Communication at millimetre-submillimetre wavelengths using a ceramic ribbon.

Following the discovery by Kao and Hockman that ultra-low-loss optical fibres could be made from pure silica through the elimination of impurities, the ability to guide signals effectively at optical wavelengths has been assured. But there remains an important region of the spectrum--from 30 to 3,000 GHz (the millimetre-submillimetre band)--where low-loss waveguides are unknown. The main problem here in finding low-loss solids is no longer one of eliminating impurities, but is due to the presence of intrinsic vibration absorption bands.