Refractive Index Sensing Properties of Metal-Dielectric Yurt Tetramer Metasurface

Area of Science:

• Metasurface optics
• Plasmonics
• Nanophotonics

Background:

• Metal-dielectric hybrid tetramer metasurfaces are recognized for excellent refractive index sensing.
• Challenges remain in achieving high Q-factor, polarization insensitivity, multi-band tunability, and narrow linewidth simultaneously.

Purpose of the Study:

• To propose and investigate a metal-dielectric yurt tetramer metasurface for high-performance refractive index sensing.
• To overcome the limitations of existing metasurface designs for optical sensing.

Main Methods:

• Utilized the finite-difference time-domain (FDTD) method for simulating sensing properties.
• Explored resonance modes, optimized structural parameters, and analyzed environmental influences.
• Introduced structural size perturbation to excite specific resonance modes.

Main Results:

• The proposed yurt tetramer metasurface exhibits high Q-factor, wavelength tunability (visible to near-infrared), and polarization insensitivity.
• Successfully excited surface plasmon resonance and two Fano resonance modes at specific wavelengths.
• Achieved a maximum refractive index sensitivity of 500.94 nm/RIU, FOM of 491.12 RIU⁻¹, and Q-factor of 793.13.
• Obtained an ultra-narrow linewidth with a full width at half maximum (FWHM) of 1.02 nm.

Conclusions:

• The metal-dielectric yurt tetramer metasurface offers a promising platform for high-performance refractive index sensors.
• Demonstrates the potential for simultaneous achievement of key sensing parameters.
• Provides a theoretical foundation for developing next-generation optical sensing devices.