Control pulse is coupled into this pulse shaper by wavelength division multiplexer. Nonlinear phaseshift of signal laser is induced by control pulse because of cross phase modulation.
Signal laser interferes in fiber coupler, then shaped signal pulse transmits from output port of this pulse shaper. Signal pulse's waveform is determined by the profile of the nonlinear phaseshift.
Self-phase modulation of fiber does not affect the pulse shape of chaotic signal, however, its product of nonlinear phaseshift can widen the chaotic signal spectrum.