Measurement of the angular distribution of light scattered from a glass fiber optical waveguide.

This paper reports the measurement of the angular distribution of light scattered from a low-loss fiber at 1.06 microm and 0.633 microm. In addition to Rayleigh scattering, a previously undetected, near-forward scattering peak was observed. The new peak is shown to be consistent with scattering by narrow dielectric filaments aligned with the axis. The total scattering loss rate at 0.633 microm is ~10 dB/km, about (1/4) of which is due to the near-forward peak. The total scattering loss rate at 1.06 microm is ~1 dB/km.