VAD Core Deposition
SiCl4 Steam and GeCl4 Steam generated by the vapor system is oxidized reaction and hydrolyzed reaction with H2/O2 at the outlet of the burner to form fine SiO2 and GeO2 particles. The particles are axial deposition by the thermophoresis effect to prepare the soot preform.
Core Dehydration and Sintering
In 1000-1200℃ temperature conditions, the process gases such as He and Cl2 are pumped into the furnace, making the soot preform pass through the heating furnace hot area slowly thus removing the OH group and meral impurities. In 1400-1600℃ temperature conditions, pumping the He and other gases into the furnace, making the soot preform pass through the heating furnace hot area slowly which will sinter the soot preform change to transparent core.
Imported equipment can automatically analyze the optical properties of optical fiber preforms. The geometric parameters of the preform, refractive index, diameter, and concentricity can be calculated. The profile parameters also produce equivalent step-index distribution data to predict the performance of the drawn fiber and provide the necessary feedback to the preform production process.
After the prepared large-size mandrel is aligned with the tail shank, it is softened by heating at 2000-2200 ° C in a high-temperature furnace. The large-size preform is extended to a smaller size by the difference in speed between the upper and lower tail shanks.