Communication at millimetre-submillimetre wavelengths using a ceramic ribbon

Area of Science:

• Materials Science
• Waveguide Technology
• Terahertz Spectroscopy

Background:

• Ultra-low-loss optical fibers are established for optical wavelengths.
• A significant spectral gap exists in the 30–3,000 GHz (millimetre-submillimetre) band due to material limitations.
• Intrinsic vibration absorption and high skin-depth losses preclude conventional low-loss waveguides in this band.

Purpose of the Study:

• To overcome the limitations of existing materials and waveguide geometries for low-loss signal transmission in the millimetre-submillimetre spectrum.
• To demonstrate a novel waveguide design capable of achieving significantly reduced attenuation in this frequency range.

Main Methods:

• Fabrication of a ribbon-like waveguide structure with a 10:1 aspect ratio.
• Utilized ceramic alumina (Coors' 998 Alumina) as the waveguide material.
• Characterized the attenuation factor of the designed waveguide in the millimetre-submillimetre band.

Main Results:

• Achieved an attenuation factor of less than 10 dB km⁻¹ in the millimetre-submillimetre band.
• The ribbon-like ceramic alumina waveguide demonstrated over 100 times lower attenuation compared to typical circular dielectric rod waveguides.
• The demonstrated performance is sufficient for immediate practical applications.

Conclusions:

• A combination of specific material choice (ceramic alumina) and waveguide geometry (ribbon-like structure) effectively circumvents intrinsic material limitations for low-loss millimetre-submillimetre wave propagation.
• This novel waveguide design opens possibilities for new applications in the previously challenging millimetre-submillimetre spectral region.