Preparation of SiO2-B2O3 glass for PANDA optical fibre from colloidal sol-gel process

SiO₂-B₂O₃ glass for the PANDA optical fibre is prepared from the colloidal sol-gel process. The preparation of SiO₂-B₂O₃ glass is through the gellation of fumed silica dispersed in water containing boric acid. Two processes to dry the gel are examined, and freeze-drying is selected as the better drying method. The process produces a dried gel without cracks and with a uniform distribution of boron oxide concentration. The dried gel is sintered into glass