| abstract |
Process and device for external plasma deposition on a silica bar substantially free of hydroxyl ions, optionally doped in order to modify its refractive index, by reaction on oxygen with a silicon compound, and optionally with doping compounds , in the presence of a gas plasma brought to very high temperature by induction using a high frequency generator. The bar is maintained on which the deposition of silica is carried out in a sealed enclosure separated from the ambient atmosphere, and supplied (20) with atmospheric air, which is subjected successively to filtration (31), to compression (32 ) and to refrigeration (33), to a draining of the condensed water (35), then to a final desiccation by absorption (36,38). |