| 摘要 |
PURPOSE: To obtain a multicore fiber preform which is small in propagation loss of light by bundling and packing plural core materials into a quartz tube, then packing materials such as SiO2 into the clearances to eliminate the clearances, then allowing the tube to collapse at high temp. CONSTITUTION: Plural pieces of the core materials 2 are packed into the quartz tube 1 and, thereafter, the materials mainly composed of the SiO2 (e.g. non-doped silica fibers) or the materials having the refractive index approximate to the refractive index of quartz are packed as the packing materials 4 into the clearances between the core materials 2 and the core materials 2 and the clearances 3 between the core materials 2 and the quartz tube 1 to eliminate the clearances 3. Next, the quartz tube 1 is made to collapse at a high temp, by which the multicore fiber preform 5 consisting of the plural cores is obtd. The collapse is executed simply by heating the one side of the quartz tube 1 with a heater to seal this end, then gradually shifting the burner to the other end until the quartz tube collapses. As a result, the clearances 3 are packed with the packing material 4 and, therefore, the resultant multicore fiber preform 5 is made complete round, and the propagation loss of light is lessened. |
