Optical coupling and transport phenomena in chains of spherical dielectric microresonators with size disorder

The optical transmission properties of chains or circuits of touching polystyrene microspheres with sizes in the 3-20 mum range and a size dispersion of similar to1% are studied. The dye-doped spheres with fluorescent peaks due to whispering gallery modes were attached to one end of the chains. The effects of optical transport were detected using spatially resolved scattering spectroscopy. The attenuation was shown to be similar to3 to 4 dB per sphere for the modes with the best transport properties. A mechanism for the observed transport is suggested based on the formation of strongly coupled photonic modes in the systems of randomly detuned resonators with size disorder. It is shown that such circuits possess broad bandpass waveguiding characteristics essential for applications in integrated all-optical network devices. (C) 2004 American Institute of Physics.