Optomechanical Wagon-Wheel Effects for Bidirectional Sorting of Dielectric Nanoparticles

The visual perception of a moving target is not always true. Wheels turning rapidly, for instance, may look like rotating inversely. This phenomenon is known as the wagon-wheel effect (WWE) and it is caused by the undersampling of visual information. Here, an analogous manifestation of the WWE concept is described in the scenario of light-matter interactions, by showing that the dynamic response of a particle, to an optical trap scanned at different rates, can be diametrically opposed. Further, such behaviors are modulated by the particle dimensions, which can be exploited for particle size selection. The results uncover a distinct paradigm of nontrivial optical manipulation and expand the bidirectional optical sorting range of dielectric particles to the sub-200 nm scale.

Automated summary

The study presents a unique optical manipulation phenomenon in light-matter interactions, where the dynamic response of particles to an optical trap can be diametrically opposed. The phenomenon, modulated by particle dimensions, can be utilized for particle size selection.