date.available","2017-09-07T11:46:08Z"],["dc.date.issued","2010"],["dc.date.updated","2022-02-09T21:48:01Z"],["dc.description.abstract","We report on lensless nanoscale imaging using x-ray waveguides as ultra-small sources for quasi-point-like illumination. We first give a brief account of the basic optical setup, an overview of the progress in waveguide fabrication and characterization, as well as the basics of image formation. We then compare one-step holographic and iterative ptychographic reconstruction, both for simulated and experimental data collected on samples illuminated by waveguided beams. We demonstrate that scanning the sample with partial overlap can substantially improve reconstruction quality in holographic imaging, and that divergent beams make efficient use of the limited dynamic range of current detectors, regardless of the reconstruction scheme. Among different experimental settings presented, smallest source dimensions of 29 nm (horizontal) x 17 nm have been achieved, using multi-modal interference effects. These values have been determined by ptychographic reconstruction of a Ta test structure at 17.5 keV and have been corroborated by simulations of field propagation inside the waveguide."],["dc.identifier.doi","10.1088/1367-2630/12/3/035008"],["dc.identifier.eissn","1367-2630"],["dc.identifier.fs","568205"],["dc.identifier.gro","3142948"],["dc.identifier.isi","000276349600007"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/6673"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/408"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","1367-2630"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.rights","Goescholar"],["dc.rights.uri","https://goedoc.uni-goettingen.de/licenses"],["dc.subject.gro","x-ray optics"],["dc.subject.gro","x-ray imaging"],["dc.title","Holographic and diffractive x-ray imaging using waveguides as quasi-point sources"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","9656"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","Optics Express"],["dc.bibliographiccitation.lastpage","9675"],["dc.bibliographiccitation.volume","19"],["dc.contributor.author","Salditt, Tim"],["dc.contributor.author","Kalbfleisch, Sebastian"],["dc.contributor.author","Osterhoff, Markus"],["dc.contributor.author","Krueger, S. P."],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Neubauer, Heike"],["dc.contributor.author","Sprung, Michael"],["dc.date.accessioned","2020-11-05T15:05:24Z"],["dc.date.available","2020-11-05T15:05:24Z"],["dc.date.issued","2011"],["dc.description.abstract","We have studied the spatial coherence properties of a nano-focused x-ray beam by grating (Talbot) interferometry in projection geometry. The beam is focused by a fixed curvature mirror system optimized for high flux density under conditions of partial coherence. The spatial coherence of the divergent exit wave emitted from the mirror focus is measured by Talbot interferometry The results are compared to numerical calculations of coherence propagation. In view of imaging applications, the magnified in-line image of a test pattern formed under conditions of partial coherence is analyzed quantitatively. Finally, additional coherence filtering by use of x-ray waveguides is demonstrated. By insertion of x-ray waveguides, the beam diameter can be reduced from typical values of 200 nm to values below 15 nm. In proportion to the reduction in the focal spot size, the numerical aperture (NA) of the projection imaging system is increased, as well as the coherence length, as quantified by grating interferometry. (C) 2011 Optical Society of America"],["dc.identifier.doi","10.1364/OE.19.009656"],["dc.identifier.gro","3142728"],["dc.identifier.isi","000290490200090"],["dc.identifier.pmid","21643224"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7504"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/68458"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-352.6"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation","SFB 755: Nanoscale Photonic Imaging"],["dc.relation.eissn","1094-4087"],["dc.relation.issn","1094-4087"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.rights","Goescholar"],["dc.rights.uri","https://goedoc.uni-goettingen.de/licenses"],["dc.subject.gro","x-ray optics"],["dc.subject.gro","x-ray imaging"],["dc.title","Partially coherent nano-focused x-ray radiation characterized by Talbot interferometry"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","10"],["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Optical Nanoscopy"],["dc.bibliographiccitation.lastpage","7"],["dc.bibliographiccitation.volume","1"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Priebe, Marius"],["dc.contributor.author","Wilke, Robin N."],["dc.contributor.author","Krüger, Sven P"],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Kalbfleisch, Sebastian"],["dc.contributor.author","Olendrowitz, Christian"],["dc.contributor.author","Sprung, Michael"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:54:07Z"],["dc.date.available","2017-09-07T11:54:07Z"],["dc.date.issued","2012"],["dc.description.abstract","We have imaged the three-dimensional density distribution of unstained and unsliced, freeze-dried cells of the gram-positive bacterium Deinococcus radiodurans by tomographic x-ray propagation microscopy, i.e. projection tomography with phase contrast formation by free space propagation. The work extends previous x-ray imaging of biological cells in the simple in-line holography geometry to full three-dimensional reconstruction, based on a fast iterative phase reconstruction algorithm which circumvents the usual twin-image problem. The sample is illuminated by the highly curved wave fronts emitted from a virtual quasi-point source with 10 nm cross section, realized by two crossed x-ray waveguides. The experimental scheme allows for a particularly dose efficient determination of the 3D density distribution in the cellular structure."],["dc.identifier.doi","10.1186/2192-2853-1-10"],["dc.identifier.fs","593648"],["dc.identifier.gro","3145116"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9581"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/2817"],["dc.language.iso","en"],["dc.notes","Funding by the DFG collaborative research center SFB 755\r\nNanoscale Photonic Imaging and the German Ministry of Education and\r\nResearch (Grant No. 05K10MGA) is gratefully acknowledged."],["dc.notes.intern","Crossref Import"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.relation.issn","2192-2853"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.subject.gro","x-ray imaging"],["dc.subject.gro","biomedical tomography"],["dc.title","Low-dose three-dimensional hard x-ray imaging of bacterial cells"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]