Abstract: A new dispersion managed soliton transmission system where the D map period is the same as the amplifier period and the pulse breathing the in the +D sections of the D maps is approximately symmetrical. Pulse breathing symmetry by one or both of two techniques. In one technique a guiding filter is placed at the beginning of the D map period such that the guiding filter reduces the bandwidth of soliton pulses passing through it by a minimum amount. Consequently, pulse breathing symmetry is restored. The path average pulse energy vs. D behavior of solitons propagating through the D map is changed such that (1) solitons of modest bandwidths have adequate energy at or near D=to provide for error-free transmission over transoceanic distances at or near D=0, and (2) such that the path average pulse energy is nearly independent of D, at or near D=0 for solitons of various pulse widths. The transmission system having this D map is much more tolerant of variations in D and pulse width than the prior art.

Abstract: A method and apparatus for producing a flat gain over very broad gain bands utilizing backward-pumped Raman amplification. The method allows for dynamic gain control through simple electronic means.

Abstract: In soliton transmission, third order dispersion of the transmission fibers tends to cause unacceptable variation in the filter strength parameter, .eta. over the wide wavelength bands required for massive wavelength division multiplexing (WDM). The effect of dispersion is substantially eliminated by varying the mirror reflectivities R(.lambda.) of etalon filters with wavelength, such that the strength (.eta.) parameter, in soliton units, essentially remains at the optimal value across the entire WDM transmission band.

Abstract: The specification relates to a method and apparatus for all-optical regeneration of return-to-zero (RZ) data streams. The effect of self-phase modulation (SPM) of a data signal passing through a nonlinear medium (NLM) creates spectral broadening in individual data pulses which are then subsequently filtered to pass a selected bandwidth centered at a frequency, .omega..sub.f, which is shifted with respect to the input data carrier frequency, .omega..sub.0. Since the degree of broadening of a pulse passing through the NLM is a function of the initial intensity of the pulse, noise in data "zeros" (null values) possess insufficient intensity (providing incidental distortion pulse intensity attributable to accumulated process noise is less than a critical value) to cause the requisite amount of spectral broadening to encompass the selected filter bandwidth centered around .omega..sub.f, and the noise is subsequently suppressed.

Abstract: A dispersion-tapered fiber for use in a soliton transmission system having lumped amplifiers to substantially reduce loss associated with pseudo phase matching and to relax the limitations on minimum allowable channel spacing caused by cross-phase modulation. The dispersion tapered fiber has a dispersion tapered either continuously or in steps, in conformity with the fiber loss curve.