Nonlinear wave mixing in optical microresonators new perospects for compact optical frequency combs with many promising applications. We demonstrate simultaneous generation of multiple frequency combs from a single optical microresonator and a single continuous-wave laser. Similar to space-division multiplexing, we generate several dissipative Kerr soliton states – circulating solitonic pulses driven by a continuous-wave laser – in different spatial (or polarization) modes of a MgF<sub>2</sub> microresonator. Up to three distinct combs are produced simultaneously, featuring excellent mutual coherence and substantial repetition rate differences, useful for fast acquisition and efficient rejection of soliton intermodulation products. This method could enable the deployment of dual- and triple-comb-based methods to applications where they remained impractical with current technology.
We introduce a technique capable to produce and control stabilized single-frequency emission with a sub-kHz linewidth and independently soliton comb generation from a multi–frequency regular Fabry-Perot laser diode selfinjection locked to a high-Q optical microresonator. We also observed novel regimes of controllable single, dual, and multiple-frequency generation that may be useful for the creation of narrow-linewidth lasers required for the spectroscopy, LIDARs, and telecommunications. For analysis of the considered effects original theoretical models taking into account self-injection locking effect, mode competition and Bogatov asymmetric mode interaction were developed and numerical modeling was performed.
Kerr frequency combs in optical passive microresonators promise new breakthroughs in photonics. Such combs result from multiple hyper-parametric four-wave mixing processes when reaching a threshold of modulational instability. These combs however have chaotic nature. It was revealed in recent experiments, theoretical and numerical analysis that transition form these chaotic states to highly ordered states associated with dissipative Kerr solitons is possible. In this report we discuss theoretical approaches to analyze these soliton states and reveal methods of reliable transition to single soliton states. Latest experimental results with soliton combs are reported.