GENERATING METHOD FOR GLASS SOOTTCONTAINING FLAME

摘要

PURPOSE:To generate a flame providing a uniform refractive index distribution to an optical fiber base material without deforming nozzles by setting nozzles for blowing an oxidizing gas in front of a nozzle for blowing feed gases and combustion gas and by igniting the gases in front of the nozzles in production of the material. CONSTITUTION:Dopant-contg. feed gases blown out of multitubular burner 7 are diffusion-mixed by interference in space l and mixed with an oxidizing gas such as O2 blown out of nozzle openings 10 in front of the second nozzle part. The mixed gas is ignited and burned to form glass soot-contg. flame 5. This soot is deposited on target 2. By burning the H2 and O2 after somewhat controlling the refractive index of diametral direction in space l the dopant is uniformly diffused, and distance L between the second nozzle part and the tip of the base material can be adjusted so that the outside diameter and yield of the base material are made optimal.