Abstract: The present invention relates to an optical fiber having a large positive dispersion in a wavelength band of 1.55 &mgr;m in order to compensate for a negative dispersion inherent in an NZ-DSF in the wavelength band of 1.55 &mgr;m. This optical fiber comprises a depressed cladding structure constituted by a core region; an inner cladding, provided on the outer periphery of the core region, having a lower refractive index; and an outer cladding having a higher refractive index. In this optical fiber, the relative refractive index difference of the core region with respect to the outer cladding is 0.30% or more but 0.50% or less, and the relative refractive index difference of the inner cladding with respect to the outer cladding is −0.50% or more but −0.02% or less. Also, the optical fiber has a dispersion greater than 18 ps/nm/km at a wavelength of 1.55 &mgr;m, and an effective area of 70 &mgr;m2 or more at the wavelength of 1.55 &mgr;m.

Abstract: There is disclosed a dispersion compensator for compensating for a chromatic dispersion and dispersion slope of an optical fiber transmission line, the dispersion compensator comprising a plurality of dispersion-compensating optical fibers connected to each other, the dispersion-compensating optical fibers each having a dispersion slope compensation ratio of at least 60% with respect to the optical fiber transmission line at a predetermined wavelength, one of said plurality of dispersion-compensating optical fibers having a dispersion slope compensation ratio of at least 80%, another of said plurality of dispersion-compensating optical fibers having a dispersion slope compensation ratio within the range of 60% to 100%.

Abstract: The present invention relates to an optical fiber having a large positive dispersion in a wavelength band of 1.55 &mgr;m in order to compensate for a negative dispersion inherent in an NZ-DSF in the wavelength band of 1.55 &mgr;m. This optical fiber comprises a depressed cladding structure constituted by a core region; an inner cladding, disposed at the outer periphery of the core region, having a lower refractive index; and an outer cladding having a higher refractive index. In this optical fiber, the relative refractive index difference of the core region with respect to the outer cladding is at least 0.30% but not greater than 0.50%, and the relative refractive index difference of the inner cladding with respect to the outer cladding is at least −0.50% but not greater than −0.02%. Also, the optical fiber has a dispersion greater than 18 ps/nm/km at a wavelength of 1.55 &mgr;m, and an effective cross-sectional area Aeff of at least 70 &mgr;m2 at the wavelength of 1.55 &mgr;m.

Abstract: The present invention relates to an optical fiber having a large positive dispersion in a wavelength band of 1.55 &mgr;m in order to compensate for a negative dispersion inherent in an NZ-DSF in the wavelength band of 1.55 &mgr;m. This optical fiber comprises a depressed cladding structure constituted by a core region; an inner cladding, disposed at the outer periphery of the core region, having a lower refractive index; and an outer cladding having a higher refractive index. In this optical fiber, the relative refractive index difference of the core region with respect to the outer cladding is at least 0.30% but not greater than 0.50%, and the relative refractive index difference of the inner cladding with respect to the outer cladding is at least −0.50% but not greater than −0.02%. Also, the optical fiber has a dispersion greater than 18 ps/nm/km at a wavelength of 1.55 &mgr;m, and an effective cross-sectional area Aeff of at least 70 &mgr;m2 at the wavelength of 1.55 &mgr;m.

Abstract: The present invention relates to an optical fiber having a large positive dispersion in a wavelength band of 1.55 &mgr;m in order to compensate for a negative dispersion inherent in an NZ-DSF in the wavelength band of 1.55 &mgr;m. This optical fiber comprises a depressed cladding structure constituted by a core region; an inner cladding, disposed at the outer periphery of the core region, having a lower refractive index; and an outer cladding having a higher refractive index. In this optical fiber, the relative refractive index difference of the core region with respect to the outer cladding is at least 0.30% but not greater than 0.50%, and the relative refractive index difference of the inner cladding with respect to the outer cladding is at least −0.50% but not greater than −0.02%. Also, the optical fiber has a dispersion greater than 18 ps/nm/km at a wavelength of 1.55 &mgr;m, and an effective cross-sectional area Aeff of at least 70 &mgr;m2 at the wavelength of 1.55 &mgr;m.

Abstract: There is disclosed a dispersion compensator for compensating for a chromatic dispersion and dispersion slope of an optical fiber transmission line, the dispersion compensator comprising a plurality of dispersion-compensating optical fibers connected to each other, the dispersion-compensating optical fibers each having a dispersion slope compensation ratio of at least 60% with respect to the optical fiber transmission line at a predetermined wavelength, one of said plurality of dispersion-compensating optical fibers having a dispersion slope compensation ratio of at least 80%, another of said plurality of dispersion-compensating optical fibers having a dispersion slope compensation ratio within the range of 60% to 100%.