| 摘要 |
Process for the manufacture of preforms for the production of optical fibres by drawing, in which a silica deposit, optionally containing an added doping agent, is formed by successive depositions inside a silica-based tube (1), from a vapour phase containing a gaseous silicon compound, oxygen and optionally a gaseous compound of an element doping the silica, and the tube is then subjected to a shrinking operation so as to make the hollow axial region disappear. <??>The silica is then removed from the initial tube and a reloading (5) is then performed on the remaining cylinder (4) by plasma torch deposition from a gaseous phase comprising oxygen and a halogenated silica derivative. <IMAGE> |
