Professor
Andrew
Maiden
PhD, MEng
School of Electrical and Electronic Engineering
Professor of Computational Imaging
Full contact details
Sir Frederick Mappin Building
- Profile
-
I am 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. These 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
-
- Coherent Diffractive Imaging (CDI)
- Ptychography
- Computer-generated holography
- Phase imaging in the Transmission Electron Microscope (TEM)
- Inverse problems
- Image processing
- Publications
-
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
- 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.
- Deep-ultraviolet ptychographic pocket-scope (DART): mesoscale lensless molecular imaging with label-free spectroscopic contrast. eLight, 6(1).
- Teaching activities
-
- ELE346, Digital Signal Processing
- ELE339, Digital Engineering
- Professional activities and memberships
-
- Fellow of Royal Microscopical Society
- Member of Optical Society
- Editorial Boards of Journal of Microscopy and Ultramicroscopy
- Grant reviewer for UKRI/ERC/EPSRC/SNSF/PSC/DRC