| 摘要 |
PURPOSE:To provide a method capable of obtaining a quartz glass preform free from residual gas bubbles and excellent in the optical characteristics and mechanical characteristics. CONSTITUTION:A porous glass precursor layer 2 is formed on the outer circumferential surface of a glass body 1, and further a porous glass layer 4 is formed on the outer circumferential surface of the porous glass precursor layer 2 or on the circumferential surface of an opaque glass layer 3 formed by the thermal treatment of the layer 2. The objective quartz glass preform can thereby be produced, because the porous glass precursor layer 2 formed on the outer circumferential surface of the glass body 1 or on the opaque glass layer 3 produced by thermally treating the precursor layer 2 exhibits good adhesion to both of the glass body 1 and the porous glass layer 4. |
