Terahertz surface plasmon polaritons on metal and semiconductor surfaces

We present measurements of surface plasmon polaritons (SPPs) at terahertz frequencies. SPPs are generated by coupling THz radiation into semiconductor surfaces and flat gold surfaces coated with a dielectric film. In this way, we can strongly confine SPPs to the surface, as it is required to perform sensitive spectroscopy. We also show that the measurements of the propagation of SPPs on semiconductors and on periodically structured semiconductor surfaces as a step towards plasmonic structures.