Enantioselective optical forces and size-dependent sorting of single chiral particles using vortex beams

Abstract

We put forward an approach to manipulate and enantioselect chiral microspheres using vortex beams that encode topological charges. Vortex beams with different topological charges transfer angular momentum to chiral particles with opposite handedness in a different way. This process also depends on the incident polarization, in a rich interplay that ultimately leads to enantioselective optical forces acting on single chiral particles with selected, arbitrary sizes. Besides this scheme also depends on the order of the topological charge, which can also be controlled experimentally. The resulting enantioselective optical forces are up to two orders of magnitude larger than the existing chiral resolution methods based on optical forces, further demonstrating the unique functionalities and applicability of the method.