Thermally stable access to microresonator solitons via slow pump modulation.

Temporal dissipative Kerr solitons (DKSs) in microresonators provide ultra-short optical pulses and low-noise frequency combs with gigahertz to terahertz repetition rates. Owing to their unique properties, they have found application in fields, including optical communications, rapid laser ranging, and optical precision spectroscopy. However, due to the thermal instability encountered when entering the DKS regime, the stable generation of solitons remains challenging for many systems and usually requires rapid actuation of the pump laser detuning, pulsed driving, additional lasers, a particular mode structure and/or active feedback loops to stabilize the system. Here we show that slow pump modulation can remove the thermal instability and enable passively stable soliton states that can be readily accessed via arbitrarily slow laser tuning, thereby greatly reducing the technical complexity of stable DKS generation.