| 摘要 |
PURPOSE:To manufacture the titled preform capable of preventing the generation of bubbles, by arranging a plurality of quartz fiber filaments closely in a quartz tube, heating at a temperature below the fusion temperature, and heating and pressing the tube to effect the fusion and integration of the quartz filaments. CONSTITUTION:A plurality of surface-cleaned quartz fiber filaments are arranged closely in a quartz tube 4, put into a pressure vessel 3 furnished with the heater 1 and the heat-insulation material 2, etc., and heat-treated at a temperature below the level to start the fusion of the quartz of the quartz filaments and quartz tube 4 while removing the decomposed compound from the quartz. Pressure is applied to the outer wall of the quartz tube 4 using a pressure medium 5 such as Ar gas, etc. while heating the quartz tube at the fusion temperature of the quartz. The quartz is fused and integrated uniformly with each other to obtain the objective image guide preform capable of preventing generation of bubbles. |
