Experimental Injection Map of Semiconductor Laser Submitted to Filtered Feedback

Optical injection consists in the unidirectional coupling between a “slave” laser (SL) and a “Master” laser (ML). The injected SL may exhibit different behaviors, showing frequency locking, wave mixing, relaxation regimes, period doubling, and chaos. The different regimes may be mapped on a chart where the injected power and the detuning between the slave and the master frequencies are varied. In this paper, a detailed overview of the regimes are given when the SL is submitted to both optical injection and filtered optical feedback. This last coupling is realized thanks to an extended cavity, which includes a frequency filter. When the SL is operating far from threshold (4 I_th), typical regimes mentioned for feedback-free laser are observed for all the external-cavity modes. On the contrary, when the SL operates close to threshold (1.5 I_th), it is shown that the dynamics is wealthier. New regimes, as one for which simultaneously chaos and locking occur, can be identified, in comparison to the case of a single-frequency SL.