On Optimal Conditions for Generation of Terahertz Surface Plasmon-Polaritons by the End-Fire Coupling Technique

The results of an experimental study of the generation of surface plasmon-polaritons in the terahertz range are presented. The end-fire coupling technique has been used for generation, when the beam is focused on the metal–dielectric interface. It has been found that at normal beam incidence the efficiency of plasmon-polaritons generation is maximum and the half-width of the dependence of the generation efficiency on the angle of radiation incidence in the sample plane is 6.0° ± 0.5°. It is shown that the generation efficiency has a maximum at a certain shift of the center of the incident beam relative to the metal–dielectric interface. The half-width of this maximum is 590 ± 50 μm, which is consistent with theory within the error limits.