Heterogeneous integration of a high-speed lithium niobate modulator on silicon nitride using micro-transfer printing

Abstract

Integrated photonic systems require fast modulators to keep up with demanding operation speeds and increasing data rates. The silicon nitride integrated photonic platform is of particular interest for applications such as datacom, light detection and ranging (LIDAR), quantum photonics, and computing owing to its low losses and CMOS compatibility. Yet, this platform inherently lacks high-speed modulators. Heterogeneous integration of lithium niobate on silicon nitride waveguides can address this drawback with its strong Pockels effect. We demonstrate the first high-speed lithium niobate modulator heterogeneously integrated on silicon nitride using micro-transfer printing. The device is 2 mm long with a half-wave voltage Vπ of 14.8 V. The insertion loss and extinction ratio are 3.3 and 39 dB, respectively. Operation beyond 50 GHz has been demonstrated with the generation of open eye diagrams up to 70 Gb/s. This proof-of-principle demonstration opens up possibilities for more scalable fabrication of these trusted and performant devices.