title: Acousto-optically generated potential energy landscapes: potential mapping using colloids under flow.
abstract: Optical potential energy landscapes created using acousto-optical deflectors are characterized via solvent-driven colloidal particles. The full potential energy of both single optical traps and complex landscapes composed of multiple overlapping traps are determined using a simple force balance argument. The potential of a single trap is shown to be well described by a Gaussian trap with stiffness found to be consistent with those obtained by a thermal equilibrium method. We also obtain directly the depth of the well, which (as with stiffness) varies with laser power. Finally, various complex systems ranging from double-well potentials to random landscapes are generated from individually controlled optical traps. Predictions of these landscapes as a sum of single Gaussian wells are shown to be a good description of experimental results, offering the potential for fully controlled design of optical landscapes, constructed from single optical traps.
authors.affiliation: Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK. michael.juniper@chem.ox.ac.uk
authors.forename: Michael P N
authors.initials: MP
authors.lastname: Juniper
authors.forename: Rut
authors.initials: R
authors.lastname: Besseling
authors.forename: Dirk G A L
authors.initials: DG
authors.lastname: Aarts
authors.forename: Roel P A
authors.initials: RP
authors.lastname: Dullens
mesh_terms: D000465:Algorithms; D003102:Colloids / Q000737:chemistry*; D004735:Energy Transfer; D061088:Photoacoustic Techniques / Q000379:methods*; D012212:Rheology / Q000379:methods*
chemical_list: D003102:Colloids