Different mechanisms for efficient optical transmission through bilayered subwavelength patterned metal films

TL;DR

This paper investigates various mechanisms enabling efficient optical transmission through bilayered subwavelength patterned metal films, highlighting the roles of tunneling, resonances, and localized plasmon polaritons through numerical simulations.

Contribution

It provides a comprehensive numerical analysis of multiple physical mechanisms affecting light transmission in bilayered metal films with subwavelength patterns, including plasmonic interactions.

Findings

Multiple transmission peaks are identified and attributed to different physical mechanisms.

Localized plasmon polaritons significantly influence tunneling and energy transfer.

Interactions between plasmon polaritons on different films create additional transmission channels.

Abstract

Light transmission through bilayered thin metal films perforated with subwavelength hole arrays are numerically studied based on a full-vector finite-difference time-domain approach. A variety of transmission peaks originating from different physical mechanisms are observed. In addition to the direct tunnelling and Fabry-P\`{e}rot resonances, generally possessed by idealized bilayered dielectric slabs, the near-field localized plasmon polaritons also play important roles. They not only influence the direct tunnelling in a destructive or constructive way, the interactions between these localized plasmon polaritons on different metal films also result in additional channels which transfer optical energy effectively.