Patent ID: 6879762

Claim:
An optical transmission line comprising a positive dispersion optical fiber having a positive dispersion at a wavelength in 1.55 μm band and a negative dispersion ooptical fiber connected to said positive dispersion optical fiber and having a negative dispersion at the wavelength in 1.55 μm band, wherein said positive dispersion optical fiber has a transmission loss not larger than 0.25 dB/km at a wavelength of 1.55 μm and an effective core area not smaller than 60 μm 2 at the wavelength of 1.55 μm, said negative dispersion optical fiber has the transmission loss not larger than 0.30 dB/km and the effective core area not smaller than 30 μm 2 at the wavelength of 1.55 μm and said optical transmission line having a length L of 30 km to 150 km, an absolute value of a dispersion not smaller than 8 ps/nm/km at the wavelength of 1.55 μm at every point of the optical transmission line, a maximum accumulated dispersion not larger than 7.5×L (ps/nm) at the wavelength of 1.55 μm, and an average dispersion for an entire optical transmission line of −5 to +5 ps/nm/km at the wavelength of 1.55 μm.