Professor John Rodenburg
FRS, PhD, BSc
Department of Electronic and Electrical Engineering
Professor of Computational Microscopy
Former Faculty Director of Ion and Electron Microscopy
Imaging: Ptychography Lensless X-ray Electron Light Research Group
Semiconductor Materials and Devices Research Group
Full contact details
Department of Electronic and Electrical Engineering
I studied Physics as an undergraduate at the University of Exeter and then did my PhD in the Cavendish Laboratory, University of Cambridge, where later I held a Royal Society University Research Fellowship.
I was also a Fellow of Murry Edwards College (formerly New Hall), where I taught physics and mathematics.
After a brief excursion from academic life to set up my first company, I moved to Sheffield Hallam University to take up the Chair of Materials Analysis in the Materials and Engineering Research Institute (MERI). I moved to the EEE Department in University of Sheffield in 2003.
My research career started with instrument development to record coherent electron diffraction patterns. Results from this led me to have an idea about how to improve transmission microscopes for atomic imaging by using an inverse computational method, now referred to as ‘ptychography’.
My original formulation of ptychography proved to be rather harder to do experimentally than I expected, and so I gave up on it at the end of the 1990s. However, I returned to it afresh in the 2000s, developing a completely new iterative solution to the phase problem.
Ptychography has since become a standard technique in X-ray microscopy, and has made substantial impact in EUV, electron and visible-light microscopy.
I continue to develop various forms of it. I set up a second company (Phase Focus Ltd) in 2006, working for it part time as Chief Scientific Officer until 2015.
- Fellow of the Royal Society
- Chartered Physicist
- PhD in Physics (University of Cambridge)
- BSc in Physics with Electronics (University of Exeter)
- Research interests
- The theory and modelling of inverse computational imaging strategies
- Diffractive imaging, specifically ptychography
- Experimental X-ray, electron and visible-light ptychography
- Electron microscopy and associated spectroscopies
- Development of experimental configurations in X-ray microscopy
- Instrument and detector development in electron microscopy
- Applications of electron microscopy to materials science
- An X-ray ptycho-tomography model of ‘Seeing order in “amorphous” materials’. Ultramicroscopy. View this article in WRRO
- Diffraction-limited superresolution ptychography in the Rayleigh–Sommerfeld regime. Journal of the Optical Society of America A, 36(2), A12-A19. View this article in WRRO
- A record-breaking microscope. Nature, 559(7714), 334-335. View this article in WRRO
- Image feature delocalization in defocused probe electron ptychography. Ultramicroscopy, 187, 71-83. View this article in WRRO
- Modal decomposition of a propagating matter wave via electron ptychography. Physical Review A, 94. View this article in WRRO
- Breaking ambiguities in mixed state ptychography. Optics Express, 24(8), 9038-9038. View this article in WRRO
- Multiple mode x-ray ptychography using a lens and a fixed diffuser optic. Journal of Optics, 18(5).
- Separation of three-dimensional scattering effects in tilt-series Fourier ptychography. Ultramicroscopy, 158, 1-7.
- Pixel size adjustment in coherent diffractive imaging within the Rayleigh–Sommerfeld regime. Applied Optics, 54(8), 1936-1936.
- Possibility of high-resolution ptychographic iterative imaging with low energy electrons: dynamical calculations. Microscopy, 64(2), 105-110.
- Ptychographic inversion via Wigner distribution deconvolution: Noise suppression and probe design. Ultramicroscopy, 147, 106-113.
- Ptychographic microscope for three-dimensional imaging. Optics Express, 22(10), 12513-12523.
- Reciprocal-space up-sampling from real-space over sampling in x-ray ptychography. PHYSICAL REVIEW A, 89(4).
- Coherent x-ray imaging of collagen fibril distributions within intact tendons.. Biophys J, 106(2), 459-466.
- Multiwavelength Ptychography, 689-694.
- Information multiplexing in ptychography.. Ultramicroscopy, 138, 13-21.
- Translation position determination in ptychographic coherent diffraction imaging.. Opt Express, 21(11), 13592-13606.
- Sampling in x-ray ptychography. Physical Review A - Atomic, Molecular, and Optical Physics, 87(5).
- Soft X-ray spectromicroscopy using ptychography with randomly phased illumination.. Nat Commun, 4, 1669.
- Dual wavelength optical metrology using ptychography. Journal of Optics (United Kingdom), 15(3).
- Coherence requirement in digital holography.. Appl Opt, 52(1), A326-A335.
- Noise models for low counting rate coherent diffraction imaging. Optics Express, 20(23), 25914-25914.
- An annealing algorithm to correct positioning errors in ptychography.. Ultramicroscopy, 120, 64-72.
- Quantitative phase contrast optimised cancerous cell differentiation via ptychography.. Opt Express, 20(9), 9911-9918.
- Ptychographic electron microscopy using high-angle dark-field scattering for sub-nanometre resolution imaging.. Nat Commun, 3, 730. View this article in WRRO
- Electron Ptychography: Applications Of The Electron Wave Phase. Microscopy and Microanalysis, 18(S2), 502-503.
- Atomic resolution transmission imaging at 30keV via electron ptychography. Microscopy and Microanalysis, 18(S2), 1024-1025.
- Ptychographic transmission microscopy in three dimensions using a multi-slice approach. Journal of the Optical Society of America A: Optics and Image Science, and Vision, 29(8), 1606-1614.
- Ptychography: a powerful phase retrieval technique for biomedical imaging. Tenth International Conference on Correlation Optics.
- Coherent x-ray diffraction imaging of paint pigment particles by scanning a phase plate modulator. NEW JOURNAL OF PHYSICS, 13.
- Transmission Diffractive Microscopy Without Lenses at Visible, X-ray and Electron Wavelengths. Microscopy and Microanalysis, 17(S2), 1058-1059.
- Evolutionary determination of experimental parameters for ptychographical imaging. J APPL PHYS, 109(12).
- Superresolution imaging via ptychography.. J Opt Soc Am A Opt Image Sci Vis, 28(4), 604-612.
- Extended ptychography in the transmission electron microscope: possibilities and limitations.. Ultramicroscopy, 111(8), 1117-1123.
- Analysis and interpretation of the Seidel aberration coefficients in digital holography. Applied Optics, 50(34), H220-H220.
- Ptychography: A novel phase retrieval technique, advantages and its application. Proceedings of SPIE - The International Society for Optical Engineering, 8001.
- Wave-front phase retrieval in transmission electron microscopy via ptychography. PHYS REV B, 82(12).
- Phase retrieval based on wave-front relay and modulation. PHYS REV B, 82(12).
- Optical ptychography: a practical implementation with useful resolution.. Opt Lett, 35(15), 2585-2587.
- Quantitative Phase Retrieval by Ptychography in TEM. Microscopy and Microanalysis, 16(S2), 748-749.
- The role of helium ion microscopy in the characterisation of complex three-dimensional nanostructures.. Ultramicroscopy, 110(9), 1178-1184.
- Wavefront modulation coherent diffractive imaging. AIP Conference Proceedings, 1365, 223-226.
- Probe position recovery for ptychographical imaging. Journal of Physics: Conference Series, 241.
- Noise limit on practical electron ptychography. Journal of Physics: Conference Series, 241.
- Solving for the phase of STEM probes in real space. Journal of Physics: Conference Series, 241.
- High resolution transmission imaging without lenses. Journal of Physics: Conference Series, 241.
- Resolution improvement in coherent diffractive imaging (ptychography). Proceedings of SPIE - The International Society for Optical Engineering, 7729.
- A new method of high resolution, quantitative phase scanning microscopy. Proceedings of SPIE - The International Society for Optical Engineering, 7729.
- An improved ptychographical phase retrieval algorithm for diffractive imaging.. Ultramicroscopy, 109(10), 1256-1262.
- Influence of thick crystal effects on ptychographic image reconstruction with moveable illumination.. Ultramicroscopy, 109(10), 1263-1275.
- A comprehensive Monte Carlo calculation of dopant contrast in secondary-electron imaging. EPL-EUROPHYS LETT, 82(3).
- Dynamical and geometric effects in ptychographic diffractive imaging. Journal of Physics: Conference Series, 126.
- An optical demonstration of ptychographical imaging for focussed-probe illumination. Journal of Physics: Conference Series, 126.
- Ptychography and related diffractive imaging methods. ADV IMAG ELECT PHYS, 150, 87-184.
- Transmission microscopy without lenses for objects of unlimited size.. Ultramicroscopy, 107(2-3), 227-231.
- Hard-x-ray lensless imaging of extended objects.. Phys Rev Lett, 98(3), 034801.
- Error tolerance of an iterative phase retrieval algorithm for moveable illumination microscopy.. Ultramicroscopy, 103(2), 153-164.
- A phase retrieval algorithm for shifting illumination. APPL PHYS LETT, 85(20), 4795-4797.
- Movable aperture lensless transmission microscopy: a novel phase retrieval algorithm.. Phys Rev Lett, 93(2), 023903.
- Internal structure of TiAlN/VN coating deposited on sharp edges by ion-assisted physical vapor deposition. J VAC SCI TECHNOL A, 22(4), 1195-1199.
- Synthesis of nanosize powders and thin films of Yb-doped YAG by sol-gel methods. CHEM MATER, 15(18), 3474-3480.
- Plasma-surface interaction at sharp edges and corners during ion-assisted physical vapor deposition. Part I: Edge-related effects and their influence on coating morphology and composition. J APPL PHYS, 94(5), 2829-2836.
- Plasma-surface interaction at sharp edges and corners during ion-assisted physical vapor deposition. Part II: Enhancement of the edge-related effects at sharp corners. J APPL PHYS, 94(5), 2837-2844.
- Edge related effects during ion assisted PVD on sharp edges and implications for coating of cutting tools. SURF ENG, 19(4), 310-314.
- Manufacturing of YbAG coatings and crystallisation of the pure and Li2O-doped Yb2O3-A1(2)O(3) system by a modified sol-gel method. MATER CHEM PHYS, 77(3), 802-807.
- A simple model of holography and some enhanced resolution methods in electron microscopy.. Ultramicroscopy, 87(3), 105-121.
- Crystal orientation effects on sputtering and depth resolution in GDOES. SURF INTERFACE ANAL, 31(3), 206-211.
- Physics, economics and Hollywood. Physics World, 12(2), 60-60.
- Electron ptychography. I. Experimental demonstration beyond the conventional resolution limits. ACTA CRYSTALLOGR A, 54, 49-60.
- Electron ptychography. II. Theory of three-dimensional propagation effects. ACTA CRYSTALLOGR A, 54, 61-73.
- Complex image reconstruction of weak specimens from a three-sector detector in the STEM (vol 101, pg 53, 1995). OPTIK, 103(3), 131-132.
- Complex image reconstruction of weak specimens from a three-sector detector in the STEM: Correction. Optik (Jena), 103(3), 131-132.
- DOUBLE RESOLUTION IMAGING OF WEAK PHASE SPECIMENS WITH QUADRANT DETECTORS IN THE STEM. OPTIK, 100(1), 37-46.
- RESOLUTION BEYOND THE INFORMATION LIMIT IN TRANSMISSION ELECTRON-MICROSCOPY. NATURE, 374(6523), 630-632.
- BEYOND THE CONVENTIONAL INFORMATION LIMIT - THE RELEVANT COHERENCE FUNCTION. ULTRAMICROSCOPY, 54(1), 61-74.
- DOUBLE RESOLUTION IMAGING WITH INFINITE DEPTH OF FOCUS IN SINGLE LENS SCANNING MICROSCOPY. OPTIK, 96(1), 31-36.
- ERROR ANALYSIS OF CRYSTALLINE PTYCHOGRAPHY IN THE STEM MODE. ULTRAMICROSCOPY, 52(1), 85-99.
- EXPERIMENTAL TESTS ON DOUBLE-RESOLUTION COHERENT IMAGING VIA STEM. ULTRAMICROSCOPY, 48(3), 304-314.
- MICROSCOPY IN SOLID-STATE SCIENCE. MICROSC RES TECHNIQ, 24(4), 299-315.
- SIMULTANEOUS RECONSTRUCTION OF OBJECT AND APERTURE FUNCTIONS FROM MULTIPLE FAR-FIELD INTENSITY MEASUREMENTS. J OPT SOC AM A, 10(2), 231-239.
- 2-DIMENSIONAL DEMONSTRATION OF WIGNER PHASE-RETRIEVAL MICROSCOPY IN THE STEM CONFIGURATION. ULTRAMICROSCOPY, 45(3-4), 371-380.
- THE THEORY OF SUPERRESOLUTION ELECTRON-MICROSCOPY VIA WIGNER-DISTRIBUTION DECONVOLUTION. PHILOS T ROY SOC A, 339(1655), 521-553.
- OPTICAL DEMONSTRATION OF A NEW PRINCIPLE OF FAR-FIELD MICROSCOPY. J PHYS D APPL PHYS, 25(2), 147-154.
- A new look at the resolution limit. Micron And Microscopica Acta, 23(1-2), 213-214.
- PARALLEL EELS CCD DETECTOR FOR A VG HB501 STEM. INST PHYS CONF SER(98), 55-58.
- SUB-ANGSTROM TRANSMISSION MICROSCOPY - A FOURIER-TRANSFORM ALGORITHM FOR MICRODIFFRACTION PLANE INTENSITY INFORMATION. ULTRAMICROSCOPY, 31(3), 303-308.
- THE PHASE PROBLEM, MICRODIFFRACTION AND WAVELENGTH-LIMITED RESOLUTION - A DISCUSSION. ULTRAMICROSCOPY, 27(4), 413-422.
- PROPERTIES OF ELECTRON MICRODIFFRACTION PATTERNS FROM AMORPHOUS MATERIALS. ULTRAMICROSCOPY, 25(4), 329-343.
- INTENSITY CORRELATIONS IN MICRODIFFRACTION FROM AMORPHOUS MATERIALS. J PHYS-PARIS, 46(C-9), 59-62.
- MEASUREMENT OF AN ATOMIC POSITION COHERENCE LENGTH IN A-GE. J PHYS-PARIS, 46(C-9), 63-68.
- THE RECORDING OF MICRODIFFRACTION PATTERNS IN SCANNING-TRANSMISSION ELECTRON-MICROSCOPY. J PHYS E SCI INSTRUM, 18(11), 949-953.
- A HIGH-RESOLUTION MICRODIFFRACTION CAMERA FOR STEM. INST PHYS CONF SER(68), 511-514.
- Ptychography, Springer Handbook of Microscopy (pp. 819-904). Springer International Publishing View this article in WRRO
- Defocus and probe-position coupling in electron ptychography (pp. 475-476). Wiley-VCH Verlag GmbH & Co. KGaA
- An optical demonstration of ptychographical imaging of a single defect in a model crystal, EMC 2008 14th European Microscopy Congress 1–5 September 2008, Aachen, Germany (pp. 701-702). Springer Berlin Heidelberg
Conference proceedings papers
- OPTICAL ARRANGEMENTS FOR PHASE-SENSITIVE IMAGING USING ELECTRON PTYCHOGRAPHY. RECENT TRENDS IN CHARGED PARTICLE OPTICS AND SURFACE PHYSICS INSTRUMENTATION (pp 60-61)
- Ptychography: lensless high-resolution phase-sensitive imaging. Classical Optics 2014, 2014.
- Comparison of different digital holographic setup configurations. Biomedical Optics and 3-D Imaging, 2012.
- Ptychography - early history and 3D scattering effects. SHORT-WAVELENGTH IMAGING AND SPECTROSCOPY SOURCES, Vol. 8678
- Ptychography applied to optical metrology. SPECKLE 2012: V INTERNATIONAL CONFERENCE ON SPECKLE METROLOGY, Vol. 8413
- TRANSMISSION AND REFLECTION MICROSCOPY WITHOUT LENSES. RECENT TRENDS IN CHARGED PARTICLE OPTICS AND SURFACE PHYSICS INSTRUMENTATION (pp 61-62)
- Measuring coherence in an electron beam for imaging. EMC2008- 14th European Microscopy Congress, Vol. 1 (Instrumentation and Methods) (pp 165-166). Berlin, 1 September 2008 - 5 September 2008.
- Investigating the influence of dynamic scattering on ptychographical iterative techniques. EMC2008- 14th European Microscopy Congress, Vol. 1 (Instrumentation and Methods) (pp 723-724). Berlin, 1 September 2008 - 5 September 2008.
- STEM probe characteristics at large defoci for use in ptychographical imaging. - art. no. 012092. EMAG: ELECTRON MICROSCOPY AND ANALYSIS GROUP CONFERENCE 2007, Vol. 126 (pp 12092-12092)
- A technique for real-time, in situ SEM observation of grain growth at elevated temperatures. RECRYSTALLIZATION AND GRAIN GROWTH, PTS 1 AND 2, Vol. 467-470 (pp 1385-1388)
- Electrochemical and AFM/SEM studies of Ni-Cr electroplated and sol-gel coated samples. ELECTRON MICROSCOPY AND ANALYSIS 2003(179) (pp 417-420)
- Backscattered SEM imaging of high-temperature samples for grain growth studies in metals. ELECTRON MICROSCOPY AND ANALYSIS 2003(179) (pp 181-184)
- Can Ronchigrams provide a route to sub-angstrom tomographic reconstruction?. ELECTRON MICROSCOPY AND ANALYSIS 2003(179) (pp 185-190)
- Investigation of intermixing in TiAlN/VN nanoscale multilayer coatings by energy-filtered TEM. SURFACE & COATINGS TECHNOLOGY, Vol. 151 (pp 209-213)
- Electron microscopy studies of hard coatings deposited on sharp edges by combined cathodic arc/unbalanced magnetron PVD. SURFACE & COATINGS TECHNOLOGY, Vol. 151 (pp 349-354)
- Time- and space-dependent image contrast mechanisms in environmental scanning electron microscopy (ESEM). ELECTRON MICROSCOPY AND ANALYSIS 2001(168) (pp 73-76)
- Quantitative EDX-analysis of PVD hard coatings deposited on sharp edges. ELECTRON MICROSCOPY AND ANALYSIS 2001(168) (pp 345-348)
- Measurement of higher-order correlation functions in amorphous materials via coherent microdiffraction. ELECTRON MICROSCOPY AND ANALYSIS 1999(161) (pp 145-148)
- Measuring lens parameters from coherent Ronchigrams in STEM. ELECTRON MICROSCOPY AND ANALYSIS 1999(161) (pp 339-342)
- A method for measuring the effective source coherence in a field emission transmission electron microscope. APPLIED SURFACE SCIENCE, Vol. 111 (pp 174-179)
- A novel ultra-sharp field emission electron source demonstrated in a STEM. ELECTRON MICROSCOPY AND ANALYSIS 1997(153) (pp 65-68)
- Super-resolution STEM imaging of crystals with large unit cells. ELECTRON MICROSCOPY AND ANALYSIS 1997(153) (pp 117-120)
- Measurement and improvement of the effective source coherence in STEM. ELECTRON MICROSCOPY AND ANALYSIS 1995, Vol. 147 (pp 277-280)
- Experimental tests of double-resolution imaging with quadrant detectors in the STEM. ELECTRON MICROSCOPY AND ANALYSIS 1995, Vol. 147 (pp 281-284)
- Super-resolution STEM imaging in the presence of specimen drift. ELECTRON MICROSCOPY AND ANALYSIS 1995, Vol. 147 (pp 107-110)
- Ptychographical imaging of sphalerite structures. ELECTRON MICROSCOPY AND ANALYSIS 1995, Vol. 147 (pp 117-120)
- Direct measurement of the effective source coherence in STEM. ELECTRON MICROSCOPY 1994, VOL 1 (pp 209-210)
- STEM imaging of <110> tetrahedral semiconductors. ELECTRON MICROSCOPY 1994, VOL 1 (pp 489-490)
- Simulations on super-resolution imaging of perfect crystals. ELECTRON MICROSCOPY 1994, VOL 1 (pp 939-940)
- Double-resolution imaging with quadrant detectors in STEM. ELECTRON MICROSCOPY 1994, VOL 1 (pp 155-156)
- DECONVOLVING LENS TRANSFER-FUNCTIONS IN ELECTRON HOLOGRAMS. ULTRAMICROSCOPY, Vol. 52(3-4) (pp 248-252)
- IMAGE-RESOLUTION IMPROVEMENT USING COHERENT MICRODIFFRACTION IN STEM. ELECTRON MICROSCOPY AND ANALYSIS 1993(138) (pp 239-242)
- THICKNESS LIMITATIONS OF ABERRATION-FREE PROJECTION IMAGING. ELECTRON MICROSCOPY AND ANALYSIS 1993(138) (pp 243-246)
- DIRECT COMPLEX TRANSFER-FUNCTION RECONSTRUCTION BY PROCESSING OF NEAR-FOCUS SHADOW IMAGES IN STEM. ELECTRON MICROSCOPY AND ANALYSIS 1993(138) (pp 251-254)
- INFORMATION IN RONCHIGRAMS OF A SUPERLATTICE FROM DEFOCUSED MICRODIFFRACTION IN STEM. ELECTRON MICROSCOPY AND ANALYSIS 1993(138) (pp 167-170)
- MICRODIFFRACTION MEASUREMENTS OF STRAIN IN A STEM. ELECTRON MICROSCOPY AND ANALYSIS 1991, Vol. 119 (pp 409-412)
- PHASE RECONSTRUCTION IMAGING IN SCANNING-TRANSMISSION MICROSCOPY VIA THE MICRODIFFRACTION PLANE. ELECTRON MICROSCOPY AND ANALYSIS 1991, Vol. 119 (pp 491-494)
- APERTURE FRINGE EFFECTS IN COHERENT CBED PATTERNS. ELECTRON MICROSCOPY AND ANALYSIS 1991, Vol. 119 (pp 395-396)
- A CROSS-CORRELATION MEASURE OF ORDER IN AMORPHOUS INDIUM OXIDE. EMAG-MICRO 89, VOLS 1 AND 2, Vol. 98 (pp 119-122)
- HIGH-RESOLUTION TIME RESOLVED EELS AND CACO3. TRANSACTIONS OF THE ROYAL MICROSCOPICAL SOCIETY : NEW SERIES, VOL 1, Vol. 1 (pp 185-188)
- HIGHER SPATIAL-RESOLUTION VIA SIGNAL-PROCESSING OF THE MICRODIFFRACTION PLANE. EMAG-MICRO 89, VOLS 1 AND 2, Vol. 98 (pp 103-106)
- MICRODIFFRACTION. EUREM 88, VOLS 1-3, Vol. 93 (pp 3-8)
Dates Sponsor Grant Title PI/co-I Sept 11 - Feb 17 EPSRC Phase modulation technology for X-ray imaging Co-I
- Teaching activities
- EEE6226, Future trends in Electronic and Electrical Engineering
- Professional activities and memberships
- Faculty Director of Ion and Electron Microscopy
- Research students
Student Degree Status Primary/Secondary Atkinson K M PhD Graduated Primary Batey D PhD Graduated Primary Cao S PhD Graduated Primary Edo T B PhD Graduated Primary Li P PhD Graduated Primary