All dielectric metalens for optical remote rotation manipulation of single and multiple particles

Abstract

This paper delves into the particle manipulation of an all-dielectric metalens, capable of achieving non-contact optical control of particles over a certain distance. The core function is the optical remote manipulation of single and multiple particles, enabling the particles to rotate along the specific optical vortex (OV). The structure of this metalens is based on the Pancharatnam-Berry (PB) phase principle, which constructs a specific phase distribution that results in a vortex electric field distribution in the far field. We investigate the effects of factors such as topological charge numbers, particle radius and refractive index on performance in the single-particle scenario. For the polystyrene (PS) particle with a radius of 300 nm, it can perform a counterclockwise rotation with a radius of about 0.73 μm. The maximum tangential optical force is 54.5 pN, with a maximum torque of 6.98 × 10⁻¹² m²/s, and the radial potential well depth reaches up to 960.4 k_BT when the topological charge number is 3, resulting in an optimal comprehensive rotational manipulation effect.We also explore scenarios in which multiple particles enter the OV in different manners, comparing the magnitude of optical forces under the same conditions with those of single particle. The input of particles from one side of the OV ensures that the overall manipulation performance is not compromised, with the maximum optical force reaching 109.2 pN. The finding provides a more universal approach to remote control of particles, laying the foundation for more complex and highly integrated far-field particles manipulation and broadening the promising prospects of all-dielectric metalens in the near-infrared wavelength range.