Abstract
We experimentally investigate the dynamical characteristics of semiconductor lasers subject to both the optical injection (OI) and the optical feedback (OF). By coupling the OI and the OF lights into the same fiber before injecting into the slave laser (SL), the ratio between the two perturbations can be accurately determined and controlled. The frequency shifts in the cavity resonance frequency of the SL (vSL) induced by the OI and the OF lights are compared quantitatively. To study the competition between the OI and the OF in the SL, the mapping of the dynamical scenarios and states are plotted in the parameter space. This mapping serves as the guideline for choosing the appropriate operation conditions in various applications employing both the OI and the OF at the same time. In this paper, the suitable feedback strengths to narrow the linewidths of photonic microwave signals generated by the OI are studied. The limitation of using OI in enhancing the bandwidths of the chaos states generated by the OF is discussed. Moreover, to suppress the unwanted dynamics due to the feedback, the optimal injection parameters of the OI are shown. © 2013 Optical Society of America.