OPTICAL FIBER TRANSMISSION LINE

摘要

PROBLEM TO BE SOLVED: To achieve improved long-distance transmission characteristics by two types of optical fibers. SOLUTION: A 5-relay span of a 6-relay span comprises a positive dispersion optical fiber 18 and a negative dispersion optical fiber 20, and the accumulation wavelength dispersion and the dispersion probe of the positive dispersion optical fiber 18 are compensated for by the negative dispersion optical fiber 20. The last 1-relay span is made of a positive dispersion optical fiber 22 made of the same optical fiber as the positive dispersion optical fiber 18. The length of each relay span is essentially the same. Average wavelength dispersion Dlocal after local dispersion compensation by the negative dispersion optical fiber 20 ranges from 1 ps/nm/km to 4 ps/nm/km, and average wavelength dispersion Davg after dispersion compensation by the positive dispersion optical fiber 22 is a positive or negative value close to zero.