Pasko V. Topological reactions and transformation of the orbital angular momentum spectrum in optical beams

The first part of the thesis is devoted to theoretical investigation of topological reactions which take place in an optical wave with linear edge dislocations of the wave front (transversal optical vortices). The optical field with edge dislocations was simulated by means of destructive interference of two cylindrical Gaussian beams. The main stages of annihilation of the transversal optical vortices and unfolding of the edge dislocation were investigated. In the second part of the thesis an analysis of optical field structure for waves with optical vortices produced by the binary computer-generated holograms was carried out. In particular, optical vortex beams with integer and ? fractional topological charges were investigated. For such beams the amplitude distributions in the far field were found. It was shown, that the optical vortex beam with ? fractional topological charge can be represented in the far field as a superposition of a vortex-free component and axial single-charged optical vortex. The third part is devoted to investigation of the orbital angular momentum of laterally displaced and angularly deflected optical beams. An analysis was accomplished for Gaussian beam and Laguerre-Gaussian modes. The orbital angular momentum spectra were found for each case and dependence of these spectra on the displacement or the deflection angle was shown. For rotated laterally displaced or angularly deflected beam the existence of discrete frequency spectrum, which is related to the orbital angular momentum spectrum was demonstrated.