| 摘要 |
PURPOSE:In a sintering process which is carried out succeeding piling a medium contining a metal oxide for adjusting a refractive index, to make the metal oxide contained in glass into a given concentration distribution, by regulating a gas component of sintering atmosphere. CONSTITUTION:A glass medium consisting essentially of SiO2 and a metal oxide for adjusting a refractiv index is piled on a rotary body. The aggregate of the glass fine particles are sintered in an inert gas atmosphere containing a halogen compound. The blending ratio of halogen is varied corresponding with rate of temperature rise. The volatilization of the metal oxide during sintering is controlled, and glass having a concentration distribution exhibiting high concentration at the central part and low concentration at the peripheral part is obtained. |
