Time- and spectral-domain evolution of subpicosecond pulses in semiconductor optical amplifiers

The evolution of ultrashort pulses in semiconductor laser amplifiers is modeled, including the effects of gain dispersion, slow and fast carrier dynamics, and self-phase modulation, which includes an instantaneous response (n(2)). The temporal and spectral evolution of 2-ps and 500-fs pulses differ considerably. This is due mainly to saturation caused by the fast (heating) dynamics and to the phase modulation by n(2).