title: Optical waveguiding in suspensions of dielectric particles.
abstract: An optical waveguide formed by a suspension of dielectric nanoparticles in a microchannel is described. The suspensions, chosen for their guiding and scattering properties, are silica and polystyrene particles that have diameters of 30-900 nm and are dispersed in water with volume fractions up to 10%. Changing the diameter and concentration of the particles causes the suspensions to transition from Rayleigh to Mie scattering and from single to multiple scattering. The threshold for optical guiding in a waveguide core composed of these suspensions is set by the numerical aperture of the effective refractive-index difference introduced by the suspension and not by the average interparticle distance.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 62138, USA. rconroy@fas.harvard.edu
authors.forename: Richard S
authors.initials: RS
authors.lastname: Conroy
authors.forename: Brian T
authors.initials: BT
authors.lastname: Mayers
authors.forename: Dmitri V
authors.initials: DV
authors.lastname: Vezenov
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Wolfe
authors.forename: Mara G
authors.initials: MG
authors.lastname: Prentiss
authors.forename: George M
authors.initials: GM
authors.lastname: Whitesides