Study of surface plasmons travelling along straight and curved metal-dielectric interfaces: Experiment and theory

Terahertz surface plasmons (SPs) produced by monochromatic radiation of Novosibirsk free electron laser and travelling along straight and curved metal-dielectric interfaces have been studied experimentally. Characteristics of SPs and radiation decoupled into free space were examined with three complementary terahertz sensors (a Goley cell, a 320×240 uncooled microbolometer matrix, and a cryogenic hot electron bolometer). The terahertz electromagnetic field which arises when an SP reaches the end face of a metal slab was studied theoretically using the Sommerfeld-Malyuzhinets technique. The theoretical and experimental results are in a good agreement.