METHOD FOR DEPOSITING A COATING LAYER ON AN OPTICAL FIBRE WHILE IT IS BEING DRAWN AND DEVICE FOR ITS IMPLEMENTATION

摘要

The invention concerns a method for depositing a coating layer on an optical fibre wile it is being drawn. The coating layer is designed to reduce the permeability of the fibre to water vapour thereby increasing its life span. The method is characterised in that it consists in decomposing a gaseous mixture of boron halide and hydrogen and/or boron halide and ammonia by means of capacitively coupled microwave plasma assisted energy supply, and it consists in carried out in the presence of a carrier gas to entrain said gaseous mixture towards a reaction medium and in activating the plasma.