Enhanced terahertz transmission through a periodic array of tapered rectangular apertures

TL;DR

This paper numerically investigates how tapered rectangular apertures in a metal film enhance terahertz transmission by concentrating fields and exploiting plasmonic effects, showing significant improvements over non-tapered apertures.

Contribution

It introduces a novel design of tapered apertures that significantly increase terahertz transmission, validated through numerical simulations and theoretical comparison.

Findings

Tapered apertures show higher transmission than non-tapered ones.

Transmission peaks align with periodicity-induced plasmonic modes.

Numerical results are consistent with theoretical predictions.

Abstract

We numerically analyse extraordinary terahertz transmission properties of an array of rectangular shaped apertures perforated periodically on a thin metal film. The apertures are tapered at different angles to achieve higher field concentration at the tapered end. The periodic sub-wavelength scale apertures ensure plasmonic behaviour giving rise to the enhanced transmission of a specific frequency mode decided by the periodicity. We compare results of transmission with the rectangular shaped apertures of same parameters and observe a significant increase in the transmission for the tapered case. We have compared results of our numerical simulations with theory and have found them consistent.