DISPERSION COMPENSATION OPTICAL FIBER AND WAVELENGTH MULTIPLEX OPTICAL TRANSMISSION LINE COMPRISING DISPERSION COMPENSATION OPTICAL FIBER

摘要

A dispersion compensation optical fiber having a function of dispersion compensation of an optical fiber to which the dispersion compensation optical fiber is connected and which has a positive dispersion value in the 1.55 .mu.m wavelength band and a function of optical transmission line. The reflective index profile is a W type. When the difference of relative index between a clad (3) and a center core (1) is .DELTA.1 and that between the clad (3) and a side core (2) is .DELTA.2, the differences .DELTA.1, .DELTA.2 meet the inequalities 1.0 % .DELTA.1 1.4 % and -0.45 .DELTA.2/.DELTA.1 -a285. The ratio Ra (Ra=a/b) of the outside diameter a of the center core to the outside diameter b of the side core is in the range 0.4 Ra 0.5. The dispersion slope in the 1.55 .mu.m wavelength band is negative. The dispersion value .sigma. is in the range -50 ps/nm/km .sigma. -20ps/nm/km. The transmission loss is below 0.25 dB/km. The polarization mode dispersion value is below 0.15 ps/km1/2. The mode field diameter is above 5.5 .mu.m. A wavelength multiplex optical transmission line comprising such a dispersion compensation optical fiber is also disclosed.