Material-assisted metamaterial: a new dimension to create functional metamaterial

Area of Science:

• Materials Science
• Nanotechnology
• Optics

Background:

• Metasurfaces offer tunable optical properties.
• Controlling resonant modes is crucial for device performance.
• Phonon absorption in dielectric materials can influence optical responses.

Purpose of the Study:

• To demonstrate a high Q-value reflective metasurface.
• To suppress sidebands of resonant modes.
• To achieve low angle-dependence for sensing and emission applications.

Main Methods:

• Fabrication of a reflective metasurface using 1D gold nanorods, a silicon dioxide spacer, and a gold back reflector.
• Investigating resonant mode behavior near the phonon absorption wavelength of SiO₂.
• Characterizing the metasurface's optical performance, including Q-value and angle-dependence.

Main Results:

• A high Q-value (40) reflective metasurface was successfully demonstrated.
• Sideband suppression of the resonant mode was achieved by tuning to the SiO₂ phonon absorption.
• The metasurface exhibited low angle-dependence.

Conclusions:

• Combining structured resonance with inherent material properties enables low angle-dependent metasurfaces.
• The demonstrated metasurface is suitable for high-sensitivity sensing.
• The proposed structure can be utilized as a narrow-band thermal emitter.