title: Constructing 3D crystal templates for photonic band gap materials using holographic optical tweezers.
abstract: A simple and robust method is presented for the construction of 3-dimensional crystals from silica and polystyrene microspheres. The crystals are suitable for use as templates in the production of three-dimensional photonic band gap (PBG) materials. Manipulation of the microspheres was achieved using a dynamic holographic assembler (DHA) consisting of computer controlled holographic optical tweezers. Attachment of the microspheres was achieved by adjusting their colloidal interactions during assembly. The method is demonstrated by constructing a variety of 3-dimensional crystals using spheres ranging in size from 3 microm down to 800 nm. A major advantage of the technique is that it may be used to build structures that cannot be made using self-assembly. This is illustrated through the construction of crystals in which line defects have been deliberately included, and by building simple cubic structures.
authors: HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK.
authors: D C
authors: DC
authors: Benito
authors: D M
authors: DM
authors: Carberry
authors: S H
authors: SH
authors: Simpson
authors: G M
authors: GM
authors: Gibson
authors: M J
authors: MJ
authors: Padgett
authors: J G
authors: JG
authors: Rarity
authors: M J
authors: MJ
authors: Miles
authors: S
authors: S
authors: Hanna
mesh_terms: D003460:Crystallization / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006696:Holography / Q000379:methods*; D008422:Materials Testing; D052898:Optical Tweezers; D055095:Optics and Photonics / Q000295:instrumentation*; D017785:Photons; D011137:Polystyrenes / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D011137:Polystyrenes; D012822:Silicon Dioxide