Programmable access to microresonator solitons with modulational sideband heating

Abstract

Dissipative Kerr solitons formed in high-Q optical microresonators provide a route to miniaturized optical frequency combs that can revolutionize precision measurements, spectroscopy, sensing, and communication. In the past decade, a myriad of integrated material platforms have been extensively studied and developed to create photonic-chip-based soliton combs. However, the photo-thermal effect in integrated optical microresonators has been a major issue preventing simple and reliable soliton generation. Several sophisticated techniques to circumvent the photo-thermal effect have been developed. In addition, instead of the single-soliton state, emerging applications in microwave photonics and frequency metrology prefer multi-soliton states. Here, we demonstrate an approach to manage the photo-thermal effect and facilitate soliton generation. The approach is based on a single phase-modulated pump, where the generated blue-detuned sideband synergizes with the carrier and thermally stabilizes the microresonator. We apply this technique and demonstrate deterministic soliton generation of 19.97 GHz repetition rate in an integrated silicon nitride microresonator. Furthermore, we develop a program to automatically address to the target N-soliton state, in addition to the single-soliton state, with a near 100% success rate and as short as 10 s time consumption. Our method is valuable for soliton generation in essentially any platform, even with strong photo-thermal effects, and can promote wider applications of soliton frequency comb systems for microwave photonics, telecommunications, and frequency metrology.