On chip optical tractor beam by surface plasmon polariton

Since the discovery, surface wave tractor beams have drawn less attention compared to free-propagating optical tractor beams. For Mie-range objects, this article stands for one of the very first proposals of on chip SPP (surface plasmon polariton) based optical tractor beam where two SPP waves are excited by using gratings made of grooves and meta-surfaces. Such beam can pull dielectric particles within certain size ranges when it is non-paraxial enough. Our SPP tractor beam set-up enables on chip object transportation and radius based optical sorting which could further facilitate the on-chip manipulation and analysis of nanoparticles and biomolecules.