| 摘要 |
PURPOSE:To obtain an optical fiber superior in aperture efficiency, environment resistance, strength, cost, etc., by forming a core made of multicomponent type glasses, and the surrounding glass coat layer made of a quartz type glass. CONSTITUTION:An optical fiber 1 is composed of a core 2 made of multicomponent glasses and a glass clad layer 3 made of a quartz type glass. As shown in the figure, the X axis is the radial direction of the optical fiber and the Y axis is the refractive index, and that of the core 2 and that of the clad 3 are shown. A preformed rod is prepared by sealing one end of a quartz tube of 12mm. outside diameter and 8mm. inside diameter having a thermal expansion coefft. of 5X10<-7> cm/cm deg.C, and filling the inside of the tube with a molten borosilicate glass having 830 deg.C softening point, and a thermal expansion coefft. of 32X10<-7>cm/cm deg.C, and 1.473 refractive index. |
