Abstract

Fraunhofer diffraction pattern is apparently Fourier transform of the aperture function. But when the beam possesses orbital angular momentum (OAM) it exhibits strangely different diffraction patterns that abides by charge conservation rule [1]. The azimuthally varying phase of scalar-field singularities effecting diffraction patterns has been rigorously discussed in the literature considering various shape of the apertures. This aspect has already been utilized in phase retrieval and OAM detection [1]. In this work, peculiar diffraction behaviour of vector-field singularities [2, 3], that are superposition of oppositely charged OAM beams in orthogonal polarized states, on passing through a diamond shaped aperture is investigated. Integrating spatially inhomogeneous polarization to the diffracting beams although increases the inherent complexity, unveils interesting polarization transformations.

© 2019 Japan Society of Applied Physics, The Optical Society (OSA)