Structures including an edge coupler and methods of fabricating a structure including an edge coupler. The structure includes an edge coupler having a longitudinal axis, a first ring resonator, and a second ring resonator. The first ring resonator has a first center point that is spaced from the longitudinal axis of the edge coupler by a first perpendicular distance. The second ring resonator has a second center point that is spaced from the longitudinal axis of the edge coupler by a second perpendicular distance.