| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for high-yield manufacture of glass preform. <P>SOLUTION: In the manufacturing method for glass preform, 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 deposition step, a glass fine deposit 13 is produced in such a manner that the concentration of additives other than quartz glass is controlled to≤8 wt.% in a region to 1.7 mm in the radial direction from the inner wall face of the hollow hole in the transparent glass tube material 14 after the clarification step. In the solidification step, the temperature of the transparent glass tube material 14 is held to≥500°C in a period till the production of a solid glass base material after the completion of vapor phase etching. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
