| 摘要 |
PROBLEM TO BE SOLVED: To provide the advantageous production of a fluoride glass optical fiber preform. SOLUTION: This production comprises an operation for introducing clad glass 2 in a molten state into a lower part 11 of a cylindrical casting mold 1, an operation for introducing core glass 3 in a molten state into an upper part 12 of the casting mold 1, an operation for solidifying the clad glass 2 so as to completely solidify it before complete solidification of the core glass 3 concurrently with the solidification of the clad glass 2, an operation for centrifuging the casting mold 1 with a centrifuge to form an almost cylindrical hollow glass central part, then, an operation for allowing the core glass 2 in an unsolidified state to flow into the hollow glass central part to form a preform core, and thereafter, an operation for withdrawing the solidified preform thus formed from the casting mold 1 to produce the objective fluoride glass optical fiber preform. |
