REDUCTION OF HYDROXYL GROUP CONTENT FROM PREFORM FOR OPTICAL FIBER MADE BY MCVD PROCESS

摘要

Process for reducing hydroxyl-group content in preforms for optical fibres, manufactured by MCVD process, consisting of isotopic exchange between hydrogen and deuterium near the internal walls of the silica-glass supporting tube (8). The operation is carried out in two steps, first by inducing deuterium adsorption and then by termally activating the exchange reaction.