| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for stably manufacturing a quartz glass preform through a VAD method at a yield of at least 75%, provided the quartz glass preform has a mass of≥50 kg or has a diameter of≥250 mmϕ. <P>SOLUTION: The method for manufacturing the quarts glass preform comprises a step of depositing glass fine particles on a rotating target 30, thereby growing and synthesizing a porous quartz glass body 40, provided that the glass fine particles are obtained by hydrolyzing a glass-forming raw material in oxyhydrogen flame 20 formed by a burner 10. Here, synthetic condition of the porous quartz glass body 40 is controlled so that a recessed part 42 is formed on a surface of the porous quartz glass body 40 formed on the target 30, provided that the recessed part 42 is 5-30 mm deep and is formed at a position on the porous quartz glass body 40 that nearly corresponds to a rotating axis of the target. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
