Nonlinear dynamics of optically injected self-pulsating laser diodes

The behavior of a 1.55-mum InGaAsP distributed feedback (DFB) self-pulsatin g (SP) laser diode (LD) when injected with either unmodulated or modulated light from an external LD is investigated numerically, When subjected to we ak injection of unmodulated light, the SP-LD exhibits mostly chaotic behavi or with some regions of self-sustained-pulsations and multiple-peak periodi c oscillations. As the strength of optical injection increases, the SP-LD t ransits from chaos to multiple-peak periodic oscillations followed by high- frequency self-oscillations before reaching an equilibrium state (i.e., a s teady level). When injected with modulated light, the output of the SP-LD i s dominated by either quasi-periodicity or chaos depending on the modulatio n current of the injected optical signal.