A Perfect Absorber Based on Similar Fabry-Perot Four-Band in the Visible Range.

Pinghui Wu,Li Lv,Bin Liu,Yijun Tang,Congfen Zhang

doi:10.3390/nano10030488

Abstract

A simple metamaterial absorber is proposed to achieve near-perfect absorption in visible and near-infrared wavelengths. The absorber is composed of metal-dielectric-metal (MIM) three-layer structure. The materials of these three-layer structures are Au, SiO2, and Au. The top metal structure of the absorber is composed of hollow three-dimensional metal rings regularly arranged periodically. The results show that the high absorption efficiency at a specific wavelength is mainly due to the resonance of the Fabry–Perot effect (FP) in the intermediate layer of the dielectric medium, resulting in the resonance light being trapped in the middle layer, thus improving the absorption efficiency. The almost perfect multiband absorption, which is independent of polarization angle and insensitivity of incident angle, lends the absorber great application prospects for filtering and optoelectronics.

Highlights

The dielectric constant of metal materials is less than zero in visible and infrared bands, which is contrary to the symbol of the dielectric constant
It has been found that the combination of metal and dielectric materials can transform the incident electromagnetic wave into surface plasmon polariton (SPP), to enhance the light regulation ability of materials at the nanoscale [6]
A local electromagnetic field is generated in the medium, which enhances the absorption of electromagnetic waves by the metal

Summary

Introduction

The dielectric constant of metal materials is less than zero in visible and infrared bands, which is contrary to the symbol of the dielectric constant. With the appearance of metal-dielectric micro/nano structures, we can realize enhanced resonance absorption of electromagnetic waves in specific wavebands using surface iso-excimer resonance or other resonance effects. Among these structures, metal-dielectric-metal-based multilayer structures have natural magnetic resonance properties. The same principle can be used in optical frequencies to design an anti-reflective film on a camera lens or glass For another example, a pyramid-shaped structure can increase the number of reflections and scatter in the structure by matching the impedance of free space, increasing the absorption efficiency [16]. By changing the structure size of the absorber and the metal structure on the surface, the absorber can achieve a broader tolerance range for polarization and incidence angle, which has potential for application in filtering and optoelectronics

Physical Design

Results and Discussions

The study of different polarization patterns