| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a target rod for depositing glass fine particles on the tip according to a VAD method in order to permit stable production of large-size porous glass preform, and to provide a method for producing large-size porous glass preform using the target rod. <P>SOLUTION: The target rod 1 has a columnar shape and has at least one annular groove 2. When producing a large-size glass preform by using the target rod 1, a glass-forming raw material containing at least silicon compound is hydrolyzed by oxyhydrogen flame to produce glass fine particles and the glass fine particles are deposited on an area including the annular groove 2 of the rotating target rod 1. <P>COPYRIGHT: (C)2012,JPO&INPIT |
