Bloch states in light transport through a perforated metal

TL;DR

This paper analyzes light transmission through perforated metals, deriving analytical expressions for transmission coefficients and exploring effects of metal fraction and surface plasmons in various configurations.

Contribution

It provides new analytical formulas for light transmission in perforated metals and investigates the impact of metal fraction and surface plasmons on transmission behavior.

Findings

Existence of a wavelength-independent minimum in transmission at low metal fractions

Transmission increases monotonically with metal fraction beyond the minimum

Surface plasmons play a significant role in light transport through perforated metals

Abstract

Light transport in a metal with two-dimensional hole arrays is considered. Analytical expression for a transmission coefficient in periodic, isolated and disordered cases are derived, assuming the existence of waveguide modes transverse tunneling in two-dimensional plane perpendicular to traveling direction of light. The one dimensional case of periodic holes, due to its simplicity, is investigated in detail. In the dilute metal regime, when metal fraction is small, our numerical study of the transmission coefficient of central diffracted wave indicates the existence of a minimum which is completely independent of an incident wavelength. Further increasing of metal fraction leads to the unusual monotonic increasing of central diffracted wave transmission. The role of the surface plasmons is discussed.