Resonantly suppressed transmission and anomalously enhanced light absorption in ultrathin metal films

TL;DR

This paper investigates how periodic modulation in ultrathin metal films causes suppressed transmission and enhanced absorption due to surface plasmon polaritons, revealing effects opposite to traditional thick film behavior.

Contribution

The study provides an analytical and numerical analysis of anomalous light diffraction phenomena in ultrathin metal films with periodic modulation, highlighting effects opposite to those in thicker films.

Findings

Suppressed transmittance in ultrathin metal films due to periodic modulation.

Enhanced light absorption and reflectivity linked to surface plasmon polaritons.

Analytical and numerical models explaining these phenomena.

Abstract

We study light diffraction in the periodically modulated ultrathin metal films both analytically and numerically. Without modulation these films are almost transparent. The periodicity results in the anomalous effects, such as suppression of the transmittance accompanied by a strong enhancement of the absorptivity and specular reflectivity, due to excitation of the surface plasmon polaritons. These phenomena are opposite to the widely known enhanced transparency of periodically modulated optically thick metal films. Our theoretical analysis can be a starting point for the experimental investigation of these intriguing phenomena.