Optically-driven Rotation of Perfectly Absorbing Nanoparticles

Abstract

Optical manipulation of small scatterers assisted with auxiliary nanostructures is a very promising and already proven concept. In this work, we investigate an interesting application of angular momentum transfer in light scattering by dielectric nanoparticles. We show that, when illuminated by a circularly polarized plane wave, the scattered Poynting vector from a homogeneous dielectric cube presents a divergence-free component. Such Poynting vector distribution induces rotational motion via angular momentum transfer to any strong absorbing particle in the vicinity of the scatterer. We illustrate this effect in the case perfectly absorbing dipolar nanoparticles. The proposed design is the first step towards an efficient all-dielectric mixing scheme for micro-fluidics applications.