Influence of geometric shape of optically trapped particles on the optical rotation induced by vortex beams

摘要

Particles optically trapped and rotated in fluidic medium by a vortex beam receive a torque exerted by orbital angular momentum of the beam. Size and shape of the trapped particles are found to affect the rotation remarkably; e.g., a lump of particles is easier to be set in rotation than a single particle, and a row of particles stuck to each other will rotate faster than isolated particles. Influences of the size and arranging manner of a group of particles on the rotation are investigated analytically and experimentally.