Generation of high frequency trains of chirped soliton-like pulses in inhomogeneous and cascaded active fiber configurations

We present a theoretical formalism of description of soliton-like pulse generation in longitudinally inhomogeneous active optical fibers. Dynamics of the wave packet during the nonlinear stage of the modulation instability is described for fibers with distributed gain and group velocity dispersion profiles. Generation of pico- and sub-picosecond pulse trains operating in THz repetition range from quasi-continuous pump wave is simulated for fibers of different inhomogeneity and for cascade fiber configurations comprising homogeneous and inhomogeneous segments. Pulse train generation is shown to occur in resonant manner once the gain and GDV distributed fiber profiles are perfectly matched.