Dual Optical Feedback Dynamics of Quantum Dot Lasers in Silicon-Based Photonic Integrated Circuits

This work investigated the dynamic characteristics of quantum dot lasers under dual optical feedback by solving the rate equations in time-domain. Within long cavity feedback, the route to chaos of the quantum dot lasers and its dependence on the short cavity feedback dynamics are studied. The combination of the reduction of short cavity length and the increase of short cavity feedback strength can reinforce the coupling efficiency between the laser and the waveguide, thereby enhancing the insensitivity of the laser to external long cavity feedback. These results offer valuable insights for optimizing feedback insensitivity of quantum dot lasers for isolator-free photonic integrated circuits on silicon.