Design of Metamaterial Surfaces with Broad-band Absorbance

TL;DR

This paper introduces a simple design method for creating ultra-thin plasmonic absorbers with nearly perfect broad-band absorbance by combining sub-units of different sizes and modeling their response with a series circuit approach.

Contribution

It presents a novel design paradigm and a theoretical model for broad-band plasmonic absorbers using sub-unit size variation and circuit modeling.

Findings

Achieves nearly 100% absorbance at multiple frequencies

Demonstrates high absorbance over a broad frequency range

Validates the circuit model for short surface plasmon propagation lengths

Abstract

A simple design paradigm for making broad-band ultra-thin plasmonic absorbers is introduced. The absorber's unit cell is composed of sub-units of various sizes, resulting in nearly 100% absorbance at multiple adjacent frequencies and high absorbance over a broad frequency range. A simple theoretical model for designing broad-band absorbers is presented. It uses a single-resonance model to describe the optical response of each sub-unit and employs the series circuit model to predict the overall response. Validity of the circuit model relies on short propagation lengths of the surface plasmons.