Interaction of terahertz electromagnetic field with a metallic grating: Near-field zone

Abstract

We have developed a theory for the interaction of THz radiation with a sub-wavelength metallic grating. The structure of electric field of the electromagnetic waves under the metallic grating has been studied for the near-field zone. Spatial distributions of the electric field components and the electric energy density have been obtained for the wave transmitted through the grating. An effect of strong local enhancement of the electric field has been detected. Spatial dependence of polarisation of the transmitted wave has been analysed for the near-field zone.