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

TL;DR

This paper presents a theoretical study of how terahertz radiation interacts with a sub-wavelength metallic grating, revealing electric field distributions, energy density, and local field enhancement effects in the near-field zone.

Contribution

The authors developed a new theoretical model describing near-field electric field distributions and polarization effects of THz waves interacting with metallic gratings.

Findings

Detected strong local electric field enhancement.

Mapped spatial electric field distributions.

Analyzed polarization variations in the near-field zone.

Abstract

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