Professor Andrew Maiden
PhD, MEng
School of Electrical and Electronic Engineering
Professor of Computational Imaging
Semiconductor Materials and Devices Research Group
Full contact details
School of Electrical and Electronic Engineering
Sir Frederick Mappin Building
Mappin Street
Sheffield
S1 3JD
- Profile
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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 FRS, 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 Digital Signal Processing (DSP) to our third years.
- Research interests
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- Coherent Diffractive Imaging (CDI)
- Ptychography
- Computer-generated holography
- Phase imaging in the Transmission Electron Microscope (TEM)
- Inverse problems
- Image processing
- Publications
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Journal articles
- Deep-ultraviolet ptychographic pocket-scope (DART): mesoscale lensless molecular imaging with label-free spectroscopic contrast. eLight, 6(1).
- Depth of field of multi‐slice electron ptychography: investigating energy and convergence angle. Journal of Microscopy. View this article in WRRO
- Electron Ptychography in the Fresnel Diffraction Regime. Microscopy and Microanalysis, 31(Supplement_1).
- Investigating the Effect of Update Strengths for Atomic-Resolution Low-Dose Imaging in Iterative Ptychography. Microscopy and Microanalysis, 31(Supplement_1).
- Assessing Ptychographic Methods for Maximum Low Dose Performance. BIO Web of Conferences, 129, 04034-04034.
- Computational optical sectioning via near-field multi-slice ptychography. Optics Letters, 49(17), 4839-4842. View this article in WRRO
- Comparing Ptychographic Methods for Maximum Low Dose Performance. Microscopy and Microanalysis, 30(Supplement_1).
- Ptycho-endoscopy on a lensless ultrathin fiber bundle tip. Light: Science & Applications, 13(1). View this article in WRRO
- WASP: weighted average of sequential projections for ptychographic phase retrieval. Optics Express, 32(12), 21327-21344. View this article in WRRO
- Lorentz near-field electron ptychography. Applied Physics Letters, 123(19). View this article in WRRO
- Spatial- and Fourier-domain ptychography for high-throughput bio-imaging. Nature Protocols, 18(7), 2051-2083. View this article in WRRO
- Near-field multi-slice ptychography: quantitative phase imaging of optically thick samples with visible light and X-rays. Optics Express, 31(10), 15791-15791. View this article in WRRO
- Ptychography at all wavelengths. Nature Reviews Methods Primers, 5(1).
- Introduction to the Special Issue on ptychography. Journal of Microscopy.
Conference proceedings
- RETHINKING ASSESSMENT: LARGE-SCALE THRESHOLD AND GRADING ASSESSMENT IN ENGINEERING. Sefi 2025 53rd Annual Conference of the European Society for Engineering Education Engineering and Society Proceedings (pp 823-831)
- Near-field multi-slice optical ptychography. Optica Imaging Congress 2024 (3D, AOMS, COSI, ISA, pcAOP) (pp CW3B.1-CW3B.1), 2024.
Preprints
- Residual neural-field ptychography for dose-efficient electron, X-ray, and optical nanoscopy, arXiv.
- Deep-ultraviolet ptychographic pocket-scope (DART): mesoscale lensless molecular imaging with label-free spectroscopic contrast, arXiv.
- Ptycho-endoscopy on a lensless ultrathin fiber bundle tip, arXiv.
- Set projection algorithms for blind ptychographic phase retrieval, arXiv.
- Magnetic Phase Imaging using Lorentz Near-field Electron Ptychography, arXiv.
- Deep-ultraviolet ptychographic pocket-scope (DART): mesoscale lensless molecular imaging with label-free spectroscopic contrast. eLight, 6(1).
- Teaching activities
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- EEE309 - Introduction to Digital Signal Processing
- EEE339 - Digital Engineering