| 摘要 |
The procedure for cooling an optical fibre during manufacture consists of a fast cooling stage in a zone and a slow cooling stage in a zone, in which the fibre is cooled at a faster and a slower rate than the ambient air respectively. In between the fast and slow cooling zones the fibre passes through an intermediate zone, made as small as possible, in which its temperature is between 1200-1700 degrees C for silicon glass fibres, 200-400 degrees C for fluoride glass fibres, and 150-250 degrees C for polymer-based fibres, i.e. a temperature equal to a critical value for minimal attenuation. The initial temperature of the fibre entering the fast cooling zone is equivalent to the critical temperature 250 - 350 degrees C. The instant cooling gradient compared with air cooling is less than 1 in the slow cooling zone, and the final temperature of the fibre leaving the slow cooling zone is equal to the critical temperature -50 - 950 degrees C. |
