Abstract: An optical transmission system designed for gigabit pulse rates and Raman pumping in which there is essentially no pre-dispersion compensation and the in-line dispersion compensation at the start of each span is overcompensation of between 110 and 120 of the compensation needed to neutralize the dispersion of its immediately preceding span.

Abstract: A Raman-amplified optical transmission system 80 includes a source of optical transmission signals having a system wavelength, &lgr;s, that are connected to one end of the of a first optical fiber 50-1 having a large effective area, i.e., Aeff≧70 &mgr;m2. The other end of the first optical fiber is connected to a second optical fiber 50-2 having a small effective area, i.e., Aeff≦60 &mgr;m2. Preferably, the first and second optical fibers have opposite dispersion signs. A wavelength-division multiplexer 87, for example, couples optical transmission signals &lgr;1 . . . &lgr;n, from an optical pump 88 to the second optical fiber that cause it to exhibit stimulated Raman scattering, which provides amplification of the optical transmission signals. Preferably, the optical pump signals propagate along the second optical fiber in a direction that is opposite the direction of the optical transmission signals. Exemplary cables 500, 600 are disclosed that include both large and small-effective-area fibers.

Abstract: Simultaneous dense WDM operation in both the 1310 nm and 1550 nm transparency windows of silica-based optical fiber, is enabled by a fiber design providing for nulled dispersion within a critically positioned wavelength range. Design provides for values of dispersion in both windows sufficiently low for desired per-channel bit rate, and, at the same time, sufficiently high to maintain effects of non-linear dispersion within tolerable limits for WDM operation. Fiber fabrication and system design are described.

Abstract: A dispersion-balanced optical cable 90 reduces four-photon mixing in Wave Division Multiplexing (WDM) systems and is effective to reduce cumulative dispersion D substantially to zero. The dispersion-balanced optical cable 90 includes one or more optical fibers 90-1 having positive dispersion D.sub.1, and one or more optical fibers 90-2 having negative dispersion D.sub.2. The fibers are singlemode and are suitable for the transmission of optical signals in the 1550 nm region. At this wavelength, the positive-dispersion fibers have a chromatic dispersion of about +2.3 ps/nm.km, and the negative-dispersion fibers have a chromatic dispersion of about -1.6 ps/nm.km. The dispersion-balance optical cable preferably includes an equal number of positive- and negative-dispersion fibers in the same cable.