  We experimentally demonstrate a type of waveguiding mechanism for coupled
surface-wave defect modes in a surface-wave photonic crystal. Unlike
conventional spoof surface plasmon waveguides, waveguiding of coupled
surface-wave defect modes is achieved through weak coupling between tightly
localized defect cavities in an otherwise gapped surface-wave photonic crystal,
as a classical wave analogue of tight-binding electronic wavefunctions in solid
state lattices.
