title: Independent polarisation control of multiple optical traps.
abstract: We present a system which uses a single spatial light modulator to control the spin angular momentum of multiple optical traps. These traps may be independently controlled both in terms of spatial location and in terms of their spin angular momentum content. The system relies on a spatial light modulator used in a "split-screen" configuration to generate beams of orthogonal polarisation states which are subsequently combined at a polarising beam splitter. Defining the phase difference between the beams with the spatial light modulator enables control of the polarisation state of the light. We demonstrate the functionality of the system by controlling the rotation and orientation of birefringent vaterite crystals within holographic optical tweezers.
authors.affiliation: Department of Physics & Astronomy, Kelvin Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom. d.preece@physics.gla.ac.uk
authors.forename: Daryl
authors.initials: D
authors.lastname: Preece
authors.forename: Stephen
authors.initials: S
authors.lastname: Keen
authors.forename: Elliot
authors.initials: E
authors.lastname: Botvinick
authors.forename: Richard
authors.initials: R
authors.lastname: Bowman
authors.forename: Miles
authors.initials: M
authors.lastname: Padgett
authors.forename: Jonathan
authors.initials: J
authors.lastname: Leach
mesh_terms: D000465:Algorithms; D003460:Crystallization; D004560:Electricity; D004867:Equipment Design; D006696:Holography / Q000295:instrumentation; D008027:Light; D008846:Micromanipulation; D008853:Microscopy; D015233:Models, Statistical; D052898:Optical Tweezers; D055095:Optics and Photonics; D012029:Refraction, Ocular