Reactive helicity and momentum of tightly focused hybrid polarized vector beams

Abstract Tailoring the reactive helicity and momentum of electromagnetic fields has emerged as a unique way to control light-matter interaction. In this paper, we explore these reactive quantities in hybrid polarized vector beams (HPVBs) that are tightly focused through a high NA objective. By precisely controlling polarization parameter and topological charge, we are able to modulate the hybrid state of polarization for the focused HPVBs, which allows for controllable generation of the reactive helicity and momentum. Notably, we create a purely longitudinal reactive momentum which arises on the beam axis. We also generate a three-dimensional focused spot of the reactive helicity, the size of which can shrink beyond the diffraction limit imposed on light intensity spots. These findings provide new insights into the dynamic properties of structured light, and would have implications for optical manipulation techniques including particle trapping, pulling and rotation.