Abstract: A starting material for producing optical fibers contains metal halides. The refractive index of the optical fiber formed from the starting material is predeterminable by adjusting a partial pressure ratio of a halogen-containing gas mixture. The starting material is produced by mixing halogenated gases into a gas mixture with the desired partial pressure ratio, causing a chemical reaction at a first temperature of the gas mixture with at least metal to form a reaction product, the first temperature being higher than the melting temperature of the reaction product and cooling the reaction product to a second temperature that is below the melting temperature.

Abstract: A starting material for producing optical fibers contains metal halides. The refractive index of the optical fiber formed from the starting marterial is predeterminable by adjusting a composite of the molten bath. The starting material is produced by mixing halogenated gases into a gas mixture with the desired partial pressure ratio, causing a chemical reaction at a first temperature of the gas mixture with at least metal to form a reaction product, the first temperature being higher than the melting temperature of the reaction product and cooling the reaction product to a second temperature that is below the melting temperature.

Abstract: A starting material for producing optical fibers contains metal halides. The refractive index of the optical fiber formed from the starting marterial is predeterminable by adjusting a partial pressure ratio of a halogen-containing gas mixture. The starting material is produced by mixing halogenated gases into a gas mixture with the desired partial pressure ratio, causing a chemical reaction at a first temperature of the gas mixture with at least metal to form a reaction product, the first temperature being higher than the melting temperature of the reaction product and cooling the reaction product to a second temperature that is below the melting temperature.