Vertically coupled glass microring resonator channel dropping filters

Abstract
Air-clad glass microring resonators vertically coupled to buried channel waveguides are experimentally investigated. Ring radii of 10 /spl mu/m, and channel drop bandwidths of 5 nm are reported. Vertical coupling eliminates the need for the etching of fine features, and relaxes the alignment of the resonator with respect to the input and output bus waveguides.