Soliton Burst and Bi-Directional Switching in the Platform with Positive Thermal-Refractive Coefficient Using an Auxiliary Laser

Dissipative Kerr solitons in optical microresonators enable the generation of stable ultrashort pulses and phase-locked frequency combs, leading to their widespread applications. For traditional platforms with positive thermal-refractive coefficient, strong thermal effect increases the difficulties of soliton triggering and prohibits the deterministic control of soliton number. Here, using an auxiliary laser to tune thermal effect, soliton burst and bi-directional switching are demonstrated in high-index doped silica glass platform. First, by varying the parameters of the auxiliary laser, the thermal effect tuning of the microresonator is studied with different thermal compensation states achieved, leading to distinct soliton switching features. Especially, the solitons burst and bi-directional switch in over-compensated state. The corresponding process is recorded in real time based on a temporal magnification system, uncovering transient dynamics from continuum background noise to soliton formation. Finally, the deterministic generation of solitons is enabled with controllable soliton number spanning from 1 to 21. The present work provides insight into soliton dynamics and enables soliton generation on demand with a large range of soliton numbers inside a single device.