Sodium-Based Cylindrical Plasmonic Waveguides in the Near-Infrared

Area of Science:

• Photonics and Nanotechnology
• Materials Science

Background:

• Subwavelength optical field confinement is crucial for compact photonic integration.
• Plasmonic devices offer strong confinement but suffer from inherent Ohmic loss.
• Sodium (Na) shows potential for lower loss in the near-infrared, but its confinement ability requires assessment.

Purpose of the Study:

• To investigate the optical properties of dielectric-coated sodium (Na) nanowires.
• To assess the field confinement and low-loss propagation capabilities of Na-based plasmonic devices.
• To compare the performance of Na with traditional plasmonic materials like silver.

Main Methods:

• Finite element calculations were employed to analyze modal fields.
• Simulations focused on dielectric-coated Na nanowires with one or two dielectric layers.
• Low-loss propagation properties were thoroughly studied.

Main Results:

• Dielectric-coated Na nanowires demonstrate lower optical loss compared to silver.
• Na exhibits stronger field confinement capabilities than silver.
• The proposed structures show significant potential for enhancing plasmonic device performance.

Conclusions:

• Sodium is a promising alternative to noble metals for plasmonic devices, offering improved performance.
• Dielectric coating effectively manages the reactivity of Na for practical applications.
• These findings pave the way for advanced subwavelength photonic devices.