Optical transport over millimeter distances of a microscopic particle using a novel all-fiber Bessel-like beam generator

Abstract

Whilst free space Bessel modes can show particle guidance over extended distances, this has been limited for fiber-based Bessel-like beams which have importance for microfluidic applications. We propose and experimentally demonstrate a novel all-fiber Bessel-like beam generator (BBG) that is shown transport a dielectric particle distance in excess of 2mm. This was achieved by optimizing the multimode interference (MMI) in the BBG structure to create a Bessel-like beam of appropriate propagation invariant length (PIL) and judicious choice of laser wavelength suppress thermal effects. By varying the diameter of the region where the MMI occurred we analyzed its impact on PIL and the transverse intensity profile of the Bessel-like beam. Our study paves the way for the fiber optic applications such as novel beam shaping, optical transport, and optical imaging.