Research
Our current research topics include: method development of novel coherent high-resolution 3D imaging techniques - holography and coherent diffraction imaging; algorithms for wavefront propagation, simulation and reconstruction of holograms and diffraction patterns, iterative phase retrieval algorithms; convergent beam electron diffraction, 2D materials, coherent imaging with low-energy electrons (20 - 300 eV), wavefront modulation.
Team
Alice Kohli
Master student (2021 - 2022)
Sarah Bernardinis
Bachelor student (2022)
Open Positions
Students of the University of Zurich are welcome to contact us for Bachelor and Master projects.
Teaching
Publications
2024
- A new family of septuple-layer 2D materials of MoSi2N4-like crystalsNature Reviews Physics (2024).
- Double-slit holography—a single-shot lensless imaging techniqueScientific Reports 14, 12528 (2024).
- Criteria for objects suitable for reconstruction from holograms and diffraction patternsJournal of the Optical Society of America A 41(11), 2219-2230 (2024).
2023
- Controlling topological states in bilayer grapheneNature Nanotechnology (2023).
- Fourier Transform Holography: A Lensless Imaging Technique, Its Principles and ApplicationsPhotonics 10(2), 153 (2023).
- Coherent imaging with low-energy electrons, quantitative analysisUltramicroscopy 253, 113807 (2023).
- Potentials of individual atoms by convergent beam electron diffractionCarbon 201, 244-250 (2023).
2022
- Low-dose shift- and rotation-invariant diffraction recognition imagingScientific Reports 12, 11202 (2022).
- Imaging defects in two-dimensional crystals by convergent-beam electron diffractionPhysical Review B 105, 184113 (2022).
2021
- Bragg holography of nano-crystalsUltramicroscopy 230, 113376 (2021).
- Three-dimensional structure from single two-dimensional diffraction intensity measurementPhysical Review Letters 127(6), 063601 (2021).
- Holographic convergent electron beam diffraction (CBED) imaging of two-dimensional crystalsSurface Review and Letters 28(8), 2140001 (2021).
- Phase retrieval methods applied to coherent imagingAdvances in Imaging and Electron Physics 218, 1 (2021).
- Symmetry of diffraction patterns of two-dimensional crystal structuresUltramicroscopy 228, 113336 (2021).
- Wavefront modulation and beam shaping into arbitrary three-dimensional intensity distributionsPhotonics 8(6), 179 (2021).
- Three-dimensional volumetric deconvolution in coherent optics and holographyApplied Optics 60(5), 1304 (2021).DOI: 10.1364/AO.412736
2020
- Holographic reconstruction of the interlayer distance of bilayer two-dimensional crystal samples from their convergent beam electron diffraction patternsUltramicroscopy 219, 113020 (2020).
- Holography and Coherent Diffraction Imaging with Low-(30–250 eV) and High-(80–300 keV) Energy Electrons: History, Principles, and Recent TrendsMaterials 13, 3089 (2020).DOI: 10.3390/ma13143089 "Congrats on your excellent review in Materials!" by John Spence
- Convergent beam electron diffraction of multilayer van der Waals structuresUltramicroscopy 212, 112976 (2020).
2019
- Iterative phase retrieval for digital holography (invited)Journal of the Optical Society of America 36, D31 (2019).
- Reconstruction of missing information in diffraction patterns and holograms by iterative phase retrievalOptics Communications 452, 56 (2019).
- Inelastic scattering and solvent scattering reduce dynamical diffraction in biological crystalsActa Crystallographica Section B 75, 52 (2019).
- Direct visualization of charge transport in suspended (or free-standing) DNA strands by low-energy electron microscopyScientific Reports 9, 8889 (2019).
- Lateral and axial resolution criteria in incoherent and coherent optics and holography, near- and far-field regimesApplied Optics 58, 3597 (2019).DOI: 10.1364/AO.58.003597
- Ultrafast holography enabled by quantum interference of ultrashort electronsScience Advances 5, eaav8358 (2019).
- Local photo-mechanical stiffness revealed in gold nanoparticles supracrystals by ultrafast small-angle electron diffractionStructural Dynamics 6, 024304 (2019).DOI: 10.1063/1.5091858
- Moiré structures in twisted bilayer graphene studied by transmission electron microscopyUltramicroscopy 197, 46 (2019).
- Stacking transition in rhombohedral graphiteFrontiers of Physics 14, 13608 (2019).
- Convergent and divergent beam electron holography and reconstruction of adsorbates on free-standing two-dimensional crystalsFrontiers of Physics 14, 13606 (2019).
2018
- Investigating Skyrmions Using Lorentz Transmission Electron MicroscopyMicroscopy and Microanalysis 24, 932 (2018).
- Three-dimensional double helical DNA structure directly revealed from its X-ray fiber diffraction pattern by iterative phase retrievalOptics Express 26, 30991 (2018).DOI: 10.1364/OE.26.030991
- Iterative phase retrieval in coherent diffractive imaging: practical issuesApplied Optics 57, 7187 (2018).DOI: 10.1364/AO.57.007187
- Algorithms and image formation in orbital tomographyPhysical Review B 98, 085426 (2018).
- Convergent beam electron holography for analysis of van der Waals heterostructuresPNAS 115, 7473 (2018).
- Metal adsorption and nucleation on free-standing graphene by low-energy electron point source microscopyNano Letters 18, 3421 (2018).
2017
- Resolution enhancement in in-line holography by numerical compensation of vibrationsOptics Express 25, 20109 (2017).DOI: 10.1364/OE.25.020109
- Imaging the potential distribution of charged adsorbates on graphene by low-energy electron holographyUltramicroscopy 182, 276 (2017).
- Three-dimensional surface topography of graphene by divergent beam electron diffractionNature Communications 8, 14440 (2017).DOI: 10.1038/ncomms14440
- Spatial coherence of electron beams from field emitters and its effect on the resolution of imaged objectsUltramicroscopy 175, 121 (2017).
- Imaging proteins at the single-molecule levelPNAS 114, 1474 (2017).
2016
- Application of iterative phase-retrieval algorithms to ARPES orbital tomographyNew Journal of Physics 18, 093041 (2016).
- Resolution enhancement by extrapolation of coherent diffraction images: a quantitative study about the limits and a numerical study of non-binary and phase objectsJournal of Microscopy 264, 2 (2016).DOI: 10.1111/jmi.12408
- Direct observation of individual charges and their dynamics on graphene by low-energy electron holographyNano Letters 16, 5469 (2016).
- Mapping unoccupied electronic states of freestanding graphene by angle-resolved low-energy electron transmissionPhysical Review B 94, 075424 (2016).
- Creating Airy beams employing a transmissive spatial light modulatorApplied Optics 55, 6095 (2016).DOI: 10.1364/AO.55.006095
- Inverted Gabor holography principle for tailoring arbitrary shaped three-dimensional beamsScientific Reports 6, 26312 (2016).DOI: 10.1038/srep26312
- Order/disorder dynamics in a dodecanethiol-capped gold nanoparticles supracrystal by small-angle ultrafast electron diffractionNano Letters 16, 2705 (2016).
- Invariant time-dependent exchange perturbation theory and its application to the particles collision problemHighlights in Theoretical Chemistry 11, 41 (2016).
2015
- Imaging outside the box: Resolution enhancement in X-ray coherent diffraction imaging by extrapolation of diffraction patternsApplied Physics Letters 107, 183102 (2015).DOI: 10.1063/1.4934879
- Filming the formation and fluctuation of skyrmion domains by cryo-Lorentz transmission electron microscopyPNAS112, 14212 (2015).
- The role of the coherence in the cross-correlation analysis of diffraction patterns from two-dimensional dense mono-disperse systemsScientific Report 5, 16573 (2015).DOI: 10.1038/srep16573
- Holography and coherent diffraction with low-energy electrons: A route towards structural biology at the single molecule levelUltramicroscopy 159, 395 (2015).
- Terahertz in-line digital holography of human hepatocellular carcinoma tissueScientific Reports 5, 8445 (2015).DOI: 10.1038/srep08445
- Low-energy electron holographic imaging of individual tobacco mosaic virionsApplied Physics Letters 107, 133101 (2015).DOI: 10.1063/1.4931607
- Invariant time-dependent exchange perturbation theory and its application to the particles collision problemTheoretical Chemistry Accounts 134, 1 (2015).
- Atomically resolved structural determination of graphene and its point defects via extrapolation assisted phase retrievalApplied Physics Letters 106, 021908 (2015).DOI: 10.1063/1.4906089
- Practical algorithms for simulation and reconstruction of digital in-line hologramsApplied Optics 54, 2424 (2015).DOI: 10.1364/AO.54.002424
- Reconstruction of purely absorbing, absorbing and phase-shifting, and strong phase-shifting objects from their single-shot in-line hologramsApplied Optics 54, 3932 (2015).DOI: 10.1364/AO.54.003925
2014
- Holographic time-resolved particle tracking by means of three-dimensional volumetric deconvolutionOptics Express 22, 20994 (2014).DOI: 10.1364/OE.22.020994
- On artefact-free reconstruction of low-energy (30-250 eV) electron hologramsUltramicroscopy 145, 22 (2014).
- Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolationOptics Express 22, 17236 (2014).DOI: 10.1364/OE.22.017236
- Low-energy electron holographic imaging of ultraclean graphene-supported gold-nanorodsUltramicroscopy 145, 80 (2014).
2013
- Pulsed electron holographyApplied Physics Letters 102, 203115 (2013).DOI: 10.1063/1.4807661
- Coherent diffraction and holographic imaging of individual biomolecules using low-energy electronsAdvancing Methods for Biomolecular Crystallography. NATO Science for Peace and Security Series A: Chemistry and Biology ~, 331 (2013).
- Resolution enhancement in digital holography by self-extrapolation of hologramsOptics Express 21, 7726 (2013).DOI: 10.1364/OE.21.007726
- Graphene unit cell imaging by holographic coherent diffractionPhysical Review Letters 110, 255501 (2013).
- Coherent microscopy at resolution beyond diffraction limit using post-experimental data extrapolationApplied Physics Letters 103, 204105 (2013).DOI: 10.1063/1.4831985
2012
- When holography meets coherent diffraction imagingOptics Express 20, 28871 (2012).DOI: 10.1364/OE.20.028871
- Non-destructive imaging of an individual proteinApplied Physics Letters 101, 093701 (2012).DOI: 10.1063/1.4748113
- Low-energy electron transmission imaging of clusters on free-standing grapheneApplied Physics Letters 101, 113117 (2012).DOI: 10.1063/1.4752717
2011
- Novel Fourier-domain constraint for fast phase retrieval in coherent diffraction imagingOptics Express 19, 19330 (2011).DOI: 10.1364/OE.19.019330
- Individual filamentous phage imaged by electron holographyEurropean Biophysics Journal 40, 1197 (2011).
2010
- Nondestructive imaging of individual biomoleculesPhysical Review Letters 104, 095501 (2010).
- Off-axis and inline electron holography: Experimental comparisonUltramicroscopy 110, 472 (2010).
- Depth-resolved holographic reconstructions by three-dimensional deconvolutionOptics Express 18, 22527 (2010).DOI: 10.1364/OE.18.022527
- Graphene as a transparent conductive support for studying biological molecules by transmission electron microscopyApplied Physics Letters 97, 153102 (2010).DOI: 10.1063/1.3492845
2009
- Simultaneous reconstruction of phase and amplitude contrast from a single holographic recordOptics Express 17, 10697 (2009).DOI: 10.1364/OE.17.010697
2007
- Solution to the twin image problem in holographyPhysical Review Letters 98, 233901 (2007).
2006
- Resorcin[4]arene cavitand-based molecular switchesAdvanced Functional Materials 16, 147 (2006).
- Direct evidence for conduction pathways in a solid electrolytePhysical Review Letters 97, 136601 (2006).
- A single-molecule study of polycrystalline microstructure by fluorescence polarization spectroscopyJournal of Luminescence 118, 111 (2006).
- A quantum mechanical scheme to reduce radiation damage in electron microscopyApplied Physics Letters 88, 164103 (2006).DOI: 10.1063/1.2191096
- Axisymmetric liquid hanging dropsJournal of Chemical Education 83, 117 (2006).DOI: 10.1021/ed083p117
2003
- Single molecule spectroscopyJournal of the Chinese Chemical Society 50, 477 (2003).
2002
- Theory of the Stark effect on single molecular spectroscopyJournal of the Chinese Chemical Society 49, 797 (2002).
- Higher-order Stark effect on single-moleculesChemical Physics 282, 109 (2002).
2000
- Radio-frequency Stark effect modulation of single-molecule linesJournal of Luminescence 86, 189 (2000).
1999
- Detection and spectroscopy of single molecules in rare gas matrices: dibenzanthanthrene in krypton and xenonChemical Physics Letters 311, 29 (1999).
- Imaging and spectroscopy of terrylene molecules isolated in vapor-deposited n-alkane matricesChemical Physics 247, 35 (1999).
- Absorption spectroscopy on single molecules in solidsJournal of Chemical Physics 111, 8755 (1999).DOI: 10.1063/1.480222
- Advanced holographic nondestructive testing system for residual stress analysisProceedings of SPIE 3678, 73 (1999).DOI: 10.1117/12.347399
1998
- Recording and reconstruction of reflection and transmission holograms with a cw laser diodeSPIE Proceedings 3293, 131 (1999).DOI: 10.1117/12.303646
- Pulse recording of slanted fringe holograms in DuPont photopolymerSPIE Proceedings 3294, 132 (1999).DOI: 10.1117/12.304533
- The method of exchange perturbation theory as applied to magnetic ordering in high-Tc materialsJournal of Experimental and Theoretical Physics 86, 2129 (1999).DOI: 10.1134/1.558587