This paper demonstrates the exceptional optical feedback resilience of an InAs/GaAs quantum dot Fabry–Pérot laser, enabled by an unusually large excited state to ground-state threshold current ratio. This wide separation effectively suppresses gain competition and nonlinear coupling, allowing the device to maintain spectral purity and dynamic stability under optical feedback levels up to 16.6%, even when biased at 50 times the ground-state threshold current at room temperature. These findings further highlight the intrinsic robustness of quantum dot lasers, still positioning them as promising candidates for isolator-free operation in silicon photonics and co-packaged optics platforms, as well as for low-noise and feedback-resilient photonic systems.
Shi et al. (Mon,) studied this question.