Fiber-Optic Probes for Ring-Shaped Multiparticle Capture

Conventional single-fiber optical tweezers usually capture particles at the front or side end of the tip of a fiber probe, thus enabling optical manipulation of particles in a limited range. In this article, we design and fabricate a novel single-fiber probe, which is prepared by integrating a common single-mode fiber (SMF) and a silica capillary microtubular fiber (COF) and the excitation of LP21 higher order modes in fiber-optic probes, and its output light field has multiple focused light traps, which enhances the intensity of the light field at the edge of the light probe and capable of capturing and manipulating multiple 3-
$\mu \text{m}$
-diameter polystyrene (PS) particles simultaneously in a circular multidirectional manner, thus breaking the limitation of the direction of the light capture and expanding the spatial range of the light capture. Simulation and experimental results demonstrate the feasibility of the fiber probe. The excitation and application of multimode beams in this new fiber probe improves the capture efficiency of single-fiber probes and is easy to prepare, and it enriches the functionality of a single-fiber optic probe, which is expected to be applied in the field of micro-objects research, such as the collection of multiple cells in biomedicine and the manipulation of multiple particles.