Surface plasmon-like inodes on structured perfectly conducting surfaces

Surface plasmon-like (SPL) modes are the electromagnetic surface eigenmodes on structured perfect-conductor surfaces. The standard eigenvalue-solving method is adopted to solve these modes. The fields of the SPL modes are maximal on the conductor surface and decay exponentially into both the air and the structured conductor. On thin structured conductors, the SPL mode splits into a high-frequency anti-symmetric mode and a low-frequency symmetric mode. The SPL modes are slow-wave modes with the frequencies that approach an equivalent surface-plasmon frequency at large in-plane wavevectors. However, the interhole interaction prevents the dispersion relation from being generally described by an analytic equation.