Focusing surface plasmon polariton trapping of colloidal particles

We report focusing surface plasmon polariton (SPP) trapping of colloidal particles without optical interactions. Using a silver nanostructure, we demonstrate SPP launching and propagation under a p-polarized incident laser. In-plane Fresnel zone plate (FZP) is used to focus the SPP waves. Colloidal particles can be trapped at the silver nanostructure in the illumination region and the FZP focus area by focusing SPP force. The SPP tweezers open new perspectives in the subwavelength trapping and applications to lab-on-chip devices.Physics, AppliedSCI(E)EI18ARTICLE6null9