Development of fully three-dimensional wavefront matching method and its application to the design of ultrasmall Si mode converters

Fully three-dimensional wavefront matching method for waveguide discontinuity problem is newly developed. In principle, the developed method can be applied to optimize any geometries including reflection. The application for Si mode converters (TE₀-TE₁, and TE₀-TE₂) are demonstrated and ultrasmall structure with low-loss is obtained.