| 摘要 |
PURPOSE:To obtain the title matrix freed from bubbles or crystal grains by treating, in an atmosphere of inert gas of specified partial pressure, a sintered form produced by sintering a porous glass matrix in a He atmosphere. CONSTITUTION:A burner 2 for synthesizing glass fine particles is fed with a glass material gas, combustion gas and auxiliary combustion gas to subject said glass material gas to flame hydrolysis with a flame 3 from the burner 2, and the resultant glass fine particles produced are accumulated on the tip of a rotating starting material 4 to obtain a porous glass matrix 5. Thence, this matrix 5 is heated in a He atmosphere at 1,500-1,650 deg.C into a transparently vitrified sintered form, which is then heat-treated in an atmosphere of an inert gas consisting of N2 or Ar >= 0.8 in the partial pressure at 800-1,000 deg.C for >=180min. |
