Azimuthally polarized surface plasmons as effective terahertz waveguides.

Area of Science:

• Physics
• Materials Science
• Electrical Engineering

Background:

• Metal wires have recently demonstrated effectiveness in guiding terahertz (THz) radiation.
• The high relative permittivity of metals in the THz spectral region is a key factor in this phenomenon.

Purpose of the Study:

• To analyze the properties of metal wire waveguides for terahertz radiation.
• To explain experimental observations of waveguiding in metal wires.
• To investigate the underlying physical mechanisms and material choices for optimal performance.

Main Methods:

• Theoretical analysis of wave propagation along metal wires in the terahertz spectrum.
• Investigation of surface plasmon polariton modes.
• Calculation of attenuation coefficients for different metal types and geometries.

Main Results:

• Waveguiding is attributed to the propagation of azimuthally polarized surface plasmons along the metal wire.
• The choice of metal and wire radius significantly impacts waveguiding properties.
• A copper wire with a 0.45 mm radius exhibits an attenuation coefficient below 2x10^-3 cm^-1 across the 0.1-1 THz range.

Conclusions:

• Metal wires, particularly copper, are effective waveguides for terahertz radiation.
• Surface plasmon propagation is the dominant mechanism for terahertz waveguiding in these structures.
• The demonstrated low attenuation suggests practical applications for terahertz transmission using metal wires.