Abstract: A pumped Raman fiber optic amplifier includes two optical fibers whose lengths are determined so that the fibers exhibit dispersions of substantially equal magnitude and opposite sign at the wavelength of an input light signal. The fiber having the positive dispersion has a cylindrical core, an outer cladding, and a refractive index profile with respect to the outer cladding. The core has a diameter of between 3 and 6 microns (&mgr;m) and a difference (&Dgr;n) between the index of the core and the cladding is between 0.015 and 0.035. The index profile includes a trench region adjacent the circumference of the core, and the trench region has a width of between 1 and 4 &mgr;m and a &Dgr;n of between −0.005 and −0.015. The two fibers are slope matched so that the net dispersion of the amplifier remains substantially zero over a broad wavelength interval.

Abstract: An optical fiber suited for dispersion compensation with simultaneous Raman amplification. The fiber has a central core and an index profile that defines successively concentric regions radially outward of the core. The core has a diameter of between 2 and 5 microns (&mgr;m) and a refractive index difference (&Dgr;n) with respect to the outer cladding of between 0.012 and 0.035. A trench region adjacent the core is between 2 and 6 &mgr;m wide and has a negative &Dgr;n of between −0.015 and −0.003. A ring region adjacent the trench region is between 1 and 5 &mgr;m wide and has a &Dgr;n of between 0.001 and 0.015, and an inner cladding surrounding the ring region has a width of between zero and 5 &mgr;m and a &Dgr;n of between −0.011 and 0.001. A dispersion slope compensating module (DSCM) including the fiber obtains a relatively high Raman gain with respect to conventional DSCMs that are pumped for Raman amplification.

Abstract: A pumped Raman fiber optic amplifier includes two optical fibers whose lengths are determined so that the fibers exhibit dispersions of substantially equal magnitude and opposite sign at the wavelength of an input light signal. The fiber having the positive dispersion has a cylindrical core, an outer cladding, and a refractive index profile with respect to the outer cladding. The core has a diameter of between 3 and 6 microns (&mgr;m) and a difference (&Dgr;n) between the index of the core and the cladding is between 0.015 and 0.035. The index profile includes a trench region adjacent the circumference of the core, and the trench region has a width of between 1 and 4 &mgr;m and a &Dgr;n of between −0.005 and −0.015. The two fibers are slope matched so that the net dispersion of the amplifier remains substantially zero over a broad wavelength interval.