Multiplexed near-field optical trapping

Abstract

Nanophotonic structures optimise the strength of optical forces, enabling trapping at the nanoscale. To improve the impact of nanotweezers in biological studies, it is necessary to move from individual traps to large multiplexed arrays. Here, we discuss the state-of-the-art of nanotweezers for multiplexed trapping, describing advantages and drawbacks of the configurations that have demonstrated the strongest impact in this field. Finally, we focus on our latest results with a dielectric metasurface that supports strong resonances with thousands of trapping sites. We demonstrate near-field enhancement and simulate trapping performance for 100 nm particles, verifying the possibility to trap > 1000 particles with a low total power of P < 30 mW. The multiplexed trapping with dielectric metasurfaces can open up new biological studies on viruses and vesicles.