Investigation into Doping of Silica Glasses with Fluorine by Modified Chemical Vapor Deposition

摘要

The equilibrium observed during modified chemical vapor deposition (MCVD) of silica glasses doped with fluorine is investigated by chemical thermodynamics.The influence of the flow rate of Freon-12 and sulfur hexafluoride on the efficiency of the incorporation of fluorine into the condensed phase is analyzed.It is revealed that,at very low flow rates of fluorinating reactants,more than 50% of fluorine can be incorporated into the glass.The refractive index and the efficiency of the conversion of SiCl_4 into the fluorine-doped silica glass are studied as functions of the vapor-gas phase composition.