title: Lateral optical binding between two colloidal particles.
abstract: An optical binding force between two nearby colloidal particles trapped by two coherent laser beams is measured by phase-sensitive detection. The binding force is long-range and spatially oscillatory. For identical linearly-polarized incident beams, the oscillation period is equal to the optical wavelength. For mutually perpendicular polarizations, a new force appears with half-wavelength periodicity, caused by double inter-particle scattering. This force is observable only with cross-polarized incident beams, for which the stronger single-scattering forces are forbidden by parity.
authors.affiliation: Bioengineering Program, Lehigh University, USA.
authors.forename: Ming-Tzo
authors.initials: MT
authors.lastname: Wei
authors.affiliation: Department of Physics and Institute of Computational and Theoretical Studies, Hong Kong Baptist University, Hong Kong.
authors.forename: Jack
authors.initials: J
authors.lastname: Ng
authors.affiliation: Physics Department, Hong Kong University of Science and Technology, Hong Kong.
authors.forename: C T
authors.initials: CT
authors.lastname: Chan
authors.affiliation: Bioengineering Program, Lehigh University, USA.|Physics Department, Lehigh University, USA.
authors.forename: H Daniel
authors.initials: HD
authors.lastname: Ou-Yang