| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a glass fine deposit rapidly, to which Ge is added by a VAD process and which has GI type refractive index distribution while controlling the refractive index distribution. <P>SOLUTION: In the VAD process, when a gas flow rate at a port for introducing most quantity of raw materials for glass by using the multiplex tube burner as a burner for compositing a fine glass particle is V<SB>1</SB>, and when the gas flow rate at a port nearest to the above port among ports for introducing a flammable gas and other than the above port is V<SB>2</SB>, the GI type fine glass particle deposit containing Ge is formed by flowing each gas so that V<SB>1</SB>and V<SB>2</SB>satisfy 2.0≤V<SB>1</SB>/V<SB>2</SB>≤2.5. By thus setting the flow rates within the limits, SiO<SB>2</SB>is synthesized with a yield of 70% or more and at high speed, and the refractive index distribution is satisfactorily controlled. <P>COPYRIGHT: (C)2003,JPO</p> |
