Abstract
Dynamical characteristics and their applications of the semiconductor lasers subject to dual-beam perturbations, including dual-beam optical injection (DOI) and optical injection (OI) with optical feedback (OF), are investigated. Base on the shifts of the cavity resonance frequency causing by the OI and the OF, the effects of the perturbations to the lasers can be quantitatively analysed. The roles and influences from each of the perturbations in the dual-beam perturbation schemes are also discussed. For the semiconductor lasers subject to DOI, dynamical scenarios including PP, PS, SP, SS, S'S', S'L, LS', and LL are found. These scenarios are defined and differentiated by whether the dynamics and the characteristic frequencies originated from the single-beam injection scheme are being preserved (P), shifted (S), or suppressed (S') after both beams are simultaneously injected. The letter L is used if the slave laser is already injection-locked by one of the beams under the single-beam injection condition. The mappings of these scenarios and their corresponding dynamical states are plotted in the injection strengths and detuning frequencies spaces, respectively. The transition routes among different scenarios are tracked by comparing the oscillation frequencies of the lasers subject to single-beam optical injection and DOI. Moreover, frequency-locking states are observed experimentally the first time in the DOI, which occur when the frequency pushing effects from the two injected beams with opposite detunings balance each other off. For the semiconductor lasers subject to OI with OF, dynamical scenarios including PP, PS, SP, SS, and LS' are distinguished. To study the competition between the OI and the OF in the lasers, the mapping of these scenarios and their corresponding dynamical states are plotted in the parameter space of the injection and feedback strengths. The mapping shows that the laser is more sensitive to the perturbation from the OF light than the OI light when adding both to the laser simultaneously. This mapping also 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 study, 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.