SPP waveguide based on the Goos–Hänchen effect

We propose and realize a single-mode surface plasmon polariton (SPP) waveguide formed by two parallel grooves on the surface of a high-quality silver film. In the waveguide, the SPP wave undergoes the Goos–Hänchen shift of up to 0.77 ⋅ λ S P P at each successive reflection, with the electric field of the SPP wave outside the metal, which significantly reduces the metal loss of the guided SPP wave. Using the waveguide, we demonstrate a complex on-chip optical circuit that includes (1) SPP plane wave excitation, (2) SPP plane wave focusing with a parabolic mirror, and (3) coupling of the focused SPP wave to the waveguide.