Real-time transition dynamics and stability of laser frequency microcombs

Femtosecond mode-locked laser frequency combs have served as the cornerstone in precision spectroscopy, all-optical atomic clocks, and measurements of ultrafast dynamics. Recently frequency microcombs based on nonlinear microresonators have been examined – affording remarkable precision approaching that of laser frequency combs, and now on a solid-state chip-scale platform and from a fundamentally different physical origin. Here we unravel the transitional dynamics of frequency microcombs from chaotic background routes to femtosecond mode-locking in real-time, enabled by our ultrafast temporal magnifier metrology and enlarged stability of dispersion-managed dissipative solitons. Through our dispersion-managed oscillator, we report a stability zone more than an order-of-magnitude larger than prior static homogeneous counterparts, providing a novel platform for understanding ultrafast dissipative dynamics and offering a new path towards high-power frequency microcombs.