Lithium-niobate-based narrow-linewidth frequency agile integrated lasers with petahertz frequency tuning rate

We demonstrate an electro-optically tunable hybrid integrated laser self-injection locked to a mode of a heterogeneously integrated lithium-niobate-on-Damascene-silicon-nitride microresonator. An intrinsic linewidth of 3 kHz and a frequency tuning rate of 12 × 1015 Hz/s were observed. Proof-of-principle coherent LiDAR experiments were performed.