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Abstract
This thesis explores advanced manipulation and control of light’s structure, focusing on the degrees of freedom such as phase, polarization, and coherence. The research primarily addresses the generation, propagation, and application of structured optical beams, with significant implications for imaging, communication, particle manipulation, microscopy, and quantum state engineering.A key area of investigation is the use of orbital angular momentum (OAM) in optical beams. These beams, characterized by a conserved topological charge, have shown promise in free-space optical communication due to their resilience against amplitude and phase disturbances. The research highlights the development of partially coherent beams that maintain deterministic vortices at specific propagation distances, achieved through fractional Fourier transforms (FracFTs) applied to Schell-model vortex beams in the source plane.Another significant focus is on polarization singularities in fields with two harmonic frequencies, i.e. Lissajous singularities. The study reveals stable Lissajous singularities within the beam core, offering new opportunities in high-precision metrology and secure communication. Additionally, Young’s interference experiment with bichromatic vector beams is simulated creating Lissajous-type polarization singularities, enhancing the fundamental understanding of the conditions under which Lissajous singularities can be created in interference.This work integrates these findings into a comprehensive framework for structured coherence beams, advancing theoretical models and experimental techniques. The resulting beams demonstrate unprecedented control over intensity, phase, coherence, and polarization, paving the way for innovative applications in optical science and engineering.