International audienceUsing the conventional rate equations describing an injection-locked system, a novel modulation response function is derived, which implicitly incorporates nonlinear gain through the free-running relaxation oscillation frequency and damping rate of the slave laser. In this paper, it is shown that the model presented can be used to extract the characteristic parameters of the coupled system from experimental data. The number of fitting parameters in the model is reduced by determining the fundamental slave parameters through the conventional free-running response function; these parameters are considered to be constant during the curve-fitting of the injection-locked system. Furthermore, in order to reduce the number of possible solutions generated during the least-squares-fitting process, the remaining fitting parameters are tightly constrained based on the physical limits of the coupled system. By reducing the number of unknown fitting parameters and constraining the remaining terms, a stronger confidence in the extracted parameters is achieved. Using a series of response curves measured from an injection-locked quantum dash laser, characteristic parameters of the system are extracted and validity of the model is examined. The verified model is used to analyze the impact of the linewidth enhancement factor on the characteristics of the response function in the microwave domain

International audienceDynamic feedback properties of a 1.55 μm InAs/InP quantum dash laser are reported. The ground state linewidth enhancement factor (αH-factor) is found to be enhanced from ∼ 1 to ∼ 14 as the bias current is increased beyond the threshold value. As a consequence of the variation in the αH-factor, the feedback sensitivity of the quantum dash semiconductor laser is dramatically affected over the entire range of operational currents. The onset of its critical feedback regime, which is incompatible with data transmission, is shown to exhibit a variation of approximately 20 dB for the quantum dash device

This work investigates the behavior of a zero-detuned optically-injected quantum-dash Fabry-Perot laser as the injected field ratio is increased from near-zero to levels resulting in stable locking. Using a normalized model describing optically-injected semiconductor lasers, variations in the slave laser's free-running characteristics are shown to have a strong impact on the coupled system's behavior. The theoretical model is verified experimentally using a high resolution spectrometer. It is found that the quantum-dash laser has the technological advantage of a low linewidth enhancement factor at low bias currents that suppresses undesirable Period-2 and chaotic behavior. Such observations suggest that optically-injected quantum-dash lasers can be used as an enabling component for tunable photonic oscillators.

No abstract

No abstract