Photonics structures including a slotted waveguide and methods of fabricating such photonics structures. The photonics structure includes a slotted waveguide having a first waveguide core and a second waveguide core laterally positioned adjacent to the first waveguide core. The first waveguide core is separated from the second waveguide core by a slot. The photonics structure further includes a metamaterial structure having a plurality of elements separated by a plurality of gaps and a dielectric material in the plurality of gaps. The metamaterial structure and the slot of the slotted waveguide are positioned with an overlapping arrangement.