This thesis explores advanced manipulation and control of light’s structure, focus-
ing 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 manipula-
tion, 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 singulari-
ties within the beam core, offering new opportunities in high-precision metrology and
secure communication. Additionally, Young’s interference experiment with bichro-
matic 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.