title: Nano-optical conveyor belt, part II: Demonstration of handoff between near-field optical traps.
abstract: Optical tweezers have been widely used to manipulate biological and colloidal material, but the diffraction limit of far-field optics makes focused beams unsuitable for manipulating nanoscale objects with dimensions much smaller than the wavelength of light. While plasmonic structures have recently been successful in trapping nanoscale objects with high positioning accuracy, using such structures for manipulation over longer range has remained a significant challenge. In this work, we introduce a conveyor belt design based on a novel plasmonic structure, the resonant C-shaped engraving (CSE). We show how long-range manipulation is made possible by means of handoff between neighboring CSEs, and we present a simple technique for controlling handoff by rotating the polarization of laser illumination. We experimentally demonstrate handoff between a pair of CSEs for polystyrene spheres 200, 390, and 500 nm in diameter. We then extend this technique and demonstrate controlled particle transport down a 4.5 μm long "nano-optical conveyor belt."
authors.affiliation: Department of Electrical Engineering, ‡Department of Applied Physics, and §Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.
authors.forename: Yuxin
authors.initials: Y
authors.lastname: Zheng
authors.forename: Jason
authors.initials: J
authors.lastname: Ryan
authors.forename: Paul
authors.initials: P
authors.lastname: Hansen
authors.forename: Yao-Te
authors.initials: YT
authors.lastname: Cheng
authors.forename: Tsung-Ju
authors.initials: TJ
authors.lastname: Lu
authors.forename: Lambertus
authors.initials: L
authors.lastname: Hesselink