Waveguide transition and its process of fabrication.

摘要

An optical buried waveguide (2) of thickness Wg and width tg is formed in a substrate. The buried waveguide has a transition zone with an enlarged arc of length lt expanding according to an adiabatic expansion zone to a wider width wt. The second ridged optical guide (3) is etched on the substrate surface. The ridge guide covers the surface of the substrate at the narrow buried optical guide end. Over the transition the guide narrows to a width Wr. The structure allows optical mode coupling.