Abstract: Disclosed is an optical fiber having a desired dispersion value to sufficiently suppress a non-linearity phenomenon, that is, a four-wave mixing phenomenon, occurring at a channel spacing of 50 GHz while minimizing the expense consumed for a compensation for dispersion. The optical fiber satisfies optical characteristics defined by a dispersion value of 7 to 10 ps/nm-km at a wavelength of 1,550 nm, a zero dispersion wavelength of 1,450 nm or less, and a cut-off wavelength of 1,250 nm or less. The optical fiber includes a core having a desired diameter (d1) and a desired refractive index (n1), the cladding surrounding the core and having a refractive index (ncl) less than the (n1), of the core (ncl<n1) or (n2) less than the outer cladding (n2<ncl). The (n2) of the inner cladding may also be less than the (n1) of the core and more than the (ncl) of the outer cladding.

Abstract: The present invention is related to a dispersion-shifted optical fiber for use in a wavelength division multiplexing system, which comprises a core, an inner clad, and a silica clad, wherein the optical fiber has a relatively low dispersion at a wavelength of 1550 nm, an effective area of 60 &mgr;m2 and small bending loss. The core consists of a first and a second core, wherein the core has a refractive index distribution. The inner clad consists of a first inner clad having a refractive index smaller than that of the second core and a second inner clad having a refractive index smaller than that of the second inner clad. A silica clad surrounds the inner clad and has a refractive index smaller than that of the second inner clad.

Abstract: Disclosed is an optical fiber having a desired dispersion value to sufficiently suppress a non-linearity phenomenon, that is, a four-wave mixing phenomenon, occurring at a channel spacing of 50 GHz while minimizing the expense consumed for a compensation for dispersion. The optical fiber satisfies optical characteristics defined by a dispersion value of 7 to 10 ps/nm-km at a wavelength of 1,550 nm, a zero dispersion wavelength of 1,450 nm or less, and a cut-off wavelength of 1,250 nm or less. The optical fiber includes a core having a desired diameter (d1) and a desired refractive index (n1), the cladding surrounding the core and having a refractive index (ncl) less than the (n1), of the core (ncl<n1) or (n2) less than the outer cladding (n2<ncl). The (n2) of the inner cladding may also be less than the (n1) of the core and more than the (ncl) of the outer cladding.