Diagonal directional coupler elevator

Abstract

A waveguide coupler includes a first waveguide layer including a first waveguide, a second waveguide layer including a second waveguide optically coupled to the first waveguide, and a dielectric layer between the first waveguide layer and the second waveguide layer in a first direction (e.g., vertical direction). A distance between the first waveguide and second waveguide in a second direction (e.g., a horizontal direction) that is perpendicular to the first direction is greater than zero, and has different values at two or more different sections of the waveguide coupler along a third direction (e.g., the light propagation direction).

Dependencies are inferred from the claim text.