A heterogeneously integrated lithium niobate-on-silicon nitride photonic platform

We present a LiNbO
3
integrated photonic platform with wafer-scale bonding to a Si
3
N
4
photonic circuit. The platform exhibits <0.1 dB/cm propagation loss and <2.5 dB/facet fiber-chip coupling loss. We demonstrate phase shifters, frequency-agile lasers, optical splitters, and other devices.