Engineering Optical Force with Nanostructures

Abstract

Light is a powerful tool to manipulate small objects, but existing approaches often require structured light that limits the manipulated object’s shape, material and size. We have proposed and demonstrated a linear nanomotor based on a plasmonic particle that generates, even when illuminated with a plane wave, lateral optical force due to its directional side scattering. This force direction is determined by the orientation of the nanoparticle rather than a field gradient of the incident light. Therefore, the arrangements of the particles allow controlling the lateral force distributions, which can produce movements, as designed, of microobjects in which they are embedded without shaping and steering the laser beam. In other words, instead of tailoring the light beam, we use the embedded nanoparticles to engineer the optical force experienced by the object. Such linear nanomotor would provide a paradigm shift in optical manipulation as it removes the need for shaping and steering the light beam.