The optical tweezers technique has attracted extensive interest and is playing an important role in manipulating nano/micro-objects in many fields. However, number of the trapped particles are always imprecise in classical techniques, to form uncontrollable clusters at the focus. Yet, precise manipulation of a specific objective is of vital importance in many situations. Many approaches have been proposed and implemented to assist pulling or pushing forces for specific traps. They could modulate a hybrid plasmonic field to achieve a single trap while rejecting other particles, however, control of the trapping dynamics is still lacking. A simple and direct way to achieve selective trapping is still urgently needed. As trapping commences with the distribution of the optical field, tailoring the field distribution is a direct way to modulate the force and trapping results. Recently, the sharply developed metasurface technique provides a novel approach for this. We designed a chiral sensitive metalens to tailor the optical field by focusing the left-circular polarization but produces a diverging right-circular polarization beam with opposite focal length. Consequently, two independent plasmonic fields are excited at the surface plasmon resonance angle, and propagate oppositely to assist trapping and anti-trapping forces simultaneously. Combining the effects of two orthogonal circular polarizations, single target particle was stably trapped in the center while all other particles were repelled. Both theoretical simulations and experimental results validate the effectiveness of the proposed method. This points toward targeted manipulations that may find applications in single-particle assistant molecular Raman detection and assembly of plasmonic structures.
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