Embodiments of the invention include an electromagnetic waveguide and methods of forming electromagnetic waveguides. In an embodiment, the electromagnetic waveguide may include a first semiconductor fin extending up from a substrate and a second semiconductor fin extending up from the substrate. The fins may be bent towards each other so that a centerline of the first semiconductor fin and a centerline of the second semiconductor fin extend from the substrate at a non-orthogonal angle. Accordingly, a cavity may be defined by the first semiconductor fin, the second semiconductor fin, and a top surface of the substrate. Embodiments of the invention may include a metallic layer and a cladding layer lining the surfaces of the cavity. Additional embodiments may include a core formed in the cavity.