Dynamics and Phase Noise of Time-Delayed Laser Diode with Non-Radiative Recombination Rate

In our study, we investigated how the strength of optical feedback and the non-radiative recombination rate impact a laser diode's dynamics and phase noise. To analyze laser dynamics, we solved numerically improved time-delay rate equations across a wide range of optical feedback strength and non-radiative recombination rates. The laser's dynamics will be categorized based on the bifurcation diagrams of the photon number. Our findings show that the non-radiative recombination rate has a significant effect on the intensity, states, and dynamic behavior of the laser diode's phase noise. A decrease in the non-radiative recombination rate results in the laser transitioning faster from a continuous wave to periodic oscillation under strong optical feedback. In the chaotic region, the non-radiative recombination rate causes a slight shift in the phase fluctuations compared to the laser operating without optical feedback. Lower non-radiative recombination rates stabilize the laser output and enable continuous wave or periodic oscillation at higher current levels. In the strong optical feedback region, a reduction in the non-radiative recombination rates shifts the chaotic operation to stable modes such as a continuous wave or periodic oscillation, and the phase noise approaches the quantum noise level. Our study emphasizes the key roles of the non-radiative rate and optical feedback in manipulating the dynamics and phase noise of a laser diode. We have shown that losses due to non-radiative rates could be practically useful for engineering laser behaviors. The strength of optical feedback can be adjusted to achieve the optimal goals of stabilizing laser operation. Our work is driven by the ongoing interest in finding effective ways to control and optimize the output of a laser diode. We believe that our findings may have potential applications in future experimental design and optimization, which will be of general interest to the community studying solid-state semiconductor laser diodes.