Patent attributes
A device includes a first directional coupler and a second directional coupler. A first arched waveguide forms a first curved optical path between a first output port of the first directional coupler and a first input port of the second directional coupler. The first arched waveguide has an angle of curvature and a radius of curvature. A second arched waveguide has the angle of curvature and the radius of curvature. The first arched waveguide and the second arched waveguide each have a concavity oriented in the same direction. A first straight waveguide is coupled to a second output port of the first directional coupler and a first end of the second arched waveguide. A second straight waveguide is coupled to a second end of the second arched waveguide and a second input port of the second directional coupler.