Process Research of Amorphous SiO<sub>2</sub> for Optical Fiber Preform by Sol-Gel

Abstract

To prepare the amorphous SiO2 optical fiber preform which has lower attenuation, we selected TEOS as raw material, H2O as menstruum, HCl as catalyst, CH3NO as anti-cracking agent, prepared the mandrel material of SiO2 optical fiber preform by sol-gel method. The XRD, SEM, FT-IR and TG were used to study the characteristic of the samples. The results show that the TEOS and H2O can be uniformly mixed with vigorous stirring and water increasing. The hydrolysis rate of TEOS will increase with the increasing HCl volume. The transparency will decrease when the HCl reaches a fixed value. The CH3NO can play a role of anti-cracking agent, it also can affect the transparency if it is more. The optimal capability parameter TEOS: H2O: HCl: CH3NO = 1: 25: 0.5: 0.1. The optimal heat treatment process was determined by TG and FT-IR as follows: the temperature was risen slowly to 170°C and 300 °C for 1h, and then reluxed at 900°C for 2h.