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Lewis Atsu, MSc

Personal Profile

My name is Lewis Atsu Asilevi from Ghana, currently a PhD student at the University of Eastern Finland. I enrolled into the Master’s Degree Program in Photonics in November 2015 and graduated in June 2017. Since then, I have been partly on intermittent short term research projects until September 2019 when I dedicated my full time to the pursuit of my research interest as a PhD candidate in the field of electromagnetic surface waves (ESW). ESW are nothing but the analogue of the ocean surface waves we observe at the beach.


Specifically, my research concerns firstly, the generation of these waves in specially and carefully designed nanophotonic structures that are several hundred times thinner than the human hair. Secondly, the properties of these generated surface waves are studied. We can study properties such as the spatial and temporal coherence properties of these waves, a relatively new area in this field.

Applications are a natural consequence of these studies.This research topic is of tremendous importance to me because these ESW can be generated
and localised in very tight regions of space even beyond the diffraction limit of light. This means that, we can build devices that are smaller than the wavelength of light for example. Also, in the future, when electronic circuits are replaced by photonic circuits, we can expect smaller photonic circuit components compared to their equivalent electronic circuits with an
unparallel performance exploiting these ESW. In addition to being tightly localised in space, they can be tens of times more intense in these localised regions when compared to the intensity of the source. These makes them essential sources for non-linear optics study.

More than half of my research hours is dedicated to the development of computational algorithm for the study of these ESW. Interestingly, I had no clue of what my interest really was even after completing my MSc. When I got put on my current project, my interest was gradually moved towards the computational and design aspect of the project. All the theoretical
and mathematical knowledge acquired during my MSc started finding usefulness when I began this journey.


However, this new interest required and still requires hours upon hours in front of a computer writing computational algorithms and it can be really challenging sometimes. But for me, when these tools are finally working and I apply them to rigorously study these electromagnetic phenomena, it brings me a great sense of accomplishment and motivates me to push harder even in the face of so many obstacles. I hope to push forward and contribute my quota to the pool of scientific knowledge when I complete my PhD studies.


Seeing how useful a skill in computational physics could be to any individual, in the long term, I see myself dedicating my full time to theoretical Physics and the development of computational algorithms
to solve the world’s problems.

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