Surface plasmon polariton generation on metal surface: From nano-optical to terahertz frequency regime

We investigate surface wave generation by a single slit, both in nano-optical and in terahertz regimes. The wave-front in optical regime separates itself into forward propagating wave and surface-bound 90-degree diffracted wave; while, no such clear separation of modes is not observed in terahertz regime. Excitation wavelength dependency is systematically studied.