Patent ID: 6532775
Filing Date: 2003-03-18
Classification: C03B,G02B

Abstract:
A method of manufacturing an optical fiber preform (3) comprising: forming at least one silica-based outer deposition layer (23) by depositing silica, in the presence of a plasma torch, on a primary preform (24) constituted by a bar mainly comprising silica and including a silica-based outer peripheral portion (22),the method being characterized in that the viscosity of the outer deposition layer (23) is adjusted to be substantially identical to the viscosity of the outer peripheral portion (22) of the primary preform (24) by adding to the silica in the presence of the plasma torch, over a substantial portion of the outer deposition layer (23), at least one compound being a dopant selected from the group consisting of CaF2, MgF2, AlF3, B2O3, and Al2O3.