Kulchukova, Zhamila2023-06-022023-06-022023Kulchukova, Zh. (2023). Vortex ring reconnections in paraxial laser beams. School of Sciences and Humanitieshttp://nur.nu.edu.kz/handle/123456789/7179In recent years, optical vortex knots have been the subject of active research. The knots appear in various areas of physics and understanding the mechanism that is responsible for their formation is a problem that extends beyond optics. However, due to their spontaneous nature, it is impossible to predict their location. To unravel such a complex problem, it is important to understand simpler systems that may allow for the generation of vortex knots. In this thesis, I investigate the interference between the elliptical Gaussian beam and the plane wave, as a result of which vortex rings appear. The rings are basically the unknots, and the ellipticity allows for ring deformations. Consequently, at certain parameters, the rings are able to reconnect. I identify two types of ring reconnections: the reconnection that merges the rings together, and the self-crossing, where a loop-like structure is formed from a single ring crossing itself. This study has the potential to pinpoint specifics of the underlying mechanism that causes spontaneous knottings.enAttribution-NonCommercial-ShareAlike 3.0 United StatesType of access: Open Accessparaxial laser beamsVortex ring reconnectionsBachelor's thesis