Patent ID: 6865326

Claim:
An optical transmission line comprising: an optical transmission fiber having a chromatic dispersion of +4 to +10 ps·nm −1 ·km −1 and a dispersion slope of 0 to +0.04 ps·nm −2 ·km −1 at the 1550 nm wavelength and installed in a relay section; and a module made of a dispersion compensating optical fiber having a chromatic dispersion of −40 ps·nm −1 ·km −1 or less and a dispersion slope of −0.10 ps·nm −2 ·km −1 or less at the 1550 nm wavelength, wherein said dispersion compensating optical fiber has a lenght that is sufficient to substantially compensate the chromatic dispersion of said optical transmission fiber at the 1550 nm wavelenght and loss of said module at the 1550 nm wavelength is not more than 0.035 dB per unit kilometer of said optical transmission fiber.