High-gain waveguide amplifiers in SigN4 technology via double-layer monolithic integration

Silicon nitride(SiN)-on-SiO,attracts increasing interest in integrated photonics owing to its low propagation loss and wide transparency window,extending from^400 nm to 2350 nm.Scalable integration of active devices such as amplifiers and lasers on the Si;N,platform will enable applications requiring optical gain and a much-nceded alternative to hybrid integration,which suffers from high cost and lack of high-volume manufacturability.We demonstrate a high-gain optical amplifier in Al2O3:Er^3+ monolithically integrated on the Si3N4 platform using a double photonic layer approach.The device exhibits a net Si3N4-to-Si3N4 gain of 18.11±0.9 dB at 1532 nm,and a broadband gain operation over 70 nm covering wavelengths in the S-,C-and L-bands.This work shows that rare-carth-ion-doped materials and in particular,rare-earth-ion-doped Al.05,can provide very high net amplification for the Si3N4 platform,paving the way to the development of different active devices monolithically integrated in this passive platform.