The state of spatial coherence of a partially coherent optical source plays the crucial part in free-space evolution of the major properties of the radiated beam, such as its diffraction rate, spectral composition, intensity distribution and polarization/Orbital Angular Momentum (OAM) states. In particular, various effects of source coherence on the beam properties relating to its OAM structure, such as spatial profiling of the vortex core, vortex self focusing, average intensity rotation, etc. have also been illustrated. To account for such coherence effects most efficiently, the treatment of the OAM content in stationary sources and beams with the help of Coherence-OAM (COAM) matrices was recently suggested and is overviewed here. A possible approach to analytical modeling of the COAM matrices is then discussed. A calculus characterizing the OAM transformations, analogous to the Jones-Stokes-Mueller calculi used in polarization optics, was also recently introduced for thin (local) and extended (non-local) devices. Here, we consider the combination of a local and a non-local device to suggest an OAM-resolved imaging system, as a possible application.
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