Plasmonic Manipulation of Targeted Metallic Particles by Polarization-Sensitive Metalens

As a tool in the manipulation of micro- and nano-objects, optical tweezers are found in applications in many areas. However, selective trapping still poses challenges. Recently, a meta-surface technique offers an approach to improve optical trapping and manipulation capabilities. Here, we demonstrate the selective trapping of metallic nanoparticles with tailored plasmonic fields using a polarization sensitive metalens. We show, both by theory and experiments, modulated trapping and antitrapping forces when beam polarizations are tuned. Combining the effects of two orthogonal circular polarizations, single target particles were stably trapped in the center, while all other particles were repelled. This particle isolation points toward targeted manipulations that may find applications in single-particle assistant molecular Raman detection and assembly of plasmonic structures.