Author Archives: Tom Vettenburg

Scattering in the Cloud

Clouds in the sky get their white colour from the scattering of light. This is a well-understood phenomenon, yet notoriously difficult to compute. Deep-tissue microscopy relies on controlling light scattering within biological tissue, so we take a particular interest in this issue. By mapping Maxwell’s equations onto the structure of a neural network, we were able to scale up light wave scattering calculations on the cloud, more specifically, the Google Colab cloud.

We integrated this into the open source MacroMax EM solver, ideal for computing coherent scattering in highly-heterogeneous materials such as biological tissue. It is straighforward to install and use with Python. Well within 10 minutes, light wave scattering can now be computed throughout a complex 3D structure with all 3 sides >100μm!

Read more about how this works in our recently published paper doi: 10.34133/icomputing.0098.

Doctoral EngD position with Optos PLC

Do you want to do research with a direct impact on healthcare? Will you help us develop the tools to measure nanoscale neuron activity at the back of the human eye? Early detection is key to prevent the leading causes of blindness. We develop novel optical coherence tomography methods in collaboration with Optos PLC (a Nikon company), and are looking for a doctoral student to join us.

Various open doctoral and postdoc positions

Together with Optos PLC (a Nikon company), we are looking for an EngD research student to develop a new OCT technique for retinal imaging. https://cdtphotonics.hw.ac.uk/project/hybrid-optical-digital-coherence-tomography/ The 4 year doctoral programme includes a 9 months study programme followed by the research project at the company. Start date: September

A similarly study programme is available with Ceres Holographics Ltd, based in the Kingdom of Fife, Scotland. In this project we will develop holographic films for head-up displays and other applications: https://cdtphotonics.hw.ac.uk/project/advanced-holography-for-augmented-reality-head-up-displays/

In collaboration with the School of Life Sciences we are also recruiting a PhD student and two postdoctoral researchers to develop adaptive optical microscopy techniques that enable us to image deeper into biological tissue. This will be tested in close collaboration with developmental biologists to study cell migration in the initial stages of embryo development at the School of Life Science. The researchers will be involved in all stages of the project, from design of the microscope’s adaptive optics to its application in biology, and the computational light propagation and image formation.

More details on the open positions can be found here: https://sites.dundee.ac.uk/vettenburg/jobs/ and https://www.findaphd.com/phds/project/computational-light-microscopy-making-the-invisible-visible/?p133012

Do not hesitate to get in touch if any of these positions sounds interesting to you.

Wavefront Shaping for Biomedical Imaging book available!

wavefront shaping bookTogether with K. Dholakia I authored a book chapter “Shaped Beams for Light Sheet Imaging and Optical Manipulation” in the book “Wavefront Shaping for Biomedical Imaging” (online ISBN: 9781316403938), published by Cambridge University Press: doi:10.1017/9781316403938. For those interested in wavefront shaping and its applications, the book contains many interesting contributions (TOC).

Automated detection of neutropenia

Our work on automated detection of neutropenia is published in the American Journal for Hematology! The blood flow in the capillaries is imaged through the nail-fold skin. Machine learning techniques are applied to detect the location of the capillaries in the image, and spatio-temporal correlations are analysed per capillary. Read more here: doi:10.1002/ajh.25516, and check out the Supporting Info!

Finally a fast algorithm to calculate the light field!

complex scatteringBiological samples, often the subject of optical microscopy, tend to be rather heterogeneous. This affects the propagation of the electromagnetic field of light. While the Maxwell’s laws underlying the propagation of electromagnetic waves in such tissue are well-understood; accurate numerical calculation does not scale well. Even the sub-millimeter-sized sample areas in microscopy pose significant challenges. Recently this changed. Osnabrugge et al. proposed a modification to the efficient Born series that is guaranteed to converge for Helmholtz problems. We have now extended this to solve Maxwell’s equations. The algorithm works for both isotropic and anisotropic dielectric materials, including those with chiral and magnetic properties. Our paper is available on doi:10.1364/OE.27.011946 (open access). The algorithm is made available as a Python library: pip install macromax, documentation and the MacroMax source code with examples can be found on GitHub.