Mechanisms of optical losses in fibres with a high concentration of germanium dioxide

The mechanisms of optical losses determining the scattering of light in single-mode fibres with a high germanium-dioxide content in a core are investigated. The coefficients of the Rayleigh scattering in fibres with a high level of doping (a molar concentration of GeO₂ of up to 30 %) are measured for the first time. The investigations of the angular distribution of the intensity of light scattered from the fibre have revealed the presence of an additional, anomalous scattering of light besides the Rayleigh scattering. The nature of this phenomenon is discussed.