Enantioselective optical gradient forces using 3D structured vortex light

Here we highlight enantioselective optical gradient forces present in 3D (non-paraxial) structured optical vortex tweezing systems. One chiral force originates from the circular polarization of the light, while remarkably the other is independent of the input polarization - even occurring for unpolarized light – and is not present in 2D structured light nor propagating plane waves. This latter chiral sorting mechanism allows for the enantioselective trapping of chiral particles into distinct rings in the transverse plane through conservative radial forces. •3D structured (non-paraxial) vortex beams act as chiral optical tweezers.•These chiral optical tweezers selectively trap one enantiomer over the other.•One chiral tweezing scheme is independent of the source beam’s polarization.•Radial gradient forces trap enantiomers into distinct rings in the transverse plane.•Remarkably these chiral forces persist even when the input laser beam is unpolarized.