Temporal localized states and square-waves in semiconductor micro-resonators with strong time-delayed feedback

In this paper we study the dynamics of a vertically-emitting micro-cavity operated in the Gires-Tournois regime that contains a semiconductor quantum-well and that is subjected to strong time-delayed optical feedback and detuned optical injection. Using a first principle time-delay model for the optical response, we disclose sets of multistable dark and bright temporal localized states coexisting on their respective bistable homogeneous backgrounds. In the case of anti-resonant optical feedback, we disclose square-waves with a periodic of twice the round-trip in the external cavity. Finally, we perform a multiple time-scale analysis in the good cavity limit. The resulting normal form is in good agreement with the original time-delayed model.