OPTICAL FIBER PREFORM AND ITS PRODUCTION

摘要

PURPOSE:To provide a optical fiber preform which does not entail an increase in loss depending on fiber pulling tension and the process for production of such preform. CONSTITUTION:Fluorine is codoped in porous particulate glass for core or core with glass for an inside layer clad in which the concn. density of metal oxide dopants is not uniform, by which the glass 1 for the core or the glass 2 for the inside layer clad having the uniform density distribution in the section is produced. The outside of such glass is provided with glass 3, 4 for the clad having the equal viscosity, by which the optical fiber preform having the viscosity uniform over the entire section is produced.