| 摘要 |
PURPOSE:To obtain the optical communication cable of low transmission losses and superior band characteristics by so forming the optical fibers that the magnitude relations of refractive indices are core>clad layer>intermediate layer and that the difference in refractive index between the core and intermediate layer is 0.4% to 1.0%. CONSTITUTION:The magnitude relations of refractive indices are made core> clad layer>intermediate layer and further the refractive index difference between the core andintermediate layer is set at 0.4 to 1.0%. This numerical value indicates per cent of the difference of the relative refractive indices with the refractive index of the core as a reference. If the difference in the refractive index between the core and intermediate layer is smaller than 0.4%, stress resistance is poor and if twists are added to this, the transmission losses are considerable. When the difference in the refractive index between the core and intermediate layer exceeds 1.0%, the wide band characteristics of communication are impaired. Hence, if the difference in the refractive index between the core and intermediate layer is set at 0.4 to 1.0%, the cable of low transmission losses and superior wide band characteristics may be obtained even when the optical fibers are made to the cable. |
