Sculpting optical energy landscapes for multi-particle nanoscale assembly

Bradshaw, David, Forbes, Kayn and Andrews, David (2014) Sculpting optical energy landscapes for multi-particle nanoscale assembly. In: UNSPECIFIED.

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    Abstract

    To understand the forces and dynamics of two or more neutral particles trapped within an optical beam, careful consideration of the influence of inter-particle forces is required. The well-known, field-independent intrinsic force is known to derive from the Casimir-Polder interaction. However, the magnitude of this force may be over-ridden by the effect known as optical binding, in cases when the laser beam is of sufficient intensity. This binding interaction is completely independent of optomechanical effects relating to optical tweezers, and involves a stimulated (pairwise) forward-scattering process. Unlike the Casimir-Polder coupling, optical binding is not always an attractive force when both particles are in their ground state. Associated with optical binding are potential energy surfaces, which reveal intricate patterns of local minima – sets of positions in which one of the particles will sit at equilibrium (with the other notionally set at the origin). These optical energy landscapes, which can be illustrated by use of contour diagrams, have mostly been considered for systems in which spherical particles are optically bound. The effect of different particle shapes, for example tube-like structures, can also be explored. Moreover, although the theory of conventional optical binding generally assumes situations in which both particles reside in their ground states, new results arise when individual particles are excited to a higher electronic state. Although, in the experimentally most convenient structural configuration (for tumbling spherical particles), pairwise optical binding vanishes in the short-range region, novel effects can arise as a result of non-zero optical binding between three neighbouring particles.

    Item Type: Conference or Workshop Item (Paper)
    Faculty \ School: Faculty of Science > School of Chemistry
    Faculty of Science
    University of East Anglia > Faculty of Science > Research Groups > Physical and Analytical Chemistry
    Related URLs:
    Depositing User: Pure Connector
    Date Deposited: 09 Jul 2014 12:58
    Last Modified: 25 Jul 2018 02:08
    URI: https://ueaeprints.uea.ac.uk/id/eprint/49394
    DOI: 10.1117/12.2051207

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