title: Controlled rotation of optically trapped microscopic particles.
abstract: We demonstrate controlled rotation of optically trapped objects in a spiral interference pattern. This pattern is generated by interfering an annular shaped laser beam with a reference beam. Objects are trapped in the spiral arms of the pattern. Changing the optical path length causes this pattern, and thus the trapped objects, to rotate. Structures of silica microspheres, microscopic glass rods, and chromosomes are set into rotation at rates in excess of 5 hertz. This technique does not depend on intrinsic properties of the trapped particle and thus offers important applications in optical and biological micromachines.
authors.affiliation: School of Physics and Astronomy, St. Andrews University, North Haugh, St. Andrews, Fife KY16 9SS, Scotland.
authors.forename: L
authors.initials: L
authors.lastname: Paterson
authors.forename: M P
authors.initials: MP
authors.lastname: MacDonald
authors.forename: J
authors.initials: J
authors.lastname: Arlt
authors.forename: W
authors.initials: W
authors.lastname: Sibbett
authors.forename: P E
authors.initials: PE
authors.lastname: Bryant
authors.forename: K
authors.initials: K
authors.lastname: Dholakia
mesh_terms: D000818:Animals; D002875:Chromosomes; D006224:Cricetinae; D003412:Cricetulus; D005898:Glass; D007834:Lasers; D008846:Micromanipulation; D008863:Microspheres; D055095:Optics and Photonics; D012399:Rotation; D012822:Silicon Dioxide
chemical_list: D012822:Silicon Dioxide