| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing a glass preform, which is suitable for production of an optical fiber that is reduced in transmission loss in the 1.38 μm wavelength band. <P>SOLUTION: In the method for producing the glass preform, a glass preform is produced through a fixation step, a deposition step, a drawing step, a clarification step and a solidification step, in that order. In the clarification step, a glass fine particle deposit 13 is charged into a heating furnace 22 into which an He gas and a Cl<SB POS="POST">2</SB>gas are introduced, together with a seed bar pipe 12 which is integrated with the glass fine particle deposit 13, and heated by a heater 23, thereby producing a transparent glass tube material 14. Right after production of the transparent glass tube material 14, a dry gas is introduced into the heating furnace 22, and the transparent glass tube material 14 is cooled, while controlling the humidity in the ambient atmosphere of the transparent glass tube material 14 to 0.1% or less. <P>COPYRIGHT: (C)2012,JPO&INPIT |
