METHOD FOR TREATING AN OPTICAL FIBER PREFORM WITH DEUTERIUM

摘要

A method of forming an optical fiber preform that comprises depositing a layer of silica soot onto an outer surface of a consolidated glass preform to form a composite preform having an inner consolidated glass portion and an outer silica soot portion, and exposing the composite preform to an atmosphere containing a concentration of a deuterium compound for a time and at a temperature sufficient to cause the deuterium compound to penetrate the consolidated glass portion without pervading the entire glass portion. Preferably, the deuterium compound penetrates the glass portion to a desired depth, e.g. to the point RD1, indicated in figure 6, at a desired radial distance from the centre axis of the core.