Checkerboard Helmholtz Resonator Metasurface for Dual-Mode Decoupled Dual-Band Coherent Perfect Absorption with...

Area of Science:

• Metamaterials and Plasmonics
• Terahertz (THz) Technology
• Electromagnetic Wave Manipulation

Background:

• Coherent Perfect Absorption (CPA) is crucial for advanced optical devices.
• Metasurfaces offer versatile platforms for controlling electromagnetic waves.
• Achieving dual-band and independently tunable CPA remains a challenge.

Purpose of the Study:

• To design and demonstrate a checkerboard metasurface for decoupled dual-band CPA.
• To achieve independent and continuous tuning of absorption frequencies.
• To explore the potential for stable and spectrally flexible terahertz absorbers.

Main Methods:

• Integration of interleaved Helmholtz resonator arrays with distinct geometrical parameters.
• Utilizing a planar checkerboard configuration to minimize mutual coupling.
• Employing full-wave simulations to verify absorption characteristics and resonant modes.

Main Results:

• Achieved absorption rates exceeding 99% at four distinct terahertz frequencies (2.904, 3.024, 3.788, and 3.856 THz).
• Demonstrated decoupled dual-band CPA under in-phase and anti-phase excitation.
• Showcased independent and continuous tunability of absorption bands by manipulating excitation phase differences.

Conclusions:

• The proposed metasurface offers stable and independent dual-band absorption.
• The design provides enhanced frequency stability and spectral flexibility for terahertz applications.
• This work presents a promising pathway for developing advanced terahertz coherent absorbers.