Electromagnetically Coupled Resonant Face-to-Face Double-Layer Metamaterial for Highly Sensitive THz Impedance...

Area of Science:

• Metamaterials and Nanophotonics
• Terahertz (THz) Spectroscopy
• Electromagnetic Coupling

Background:

• Terahertz (THz) metamaterials offer unique electromagnetic properties.
• Enhancing the sensitivity of THz metamaterial impedance spectroscopy is crucial for advanced sensing.
• Existing methods often require precise alignment and lack high sensitivity for ultra-low concentration detection.

Purpose of the Study:

• To introduce a new electromagnetic coupling mechanism between two passive terahertz electric-LC resonator metasurfaces.
• To maximize terahertz metamaterial impedance spectroscopy sensitivity through resonance spectral red-shift (ΔF).
• To develop a double-layer metamaterial sensor for high-sensitivity dielectric detection and biosensing.

Main Methods:

• Generating a resonant optical cavity by bringing two resonant metasurfaces into face-to-face proximity under THz radiation.
• Utilizing electromagnetic coupling to enhance plasmonic interaction between THz radiation and metasurfaces.
• Investigating the critical role of optimal distance between metasurfaces for enhanced electrical field coupling.

Main Results:

• Achieved an enhanced resonance with a high Q-factor of 549 in the optimally coupled double-layer metamaterial.
• Demonstrated a high dielectric sensitivity of 2300 GHz RIU⁻¹ without major alignment requirements.
• Successfully detected inorganic and organic nanoparticles, and sugar in ultra-low concentrations, including precise blood sugar tracking.

Conclusions:

• The novel sensor architecture enables high-sensitivity THz impedance spectroscopy.
• The double-layer metamaterial sensor is effective for detecting ultra-low concentrations of various substances.
• This technology holds significant potential for advanced biosensing and dielectric detection applications.