Optically levitated conveyor belt based on polarization-dependent metasurface lens arrays

In this Letter, we have proposed an optically levitated conveyor belt based on periodic arrays of a polarization-dependent nanoslit-based metasurface lens (NBML) that is capable of realizing far-field capture, transport, and sorting. The NBML in arrays can be lit up in a relay way by rotating the polarization angle of the excitation beam and thereby provide a better stiffness for transporting particles. When excited at the wavelength of 1064 nm and power density of 0.3 mW/mu m(2), the particles will follow the directional movement of hot spots with an alternative switch of polarization angle and the success ratio of transport can be up to 97.0% with the consideration of Brownian motion. Furthermore, the influence of polarization switching time and incident optical power densities on the efficiency of transport are investigated numerically from a statistical point of view. The sorting of particles with different sizes has also been proved in a given power density. With the analysis of numerical results, our research provides a new approach, to the best of our knowledge, for particle trapping and transport, which is beneficial to on-chip optofluidic applications. (C) 2022 Optica Publishing Group

Automated summary

In this study, an optically levitated conveyor belt based on a nanoslit-based metasurface lens is proposed for capturing, transporting, and sorting particles. By rotating the polarization angle of the excitation beam, the stiffness and success ratio of particle transport can be improved. The influence of polarization switching time and incident optical power densities on transport efficiency are also investigated.