title: Photophoretic trapping of multiple particles in tapered-ring optical field.
abstract: We demonstrate the photophoretic trapping of more than several hundreds of absorbing particles by tapered-ring optical traps diffracted from a circular aperture. The experiments with different laser powers show the influence of air flow acting on particles. Three kinds of particles with different densities (about 1~7 g/cm(3)) and different shapes (spherical, non-spherical) can be trapped. The non-spherical particles (toner particles) disperse in optical field, while the spherical particles (ink droplets and iron particles) arrange as a straight line. More importantly, in the experiments of two counter-propagating tapered-ring beams, the agglomeration of particles is achieved and can help research the dynamics of aerosols.
authors.forename: Fengrui
authors.initials: F
authors.lastname: Liu
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Wei
authors.forename: Qingchuan
authors.initials: Q
authors.lastname: Zhang
authors.forename: Teng
authors.initials: T
authors.lastname: Cheng
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Wu
mesh_terms: D000336:Aerosols; D004867:Equipment Design; D007834:Lasers; D008027:Light; D052898:Optical Tweezers
chemical_list: D000336:Aerosols