Light wave conductors mfr. for optical fibres - by coating internal surface of tube with diffusion layer to remove impurities prior to coating when glass core layer and drawing

摘要

Preparing a light wave conductor tube to be used to produce optical fibres consists of coating the inner surface of the tube with a diffusion layer which removes the impurities from the tube surface during heat treatment. This coating is then removed and the remaining surface vapour coated with a high purity cover and core glass layer. USE/ADVANTAGE - Making optical fibre by drawing the vapour coated tube. The impurities in the internal surface is removed in considerable vol. to present a pure surface layer. This leads to lower frequency damping in the resultant fibre at relay frequencies.