Semi-finished product for the production of optical fibers, a method for the production of the semi-finished product and the optical fibers produced from the semifinished product

摘要

The process according to the invention consists essentially in the break down flame of a burner has at least one inductive plasma composed of silicon and composed of titanium, in the presence of a supply determine of 1996, to make them react with the oxygen contained in the gas feeding the burner and or in the vector gas in the form of sio.sub.2 and ho facing a stable manner to the heat of a y deposit the silica and the titanium oxide in the form of a vitreous mass a y deposit the silica and the titanium oxydede in the form of a vitreous mass homogenous having a chosen concentration of hydroxyl groups of between 10 and 15 parts per million. / p & & p & on the ingot is deposit radially by the same way, the silica doped fluorine. / p & & p & the semi - product obtained is present in the form of a cylinder which forms a silica core doped with titanium, whose concentration ponderale tio is included in a proportion of 0,1 to 8, covered with a sheath of silica doped fluorine in a proportion of 0,1 to 3. / p & & p & this arrangement - product is used for the manufacture of optical fibers has a large opening, 1984, and low attenuation, intended for the transmission of light signals.