Low-loss heterogeneously integrated barium-titanate-on-silicon-nitride photonics

We present a hybrid barium titanate photonics platform exhibiting exceptionally low losses of 0.7 dB/cm and realize ring resonators with intrinsic quality factors exceeding 6×10
⁵
. Measurement of V
π
L = 0.56 V•cm in electro-optic modulation experiments demonstrates the platform’s potential.