All-Fiber Hollow Bessel-Like Beam for Large-Size Particle Trap

A 32 μm large-size microparticle is trapped by an all-fiber hollow Bessel-like beam. In order to realize the proposed high-order Bessel-like beam, we fabricate the optical fiber probe by splicing an annular core fiber with a step-index multimode fiber. We grind the fiber tip into a truncated cone shape to converge the hollow Bessel-like beam to obtain a large focal area. Simulation and experimental results show that the trapping field introduced by the Bessel-like beam provides a relatively strong optical force and has the capability of 3-D capture of a large particle (whose diameter is 32 μm). These highly integrated fiber tweezers provide hollow Bessel-like beams with strong optical force and large trapping area, which can be promisingly applied in biomedical and integrated optical research.