| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To form an optical transmission line for broadband wavelength-division multiplex transmission using a Raman amplifier. <P>SOLUTION: Settings are made, i.e., the absolute value of dispersion in the entire wavelength band of 1,360 to 1,625 nm being 0.5 to 9 ps/nm/km, the absolute value of a dispersion slope at a 1,550 nm wavelength being≤0.03 ps/nm<SP>2</SP>/ km, the diameter of a mode field at the 1,550 nm wavelength being≤7μm, and the cutoff wavelength of a cable being≤1,360 nm. The outer circumferential side of a core 11 is covered with a clad 5 and has a 1st core layer 1 formed at the center part of an optical fiber and a 2nd core layer 2 covering the outer circumferential side of the 1st core layer 1. The specific refractive index differenceΔ1 based upon the clad 5 of the 1st core layer is set to 0.6 to 1.6% and the specific refractive index differenceΔ2 based upon the clad 5 of the 2nd core layer 2 is set minus. <P>COPYRIGHT: (C)2003,JPO</p> |
