| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method which can manufacture a glass preform at high yield and high productivity. <P>SOLUTION: In the manufacturing method for glass preform, glass preform is produced through a fixation step, a carbon film formation step, a deposition step, a drawing step, a clarification step, and a solidification step, in that order. In the carbon film formation step, a starter rod and a burner for carbon film formation are relatively reciprocated along the axial direction of a starting rod to form a carbon film at the outer circumference of the starting rod. At this time, the flow rate of a gas around the starter rod is controlled to≤0.5 m/s. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
