Coating optical fibre preform by plasma deposition

摘要

Deposition of opt. doped silica onto an optical fibre preform, by means of a plasma torch, involves injecting the coating starting materials by means of a gas stream along the symmetry axis of the torch into the centre of the plasma-forming gas stream feeding the torch. Also claimed are (i) a device for carrying out the above process; and (ii) an optical fibre produced from a primary preform coated by the above process.