Sveikiname!
MAKSYM IVANOV apsigynė mokslo daktaro disertaciją „Singuliariniai šviesos laukai: generacija S fazine plokštele, išpletimas iki THz ruožo, derinimas parametrinio šviesos stiprinimo metu, ir taikymas šviesos gaudyklei” ir įgijo mokslo daktaro laipsnį.
The main theme of the dissertation is singular light fields. Both singularities of phase (optical vortices) and singularities of polarization (azimuthally/radially aligned polarization distributions) are considered.
Advent of ultra-short pulsed laser systems significantly complicated the process of generation of the singular beams, when pulse consist of different frequency components. This is because of inherent limitation of the conventional beam shaping elements in the terms of acceptable spectral bandwidth. In the first part of this dissertation new methods for the generation of ultra-broadband optical vortices with a geometric phase retarder (S-waveplate) and for enhanced purity of the generated radially/azimuthally polarized beams were demonstrated. Away from the optical region radiation at terahertz (THz) frequencies is gaining more and more practical applications in the recent years. Well developed singular optics methods can be transferred to the THz physics to enhance performance of the THz imaging, short range communication, and electron bunch compression. Therefore, vortex fields were extended to the THz frequencies in the second part of the dissertation. Vortex THz beam was generated from a laser plasma filament induced by a femtosecond pulse consisting of Gaussian fundamental harmonic and optical vortex second harmonic. In the third part of the dissertation, optical parametric amplifier with a tunable polarization state (radial/azimuthal/mixed) was developed. In the last part, optical trapping apparatus, which allows controllable and repeatable experiments on collisional dynamics of micron-sized droplets under gravity was developed together with a method for optical rotation (both spinning and orbiting types of rotation) of a isotropic droplets.
Mokslinis vadovas – prof. dr. Aidas Matijošius
Disertacija rengta 2015–2019 metais Lazerinių tyrimu centre, Vilniaus universitete.
Mokslinius tyrimus rėme Lietuvos mokslo taryba.
Baigęs doktorantūrą ir mokslo daktaro laipsnį įgijęs asmuo geba savarankiškai atlikti mokslinių tyrimų ir eksperimentinės plėtros darbus bei spręsti mokslo problemas. Jis įgija pažangiausių tiriamojo darbo, mokslo sričių ir jų sąveikos žinias, specializuotus gebėjimus ir metodikas mokslinių tyrimų ir kitų sričių problemoms spręsti bei turimoms žinioms ar profesinei praktikai plėsti, gebėjimą dirbti savarankiškai, mokslo ir profesijos išmanymą naujoms idėjoms ar procesams kurti ir panaudoti studijose bei kitoje veikloje.