Single-mode graphene-coated nanowire plasmonic waveguide.

Area of Science:

• Nanophotonics
• Plasmonics
• Materials Science

Background:

• Surface plasmon waveguides are crucial for nanoscale optical circuits.
• Existing waveguides face limitations in tunability and miniaturization.

Purpose of the Study:

• To propose and analyze a novel single-mode graphene-coated nanowire surface plasmon waveguide.
• To demonstrate the tunability of waveguide performance via graphene's Fermi level.

Main Methods:

• Derivation of the single-mode condition using an analytic model.
• Numerical simulations to confirm modal cutoff wavelengths.
• Generation of a mode number diagram in wavelength-radius space.

Main Results:

• The proposed waveguide supports single-mode operation.
• Analytic model and numerical simulations show good agreement.
• Flexible tuning of waveguide performance by altering graphene's Fermi level is demonstrated.

Conclusions:

• The graphene-coated nanowire waveguide offers a promising platform for tunable nanophotonic devices.
• The study provides a design framework for future plasmonic nanocircuits.