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

• DOI: 10.48550/arxiv.2112.02018
• Publication Date: 2021-01-01
• Authors: Mikhail Churaev; Rui Ning Wang; Viacheslav Snigirev; Annina Riedhauser; Terence Blésin; Charles Möhl; Miles A. Anderson; Anat Siddharth; Youri Popoff; Daniele Caimi; Simon Hönl; Johann Riemensberger; Junqiu Liu; Paul Seidler; Tobias J. Kippenberg
• Keywords: 0301 basic medicine; 0303 health sciences; 03 medical and health sciences; Science; Q; FOS: Physical sciences; Physics - Applied Physics; Applied Physics (physics.app-ph); Article; Physics - Optics; Optics (physics.optics)

The availability of thin-film lithium niobate on insulator (LNOI) and advances in processing have led to the emergence fully integrated LiNbO3 electro-optic devices, including low-voltage, high-speed modulators, frequency combs, microwave-optical transducers. Yet date, photonic circuits (PICs) mostly been fabricated using non-standard etching techniques that lack reproducibility routinely achieved silicon photonics. Widespread future application requires a reliable scalable solution standard precise lithographic control. Here we demonstrate heterogeneously platform overcomes abovementioned challenges by employing wafer-scale bonding planarized low-loss nitride (Si3N4) circuits, mature foundry-grade platform. resulting devices combine substantial Pockels effect with scalability, high-yield, complexity underlying Si3N4 PICs. Importantly, maintains low propagation loss (<0.1 dB/cm) efficient fiber-to-chip coupling (<2.5 dB per facet) waveguides. We find ten transitions between mode confined PIC hybrid LiNbO$_3$ produce less than 0.8 additional loss, corresponding transition not exceeding 0.1 dB. These nearly lossless adiabatic thus link passive structures components. high-Q microresonators, optical splitters, electrically tunable dimers, carrier-envelope phase detection femtosecond laser same platform, providing foundry-ready complex circuits.