Beam Collimation Using an Anisotropic Metamaterial Slab without Any Nanometer-sized Aperture

TL;DR

This paper demonstrates a simple, cost-effective anisotropic metamaterial slab with a top grating can achieve plasmonic beam collimation similar to complex nanostructures, enabling practical applications.

Contribution

It introduces a novel AMM slab design with a top grating for beam collimation, avoiding nanometer-scale apertures and complex fabrication.

Findings

AMM slab achieves beam collimation comparable to bull's eye structures

Effective medium theory and FEM analyze the structure's performance

Cost-effective and simpler architecture for practical use

Abstract

Plasmonic beam collimation effect has been thoroughly investigated based on the well-known nanometer-scale bull's eye structure formed by complex and high-cost fabrication processes. In this work, we report our effort for attaining beam collimation using an anisotropic metamaterial (AMM) slab that consists of a stack of alternating metal/dielectric layers and an integrated top metal grating. The results show that AMM slab allows creating the beam collimation effect similar to that of the bull's eye structure, an enabling technology for practical application due to its simple architecture and cost benefits. The excitation of surface plasmons at the AMM/air interface is derived. The structure of the AMM slab and its impact on beaming performance were analyzed using the effective medium theory and Finite Element Method.