Self-injection locking (SIL) of semiconductor lasers to on-chip microcavities enables significant laser noise purification and diverse nonlinear optical actions. Realizing nonlinear SIL in new material platforms is essential for advancing photonic integrated circuits. Here, we demonstrate nonlinear SIL in AlN microcavities that generates stimulated Raman lasers (SRLs) and microcombs. We achieve SRL emission with an output power exceeding 10 mW and a fundamental linewidth below 70 Hz in the 1750 nm band. The Kerr effect further mediates stimulated emissions at the second-Stokes and anti-Stokes frequencies. Multi-timescale thermal relaxations during turnkey SIL enable GHz-level frequency sweeps of the SRL and pump. Raman actions also render a Stokes platicon microcomb state with coemission in the pump and Stokes bands. Hybrid-integrated crystalline microresonators can be a versatile platform to investigate nonlinear photon-phonon interactions. locked icon locked icon locked icon locked icon locked icon locked icon locked icon locked icon Physics Subject Headings (PhySH)Integrated opticsLaser dynamicsFrequency combs & self-phase locking
Ding et al. (2025) studied this question.