| 摘要 |
PURPOSE:To prepare a glass material of high quality efficiently in inexpensive apparatuses by the plasmatic DVD method, by generating a plasma in a glass pipe, and heating the glass pipe with a cylindrical material covering the outer periphery thereof as a heating element. CONSTITUTION:A plasma is generated in a glass pipe 1 by a plasma generator 6 while feeding a raw material gas (a raw material for glass, vapor-phase dopant and a carrier gas) into the glass pipe 1. A cylindrical material 2 is simultaneously kept in an induction heated or dielectric heated state, and the raw material gas is thermally decomposed through the generated heat of the plasma. Fine sooty glass powder which is the reaction product of the thermal decomposition is deposited on the inner periphery of the glass pipe 1 heated to a high temperature by the heating means and simultaneously vitrified and changed into a fused state with the glass pipe 1. Thus, the aimed given glass layer 7 is then formed. |
