Tunable Broadband THz Waveband Absorbers Based On Graphene for Digital Coding.

Area of Science:

• Photonics and Metamaterials
• Terahertz Technology
• Nanotechnology

Background:

• Terahertz (THz) absorbers are crucial for various applications, but achieving flexible, tunable, and broadband absorption remains a challenge.
• Existing THz absorbers often lack programmability and efficient control mechanisms for dynamic response adjustment.

Purpose of the Study:

• To propose a novel method for coding patterns to achieve flexible control of absorption response at terahertz frequencies.
• To design and demonstrate a programmable broadband adjustable absorber with potential applications in optical equipment, information transmission, digital coding, and artificial intelligence (AI).

Main Methods:

• Fabrication of a terahertz absorber comprising an Au-graphene pattern layer, a silicon dioxide (SiO2) layer, and a metal reflective layer.
• Utilizing a concentric circle structure for broadband absorption and adjusting the graphene's Fermi level for tunable absorption.
• Implementing an encoding method based on external voltage applied to the graphene membrane for programmable absorption control, simulated using COMSOL for electric field analysis.

Main Results:

• Demonstration of a broadband absorption mechanism using a concentric circle structure.
• Achieved tunable absorption by modifying the graphene's Fermi level.
• Successfully implemented a programmable function for flexible control of terahertz absorption response via external voltage, verified through simulations.

Conclusions:

• The proposed programmable broadband adjustable absorber offers flexible and tunable terahertz absorption.
• The device's design and encoding method pave the way for advanced applications in optical equipment, information transmission, digital coding, and artificial intelligence.
• This work contributes to the development of next-generation intelligent optical devices.