Diffraction of orbital angular momentum carrying optical beams by a circular aperture

Abstract

Far field diffraction of Laguerre-Gauss vortex (LGV) beams of different angular momentum index by a circular aperture placed at different locations with respect to incident beam waist is studied experimentally. The experiments reveal a surprisingly simple structure for the diffraction pattern and its dependence on the orbital angular momentum index of the incident beam when the aperture size is small compared to the beam radius.