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Paulius Šlevas, a researcher at the Department of Fundamental Research of Center for Physical Sciences and Technology (FTMC), has been awarded a Doctor of Science degree. He defended his dissertation on the topic "Methods for the formation of structured light beams and their application for laser microprocessing" in the field of physics (scientific supervisor Dr Sergejus Orlovas).

Congratulations to our colleague and best wishes for innovative scientific discoveries!

Paulius' dissertation is on the formation of structured laser beams. The most common laser systems use Gaussian beams, which can be compressed to small dimensions by lenses. However, it does not maintain these dimensions as it propagates through space, so many laser micromachining tasks require scanning this beam at multiple heights.

"In addition to Gaussian beams, non-diffracting beams such as Bessel and Airy beams are also known. They have a high ratio between the longitudinal and transverse dimensions of the main intensity peak, i.e. they maintain their dimensions over long propagation distances. When processing transparent materials, this allows a single laser pulse to modify a larger volume of the material and accelerate the process. In my work, I have explored methods to create complex light structures from non-diffracting beams with multiple parallel or entangled high intensity peaks, which would further accelerate processes such as laser fabrication of circular trajectories.

I hope that this work will stimulate public interest in laser technology and laser processing. Non-diffracting beams, such as the Bessel beams, are already excellent for laser microprocessing tasks such as cutting glass or drilling holes. I very much hope that the results of my work will lead to the use of other, even more exotic beam profiles, to further encourage research of these beams and that ultimately this will result as a reduction in the cost of electronic or medical products” says the new Doctor of Physics.

When asked what he enjoys most about his work, Paulius said: "This research has shown that by stacking multiple Airy beams, it is possible to experimentally form an optical needle with controllable ellipticity. By combining different vortical Bessel beams, it is possible to experimentally form arrays of parallel or braided intensity peaks that maintain their shape over long propagation distances. What is particularly pleasing is that such light structures are able to modify large volumes of transparent materials by a single laser pulse compared to a conventional Gaussian beam."