A high-performance terahertz absorber based on synthetic-patterned vanadium dioxide metamaterials

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Terahertz (THz) absorbers are crucial for applications like sensing and communication.
• Developing absorbers with tunable and broadband characteristics remains a significant challenge.

Purpose of the Study:

• To design and investigate a novel terahertz absorber utilizing vanadium dioxide (VO2) with tunable and ultra-broadband absorption properties.
• To explore the potential of VO2's phase transition for dynamic control of terahertz absorption.

Main Methods:

• A multi-layered absorber structure was designed, incorporating synthetic VO2 patterns, a dielectric layer, and a metal reflector.
• The absorber's performance was analyzed using wave interference theory, impedance matching theory, and electric field analysis.
• The tunable absorption was achieved by modulating the conductivity of VO2 through its phase transition.

Main Results:

• The absorber exhibits near-total reflection in the insulating state of VO2.
• In the metallic state, the absorber achieves over 90% absorptance across a 7.7 THz bandwidth (5.36-13.06 THz).
• Absorbance is dynamically tunable from 4.31% to 100% by adjusting VO2 conductivity.

Conclusions:

• The designed VO2-based terahertz absorber offers significant improvements in absorption bandwidth and tunability.
• The absorber's simple structure, polarization insensitivity, and flexible incident angle make it highly practical.
• This tunable ultra-broadband terahertz absorber shows promise for photochemical energy absorption, thermal emitters, and stealth devices.