| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a porous optical fiber rod which gives optical fibers in good productivity, and to provide a method for easily and inexpensively producing the porous rod. <P>SOLUTION: The porous optical fiber rod 18 has a clad region 17 composed of SiO<SB>2</SB>alone or of both SiO<SB>2</SB>and SiF or GeO<SB>2</SB>around a core region 14 composed of GeO<SB>2</SB>and SiO<SB>2</SB>, wherein the ratio A/B is 2.0 or below (wherein A is the bulk density of the peripheral area 15 of the core region 14, and B is the average bulk density of the area 16 except the peripheral area 15). <P>COPYRIGHT: (C)2003,JPO</p> |
