LARGE-SIZED QUARTZ GLASS REFORM

摘要

PROBLEM TO BE SOLVED: To provide a large-size quartz glass preform of high accuracy that can attain the mass production of optical fibers of high quality at low cost. SOLUTION: A high-purity natural quartz glass tube or a synthetic quartz glass tube having the outer diameter of 50-300 mm, the ratio of the outer diameter (Do) to the inner diameter (Di) of 1.1-7, the wall thickness of >=10 mm and the wall thickness error of <=2% and the inner surface roughness of <=20μm and the core glass rod for optical fiber are integrated by fusing and the refractive index of the high-purity natural quartz glass tube or the synthetic quartz glass tube is adjusted to <=0.02% to the designed value. In addition, the difference in the refractive index is <=±0.01 on the boundary between the high-purity natural quartz glass tube or the synthetic quartz glass tube and the core glass rod for optical fiber.