| 摘要 |
A tubular porous silica preform is made by depositing particulate silica on a mandrel from which the preform is subsequently removed. A solid cylindrical porous silica preform is made by depositing particulate silica on an end surface of a support body. The porous preforms are then dried and the tubular preform is heated in a fluorine containing atmosphere to introduce a fluorine dopant into the silica. The rod preform is then placed inside the tubular preform and the two preforms are further dried in a chlorine atmosphere to remove residual moisture. The dual preforms are then heated in a zone sintering furnace to consolidate and collapse the porous material of the rod and tubular preforms into a transparent fused silica rod. The composite preform obtained is heated and dielectric optical waveguide drawn from it, the waveguide having a pure silica or doped silica core derived from the rod preform and a fluorine doped silica cladding derived from the tubular preform.
|
