Zayko, Sergey

[["dc.bibliographiccitation.firstpage","239"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Optica"],["dc.bibliographiccitation.lastpage","242"],["dc.bibliographiccitation.volume","3"],["dc.contributor.author","Zayko, Sergey"],["dc.contributor.author","Sivis, Murat"],["dc.contributor.author","Schäfer, Sascha"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2020-12-10T18:42:03Z"],["dc.date.available","2020-12-10T18:42:03Z"],["dc.date.issued","2016"],["dc.description.abstract","The optical polarization response of a structured material is one of its most significant properties, carrying information about microscopic anisotropies as well as chiral features and spin orientations. Polarization analysis is therefore a key element of imaging and spectroscopy techniques throughout the entire spectrum. In the case of extreme ultraviolet (EUV) radiation, however, both the preparation and detection of well-defined polarization states remain challenging. As a result, polarization-sensitive EUV microscopy based on table-top sources has not yet been realized, despite its great potential, for example, in nanoscale magnetic imaging. Here, we demonstrate polarization contrast in coherent diffractive imaging using high harmonic radiation and investigate the polarization properties of nanoscale transmission waveguides. We quantify the achievable polarization extinction ratio for different waveguide geometries and wavelengths. Our results demonstrate the utility of slab waveguides for efficient EUV polarization control and illustrate the importance of considering polarization contrast in the imaging of nanoscale structures. (C) 2016 Optical Society of America"],["dc.identifier.doi","10.1364/OPTICA.3.000239"],["dc.identifier.eissn","2334-2536"],["dc.identifier.isi","000372339500005"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/77788"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","2334-2536"],["dc.title","Polarization contrast of nanoscale waveguides in high harmonic imaging"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","501"],["dc.bibliographiccitation.lastpage","522"],["dc.bibliographiccitation.seriesnr","134"],["dc.contributor.author","Zayko, Sergey"],["dc.contributor.author","Kfir, Ofer"],["dc.contributor.author","Ropers, Claus"],["dc.contributor.editor","Salditt, Tim"],["dc.contributor.editor","Egner, Alexander"],["dc.contributor.editor","Luke, D. Russell"],["dc.date.accessioned","2021-04-21T11:15:37Z"],["dc.date.available","2021-04-21T11:15:37Z"],["dc.date.issued","2020"],["dc.identifier.doi","10.1007/978-3-030-34413-9_18"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/84275"],["dc.relation","SFB 755: Nanoscale Photonic Imaging"],["dc.relation.crisseries","Topics in Applied Physics"],["dc.relation.doi","10.1007/978-3-030-34413-9"],["dc.relation.eisbn","978-3-030-34413-9"],["dc.relation.isbn","978-3-030-34412-2"],["dc.relation.ispartof","Nanoscale Photonic Imaging"],["dc.relation.ispartofseries","Topics in Applied Physics; 134"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.subject.gro","SFB 755"],["dc.title","Polarization-Sensitive Coherent Diffractive Imaging Using HHG"],["dc.type","book_chapter"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","19911"],["dc.bibliographiccitation.issue","15"],["dc.bibliographiccitation.journal","Optics Express"],["dc.bibliographiccitation.lastpage","19921"],["dc.bibliographiccitation.volume","23"],["dc.contributor.author","Zayko, Sergey"],["dc.contributor.author","Moennich, Eike"],["dc.contributor.author","Sivis, Murat"],["dc.contributor.author","Mai, Dong-Du"],["dc.contributor.author","Salditt, Tim"],["dc.contributor.author","Schaefer, Sascha"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2017-09-07T11:43:40Z"],["dc.date.available","2017-09-07T11:43:40Z"],["dc.date.issued","2015"],["dc.description.abstract","We study extreme-ultraviolet wave propagation within optically thick nanostructures by means of high-resolution coherent diffractive imaging using high-harmonic radiation. Exit waves from different objects are reconstructed by phase retrieval algorithms, and are shown to be dominated by waveguiding within the sample. The experiments provide a direct visualization of extreme-ultraviolet guided modes, and demonstrate that multiple scattering is a generic feature in extruded nanoscale geometries. The observations are successfully reproduced in numerical and semi-analytical simulations. (C) 2015 Optical Society of America"],["dc.identifier.doi","10.1364/OE.23.019911"],["dc.identifier.gro","3141860"],["dc.identifier.isi","000361035300131"],["dc.identifier.pmid","26367651"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/1878"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["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.subject.gro","x-ray optics"],["dc.subject.gro","x-ray imaging"],["dc.title","Coherent diffractive imaging beyond the projection approximation: waveguiding at extreme ultraviolet wavelengths"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","eaao4641"],["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","Science Advances"],["dc.bibliographiccitation.volume","3"],["dc.contributor.author","Kfir, Ofer"],["dc.contributor.author","Zayko, Sergey"],["dc.contributor.author","Nolte, Christina"],["dc.contributor.author","Sivis, Murat"],["dc.contributor.author","Möller, Marcel"],["dc.contributor.author","Hebler, Birgit"],["dc.contributor.author","Arekapudi, Sri Sai Phani Kanth"],["dc.contributor.author","Steil, Daniel"],["dc.contributor.author","Schäfer, Sascha"],["dc.contributor.author","Albrecht, Manfred"],["dc.contributor.author","Cohen, Oren"],["dc.contributor.author","Mathias, Stefan Dirk"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2019-11-28T10:23:22Z"],["dc.date.available","2019-11-28T10:23:22Z"],["dc.date.issued","2017"],["dc.description.abstract","This work demonstrates nanoscale magnetic imaging using bright circularly polarized high-harmonic radiation. We utilize the magneto-optical contrast of worm-like magnetic domains in a Co/Pd multilayer structure, obtaining quantitative amplitude and phase maps by lensless imaging. A diffraction-limited spatial resolution of 49 nm is achieved with iterative phase reconstruction enhanced by a holographic mask. Harnessing the exceptional coherence of high harmonics, this approach will facilitate quantitative, element-specific, and spatially resolved studies of ultrafast magnetization dynamics, advancing both fundamental and applied aspects of nanoscale magnetism."],["dc.identifier.doi","10.1126/sciadv.aao4641"],["dc.identifier.pmid","29250601"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62695"],["dc.language.iso","en"],["dc.relation.eissn","2375-2548"],["dc.relation.issn","2375-2548"],["dc.title","Nanoscale magnetic imaging using circularly polarized high-harmonic radiation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","JPhys Photonics"],["dc.bibliographiccitation.volume","2"],["dc.contributor.affiliation","Bordo, Eliyahu;"],["dc.contributor.affiliation","Kfir, Ofer;"],["dc.contributor.affiliation","Zayko, Sergey;"],["dc.contributor.affiliation","Neufeld, Ofer;"],["dc.contributor.affiliation","Fleischer, Avner;"],["dc.contributor.affiliation","Ropers, Claus;"],["dc.contributor.affiliation","Cohen, Oren;"],["dc.contributor.author","Bordo, Eliyahu"],["dc.contributor.author","Kfir, Ofer"],["dc.contributor.author","Neufeld, Ofer"],["dc.contributor.author","Fleischer, Avnerf"],["dc.contributor.author","Ropers, Claus"],["dc.contributor.author","Cohen, Oren"],["dc.contributor.author","Zayko, Sergey"],["dc.date.accessioned","2020-05-29T09:51:02Z"],["dc.date.available","2020-05-29T09:51:02Z"],["dc.date.issued","2020"],["dc.date.updated","2022-02-09T13:18:44Z"],["dc.description.abstract","AbstractThe ellipticity of high harmonics driven by bi-chromatic (e.g. ω−2ω) co-propagating fields can be fully tuned by varying the polarization of the pump components. In order to start revealing the underlying mechanism of this control, we explore a relatively simple regime of this scheme that still gives rise to full control over the harmonics ellipticities. In this regime, the pumps are only slightly elliptical and the high harmonic radiation consists of two (different) interlocked attosecond pulse trains (APTs). We formulate a semi-analytic model that maps the high harmonic ellipticity to properties of the APTs harmonic decompositions. Utilizing this model, we reconstruct these APTs variables from measurements of the high harmonics ellipticities. This ellipticity-resolved spectroscopy of interlocked APTs may be useful for ultrafast probing of chiral degrees of freedom."],["dc.identifier.doi","10.1088/2515-7647/ab8a5c"],["dc.identifier.eissn","2515-7647"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/66019"],["dc.language.iso","en"],["dc.publisher","IOP Publishing"],["dc.relation.issn","2515-7647"],["dc.rights.uri","http://creativecommons.org/licenses/by/4.0"],["dc.title","Interlocked attosecond pulse trains in slightly bi-elliptical high harmonic generation"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","15310"],["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","Optics Express"],["dc.bibliographiccitation.lastpage","15315"],["dc.bibliographiccitation.volume","23"],["dc.contributor.author","Mey, Tobias"],["dc.contributor.author","Zayko, Sergey"],["dc.contributor.author","Ropers, Claus"],["dc.contributor.author","Schaefer, Bernd"],["dc.contributor.author","Mann, Klaus"],["dc.date.accessioned","2018-11-07T09:55:51Z"],["dc.date.available","2018-11-07T09:55:51Z"],["dc.date.issued","2015"],["dc.description.abstract","The beam transport of single high-order harmonics in a monochromator arrangement is studied. A toroidal grating combines spectral filtering and focusing in order to produce a small individual spot for each harmonic. Here, the effect of small deviations from perfect alignment is investigated. Experimentally, a Hartmann sensor monitors the EUV wavefront while the grating is subjected to an online alignment procedure. The obtained results are confirmed by a simple theoretical description employing optical matrix methods. (C) 2015 Optical Society of America."],["dc.identifier.doi","10.1364/OE.23.015310"],["dc.identifier.isi","000356902500019"],["dc.identifier.pmid","26193511"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/36840"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1094-4087"],["dc.title","Toroidal grating astigmatism of high-harmonics characterized by EUV Hartmann sensor"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","6337"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Nature Communications"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Zayko, Sergey"],["dc.contributor.author","Kfir, Ofer"],["dc.contributor.author","Heigl, Michael"],["dc.contributor.author","Lohmann, Michael"],["dc.contributor.author","Sivis, Murat"],["dc.contributor.author","Albrecht, Manfred"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2021-12-01T09:20:51Z"],["dc.date.available","2021-12-01T09:20:51Z"],["dc.date.issued","2021"],["dc.description.abstract","Light-induced magnetization changes, such as all-optical switching, skyrmion nucleation, and intersite spin transfer, unfold on temporal and spatial scales down to femtoseconds and nanometers, respectively. Pump-probe spectroscopy and diffraction studies indicate that spatio-temporal dynamics may drastically affect the non-equilibrium magnetic evolution. Yet, direct real-space magnetic imaging on the relevant timescales has remained challenging. Here, we demonstrate ultrafast high-harmonic nanoscopy employing circularly polarized high-harmonic radiation for real-space imaging of femtosecond magnetization dynamics. We map quenched magnetic domains and localized spin structures in Co/Pd multilayers with a sub-wavelength spatial resolution down to 16 nm, and strobosocopically trace the local magnetization dynamics with 40 fs temporal resolution. Our compact experimental setup demonstrates the highest spatio-temporal resolution of magneto-optical imaging to date. Facilitating ultrafast imaging with high sensitivity to chiral and linear dichroism, we envisage a wide range of applications spanning magnetism, phase transitions, and carrier dynamics."],["dc.description.sponsorship","Open-Access-Publikationsfonds 2022"],["dc.identifier.doi","10.1038/s41467-021-26594-0"],["dc.identifier.pii","26594"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/94287"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-478"],["dc.relation.eissn","2041-1723"],["dc.rights","CC BY 4.0"],["dc.title","Ultrafast high-harmonic nanoscopy of magnetization dynamics"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]