PRODUCTION OF PREFORM FOR OPTICAL FIBER

摘要

PURPOSE:An SiO2 porous parent material containing at least one selected from P2O5, GeO2 and B2O3 is sintered in the presence of a gas containing a phosphorus compound to produce polymode glass fiber with less pulse dispersion over a wide range of wave length. CONSTITUTION:By the VAD process, an SiO2 porous parent material 1 doped with P2O5 or other substances is deposited on the end of the seed rod 2. Then, the porous parent material 1 is put in the furnace core tube 3 filled with a gas containing a phosphorus compound such as He gas containing POCl3 and sintered by heating with the heater 4 to convert it into a transparent glass (preform) 5.