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.
© 2005 Optical Society of America
Richard S. Conroy, Brian T. Mayers, Dmitri V. Vezenov, Daniel B. Wolfe, Mara G. Prentiss, and George M. Whitesides, "Optical waveguiding in suspensions of dielectric particles," Appl. Opt. 44, 7853-7857 (2005)