Conical-angle-modulated continuous optical bottles beam for annular micromanipulation
摘要
Optical bottle beams, as structured light fields, are important for optical micromanipulation as they enable stable three-dimensional trapping of particles during propagation. A strategy to generate optical bottle beams is to introduce a modulation of the conical angles in a dual-ring configuration, but the extent of the control of optical micromanipulation achievable by this modulation is still unknown. Here, we generate a highly controllable continuous optical bottles beam (COBB) via superposition of two circular Airyprime vortex beams with conical-angle modulation. We study the effects of conical angles γ1 and γ2 on the number, spatial position, and intensity of the COBB, revealing its generating mechanism, propagation and evolution dynamics. The COBB is then integrated into an optical tweezers system for orbital micromanipulation of polystyrene microspheres. At fixed laser power, we demonstrate the ability of our COBB to tune the annular trap radius from 1.10 µm to 2.02 µm by tuning the rotation speed from 1.32 to 3.71 rad s-1 at fixed topological charge. Our results show that conical-angle-modulated COBB provides a scalable physical framework for advanced optical micromanipulation in optical bottle configurations.