Brillouin amplifiers and lasers in silicon nitride photonics with a scalable foundry process

Silicon nitride (Si₃N₄) is a cornerstone platform in integrated photonics, with ultra-low optical losses, a broad transparency from visible to NIR, and CMOS compatibility. We exploit stimulated Brillouin scattering (SBS) in standard, symmetric double-stripe (SDS) Si₃N₄, showing net-gain amplification, stimulated Brillouin lasing (SBL), Kerr nonlinear four-wave mixing (FWM) and frequency combs. These results show promise for next-generation communication, quantum technology and all-integrated atomic clocks.