| 摘要 |
PURPOSE:To obtain a silica core single mode optical fiber of low loss by forming a single mode optical fiber having a core and the 1st-3rd clads in such a way as to satisfy prescribed conditions. CONSTITUTION:The core 21 and the 3rd clad 24 of a single mode optical fiber having the core 21 and the 1st-3rd clads 22-24 consist of high purity silica and satisfy the following conditions: n1>n3>n2, (n1-n2)>=2(n1-n2) and 0< delta1< 1, 3.5<=delta2<6, where n1, n2, n3 are the refractive indices of the core 21, the 1st clad 22 and the 2nd clad 23, respectively, delta1T, delta2T are respectively the thickness of the clad 22 and the total min. thickness of the clad 22 and the clad 23 when T is designated as the radius of the core 21. The silica core single mode optical fiber of low loss is thus obtd. |
