Self-regulating soliton switching waves in microresonators

Abstract

Dissipative soliton Kerr frequency combs in microresonators have recently been demonstrated with the self-injection locking process. In addition to turnkey deterministic comb generation, this mode of operation simplifies dark pulse generation in the normal dispersion regime. Here, the formation process of dark pulses triggered by self-injection locking is studied by regarding them as a pair of switching waves that connect domains having different intracavity powers. The self-injection locking mechanism allows the switching waves to self-regulate their position so that a wide range of comb states can be accessed, and the duty cycle is controlled by the feedback phase. The dark pulse shape is also imaged using the linear optical sampling technique. The results provide physical insights as well as an operational modality for this important class of nonlinear waves.