| 摘要 |
PURPOSE:To improve the strength and the array accuracy of a core, by placing a quartz glass packing material whose softening point is lower than that of a clad part of a preform rod, in the gap and the outside circumference of plural preform rods which have been arrayed tightly. CONSTITUTION:This multicore fiber preform consists of a core part 2 and a clad part 3, and plural preform rods 1 whose section is circular are arrayed so they are made to adhere tightly to each other. Subsequently, in a gap S' between these preform rods 1, and the outside circumference of these preform rods 1, quartz glass compound materials 4, 5 whose softening point is lower than that of the clad part 3 are provided. As for the packing materials 4, 5, for instance, a group which has mixed several mols-scores of mols P2O5 in SiO2 can be used, and also the group whose coefficient of thermal expansion is not so different from a value of the clad part 3 is suitable. |
