Loss-Less Multilevel Crossing of Busline Waveguide in Vertically Coupled Microring Resonator Filter

摘要

To eliminate the sattering loss at the crossing points of cross grid busline waveguides, a multilevel crossing structure of busline waveguide was introduced into the vertically coupled microring resonator filter. The top surface of each buried waveguide was perfectly planarized by a new fabrication process and clear filter responses were observed for a single ring and a series coupled double ring resonator with multilevel crossing busline waveguides.