| 摘要 |
PURPOSE:To produce an optical fiber with plural clads around the core while preventing impurities from entering the core and keeping the core uniform in diameter. CONSTITUTION:Glass for a core is spun to form a fiber 3 for a core and this fiber 3 is successively introduced into crucibles 5, 7 for cladding contg. molten glass 4 and glass 8 for clads. After cladding with the glass 4 and glass 8, the fiber 3 is drawn out of the outlet nozzles of the crucibles 5, 7. |
