In the proposed mini phase microscope instead of lenses, a custom-made diffractive element, a small-pixeled binary phase mask is used along with state-of-the-art phase retrieval-based algorithms to achieve the high-resolution reconstruction of complex-valued objects.
One of the key elements of the developed algorithm is a novel idea of computational separation of the carrying and objects’ wavefronts. To have a correct computational model of the carrying wavefront the study conducts two calibration experiments.
Such an approach is highly robust, since it corrects discrepancies between computational models and fundamental optical elements and, therefore, improves the fidelity of the reconstruction algorithm.
Therefore, in implementation, the proposed system is a compact, portable, and cost-effective alternative to the cumbersome and expensive traditional phase imaging systems.
“We expect that the quality high-resolution phase imaging along with the setup simplicity – without a lens and moving elements – be of special interest to the general public and the optical community”, says Péter Kocsis.
Moreover, the single-shot property allows dynamic scene recording. The successful video reconstruction of a moving single-celled eukaryote presented in the dissertation is unique since as he states, “to the best of our knowledge it is the first super-resolved video reconstructed by phase retrieval with an adequately high frame rate”.
Péter Kocsis is originally from Hungary and has worked in Finland as a doctoral researcher since 2018. He moved back to Hungary in 2022 and he is working now as an optical developer at Robert Bosch GmbH., focusing on sharpness expertise and data analysis.
The doctoral dissertation of MSc (Tech) Péter Kocsis in the field of Information technology, titled Lensless Single-shot Pixel Super-resolution Phase Microscopy will be publicly examined in the Faculty of Information Technology and Communication Sciences at Tampere University at 12 o’clock on Wednesday 7.12.2022 via remote connection. The Opponent will be Professor Vijayakumar Anand from the University of Tartu, Estonia. The Custos will be Professor Karen Eguiazarian from the Faculty of Information Technology and Communication Sciences at Tampere University.
The dissertation is available online.
Photo: Nikolett Kocsis