Optical crossing by hybrid Si-wire/silica waveguides

We are studying the feasibility of an integrated optical circuit consisting of Si-wire waveguides and silica-based waveguides. In order to realize such a hybrid waveguide optical circuit, we proposed a simple optical crossing structure consisting of heterogeneous waveguides, and investigated the characteristics by numerical analysis and measurement. We found that the insertion loss of the waveguide crossing is low enough, and it was largely improved by making crossing with Si-taper structure.