Dr Andrew Maiden
Department of Electronic and Electrical Engineering
Director of Programme Delivery
Senior Lecturer Computational Holography
Semiconductor Materials and Devices Research Group
+44 114 222 5181
Full contact details
Department of Electronic and Electrical Engineering
Sir Frederick Mappin Building
I’m interested in computational optics – enhancing optical systems such as microscopes, cameras or projectors with computer code.
My interest began with my PhD at Durham University, where I used computer modelling of the way light propagates to design digital holograms.
The holograms were printed out and projected a 3D pattern of circuitry when illuminated with a laser. We used these projected patterns to expose photoresist for the manufacture of volumetric integrated circuits and 3D antennas.
I spent a year living in the Lake District (where I grew up) after my PhD. I got to indulge my passion for outdoor sports – rock climbing, fell running and triathlon – whilst I was there, so when I decided to return to academia Sheffield was a natural choice, being a very outdoors city with excellent Universities.
I moved to Sheffield to work with Professor John Rodenburg and was lucky enough to join him in the pioneering days of a computational optics technique called ptychography (pronounced tie-cog- ra-fee).
Ptychography uses diffraction pattern measurements to enhance microscopes. It realises ‘perfect’ imaging, where the image of a microscopic specimen it recreates is an exact copy of how that specimen interacts with a beam of light.
I left Sheffield University for a brief spell to work with a spin-out company on commercialisation of ptychography-enhanced microscopes. I missed the freedom of the academic environment, and returned as a Lecturer after a couple of years.
As well as my continuing research in computational optics, I now teach analogue electronics to our third years.
- PhD, University of Durham 2005
- MEng (Electronic & Electrical Engineering), University of Birmingham 2001
- Research interests
- Coherent Diffractive Imaging (CDI)
- Computer-generated holography
- Phase imaging in the Transmission Electron Microscope (TEM)
- Inverse problems
- Image processing
- Ptycho-cam: a ptychographic phase imaging add-on for optical microscopy. Applied Optics, 61(10), 2874-2874.
- Single-pixel ptychography. Optics Letters, 46(7), 1624-1624.
- Efficient large field of view electron phase imaging using near-field electron ptychography with a diffuser. Ultramicroscopy. View this article in WRRO
- Near-field ptychographic microscope for quantitative phase imaging. Optics Express, 26(19), 25471-25480. View this article in WRRO
- Image feature delocalization in defocused probe electron ptychography. Ultramicroscopy, 187, 71-83. View this article in WRRO
- Lensless LED matrix ptychographic microscope: problems and solutions. Applied Optics, 57(8), 1800-1806. View this article in WRRO
- Multi-slice ptychographic tomography. Scientific Reports, 8(1). View this article in WRRO
- Ten implementations of ptychography.. Journal of Microscopy. View this article in WRRO
- Further improvements to the ptychographical iterative engine. Optica, 4(7), 736-745. View this article in WRRO
- Characterizing a spatial light modulator using ptychography. Optics Letters, 42(3), 371-374. View this article in WRRO
- Modal decomposition of a propagating matter wave via electron ptychography. Physical Review A, 94. View this article in WRRO
- Low-Frequency Response of Ptychography in the TEM.. Microscopy and Microanalysis, 22(S3), 510-511.
- Breaking ambiguities in mixed state ptychography. Optics Express, 24(8), 9038-9038. View this article in WRRO
- Quantitative electron phase imaging with high sensitivity and an unlimited field of view. Scientific Reports, 5. View this article in WRRO
- Ptychographic microscope for three-dimensional imaging. Optics Express, 22(10), 12513-12523.
- 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.
- 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. Proceedings of SPIE - The International Society for Optical Engineering, 8338.
- Transmission Diffractive Microscopy Without Lenses at Visible, X-ray and Electron Wavelengths. Microscopy and Microanalysis, 17(S2), 1058-1059.
- 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.
- 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).
- 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.
- High resolution transmission imaging without lenses. Journal of Physics: Conference Series, 241.
- 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.
- Photolithographic patterning of bihelical tracks onto conical substrates. J MICRO-NANOLITH MEM, 6(4).
- Nonplanar photolithography with computer-generated holograms.. Opt Lett, 30(11), 1300-1302.
- Non-planar interconnect. Circuit World, 31(2), 10-14.
- 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
Conference proceedings papers
- A comparison of ptychographic phase retrieval algorithms. Quantitative Phase Imaging V, 2 February 2019 - 7 February 2019.
- Optical ptychography with extended depth of field. Journal of Physics: Conference Series, Vol. 902 (pp 012015-012015) View this article in WRRO
- Ptychography for strongly scattering 3D objects. Optics in the Life Sciences Congress, 2017.
- OPTICAL ARRANGEMENTS FOR PHASE-SENSITIVE IMAGING USING ELECTRON PTYCHOGRAPHY. RECENT TRENDS IN CHARGED PARTICLE OPTICS AND SURFACE PHYSICS INSTRUMENTATION (pp 60-61)
- The Remarkably Flexible Ptychographic Data Set. Optics InfoBase Conference Papers
- Super-resolved Ptychographic Imaging. Microscopy and Microanalysis, Vol. 20(S3) (pp 372-373)
- Three-dimensional Ptychography. Classical Optics 2014, 2014.
- TRANSMISSION AND REFLECTION MICROSCOPY WITHOUT LENSES. RECENT TRENDS IN CHARGED PARTICLE OPTICS AND SURFACE PHYSICS INSTRUMENTATION (pp 61-62)
- A photolithographic process for grossly non-planar substrates - art. no. 69212E. EMERGING LITHOGRAPHIC TECHNOLOGIES XII, PTS 1 AND 2, Vol. 6921 (pp E9212-E9212)
- Non-planar photolithography using digital holograms. Optics InfoBase Conference Papers
- Photolithography on three dimensional substrates. Proceedings - Electronic Components and Technology Conference, Vol. 2006 (pp 283-288)
- Photolithography on grossly non-planar substrates. Proceedings of the Seventh IEEE CPMT Conference on High Density Microsystem Design, Packaging and Failure Analysis (HDP'05) (pp 442-446)
- Teaching activities
- EE335 (integrated electronics)
- EEE6231 (optical imaging systems)
- Postgraduate Research Admissions Tutor
- Research students
Student Degree Status Primary/Secondary Cao S PhD Graduated Secondary