Open vortex beams as optical conveyor belts for programmable particle transport and sorting

Optical manipulation using structured light has become a cornerstone technique, propelling the development of laser-based applications in diverse fields such as biology, medicine, and chemistry. Conventional optical tweezers researches predominantly explore trapping multiple particles simultaneously. To meet the demand for asynchronous manipulation of multiple particles, a versatile optical trapping platform based on the open vortex beams (OVBs) is presented that utilizes their intensity gradients to achieve partitioned manipulation of both high- and low-refractive-index (HRI/LRI) particles. The particular optomechanical effects of proposed beam are demonstrated by three groups of the experiments including guided particles motion along programmable trajectories, Newton's cradle-like collective dynamics, and size-selective particle sorting. For HRI particles, sequential momentum transfer results from the combined action of an azimuthally modulated intensity gradient force and the particles' inherent inertia, which together constitute a previously unexplored coupled transmission mechanism. Meanwhile, the sorting of the LRI particles is completed by a differential response to optical forces. Building on this foundation, we further investigate the optical field properties and manipulation capabilities of OVB arrays, demonstrating their reconfigurability into arbitrary predefined modes for complex manipulations of particles. This proposed approach provides a versatile and efficient platform for targeted particle manipulation and separation, while also providing a new insight into optomechanical coupling in structured light fields.