| 摘要 |
PURPOSE:To efficiently obtain a optical fiber having high quality from a large preform by depositing glass fine particles on the outer periphery of a quartz rod, sintering the produced glass rod/glass fine powder deposit product, thermally melting the composite product and subsequently drawing the melted product. CONSTITUTION:(a) Upper and lower dummy bars 2, 3 are connected to the upper and lower ends of a quartz glass rod (base material), respectively, and main rods (rotational shafts) 6, pine holes 4, etc., are installed at the fitting parts of the dummy bars. respectively. A glass raw material gas, a combustion gas, a combustion-supporting gas, etc., are blown out from a burner 7 to deposit the glass fine particles produced in the flame 8 on the central part of the bar. (b) The produced composite product comprising the bars 2, 3, the matrix 1, and the glass fine particle deposit product 9 is sintered to produce (c) the transparent preform 10, while the bars 2, 3 are kept as such. Both the ends of the bars 2, 3 of the preform 10 are placed in a heating furnace, supported with the fitting parts of upper and lower fitting members 12, 13, and subsequently drawn with upper and lover drawing chucks 17, 18 under heating to produce (d) optical fiber of the preform (d). |
