Broadband wave absorption in single-layered and nonstructured graphene based on far-field interaction effect.

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Terahertz (THz) wave absorption is crucial for various applications, including sensing, imaging, and communication.
• Developing efficient and broadband absorbers in the THz range remains a significant challenge.
• Graphene's unique electronic properties make it a promising material for THz devices.

Purpose of the Study:

• To design and demonstrate a novel broadband near-perfect absorber for terahertz waves.
• To investigate the absorption mechanism of the proposed graphene-based structure.
• To facilitate the fabrication and application of efficient broadband graphene absorbers.

Main Methods:

• A wave absorption design utilizing periodical arrays of dielectric bricks on a dielectric substrate.
• The substrate is coated with single-layered, nonstructured graphene and supported by a metal layer.
• Analysis of graphene plasmon resonances and far-field interactions between resonators to understand absorption mechanisms.

Main Results:

• The proposed design achieves broadband near-perfect absorption with a bandwidth of 0.82 THz.
• Absorption exceeds 90% over the demonstrated bandwidth, centered at 1.68 THz.
• The mechanism involves graphene plasmon resonances and broadened resonance linewidths due to resonator interactions.

Conclusions:

• The simple design enables broadband near-perfect absorption in the THz range.
• The study elucidates the dual contribution of graphene plasmon resonances and resonator coupling to broadband absorption.
• This work paves the way for practical applications of broadband graphene absorbers in THz technologies.