All-Silicon Polarization-Insensitive Metamaterial Absorber in the Terahertz Range

Area of Science:

• Condensed Matter Physics
• Materials Science
• Electromagnetics

Background:

• Terahertz (THz) absorbers are crucial for various applications.
• Existing THz absorbers often face limitations in bandwidth, polarization dependence, or material choices.
• All-silicon metamaterials offer a promising platform for THz devices due to their low loss and fabrication compatibility.

Purpose of the Study:

• To design and numerically investigate an all-silicon metamaterial absorber.
• To achieve broadband, polarization-insensitive absorption in the terahertz regime.
• To explore the potential of silicon ring meta-atoms for efficient THz wave absorption.

Main Methods:

• Numerical simulation of a metamaterial absorber composed of square silicon rings.
• Optimization of meta-atom structure to achieve desired absorptive properties.
• Analysis of absorption spectra, polarization dependence, and angular tolerance.

Main Results:

• Achieved broadband absorptivity above 90% from 0.77 THz to 2.53 THz (106.7% relative bandwidth).
• Demonstrated polarization-insensitive absorption across the operational bandwidth.
• Exhibited large incident angle tolerance up to 60 degrees.
• Identified impedance matching and diffraction orders as key mechanisms for strong absorption.

Conclusions:

• The proposed all-silicon metamaterial absorber offers an effective solution for broadband THz absorption.
• The design exhibits excellent performance characteristics, including polarization independence and wide angular tolerance.
• This work paves the way for practical applications of metamaterial absorbers in terahertz communication and imaging.