On the importance of the longitudinal component of paraxial optical vortices in the interaction with atoms

Abstract

Experimental evidence and theory on the head-on excitation of atoms by paraxial Laguerre–Gaussian beams revealed that the longitudinal component of the field has to be taken into account. Optical vortices are in fact a large family of fields, Laguerre–Gaussian being only one particular case. Here, we extend the previous study to a broader set of vortex fields. We demonstrate that, in general, paraxial optical vortices that have opposite orbital and spin angular momenta exhibit a longitudinal component that cannot be disregarded in the light–matter interaction.