Prepared by the dehydration and de optical fiber preform manufacturing method using a modified chemical vapor deposition method comprising the chlorine process and this way the optical fiber

摘要

The present invention relates to an optical fiber prepared by the dehydration and de optical fiber preform manufacturing method using a modified chemical vapor deposition method including a chlorine process and a method. Optical fiber preform manufacturing method according to the invention, to form a soot layer in the gap to the inner wall of the deposition tube with the soot produced gas and the oxygen gas introduced into the deposition tube rotating on soot sintering temperature or lower; In that step, while maintaining the pore dehydration gas into the deposited tube to remove the hydroxyl groups present in the soot layer; In that step, while maintaining the air gap to de-chlorine gas into the deposited tube to remove the chlorine impurity present in the soot layer; And it characterized in that the progress of the soot generation by varying the gas composition in accordance with the refractive index profile, the process comprising the repeated; and the evaporation tube is heated to a temperature above the sintering temperature of the soot phase sintering of the soot layer. ; Optical fiber, dehydration, dechlorinated, the preform