Churaev, MikhailWang, Rui NingRiedhauser, AnninaSnigirev, ViacheslavBlesin, TerenceMohl, CharlesAnderson, MilesH.Siddharth, AnatPopoff, YouriDrechsler, UteCaimi, DanieleHonl, SimonRiemensberger, JohannLiu, JunqiuSeidler, PaulKippenberg, Tobias J.2023-10-232023-10-232023-10-232023-06-1310.1038/s41467-023-39047-7https://infoscience.epfl.ch/handle/20.500.14299/201763WOS:001061547600033The availability of thin-film lithiumniobate on insulator (LNOI) and advances in processing have led to the emergence of fully integrated LiNbO3 electro-optic devices. Yet to date, LiNbO3 photonic integrated circuits have mostly been fabricated using non-standard etching techniques and partially etched waveguides, that lack the reproducibility achieved in silicon photonics. Widespread application of thin-film LiNbO3 requires a reliable solution with precise lithographic control. Here we demonstrate a heterogeneously integrated LiNbO3 photonic platform employing wafer-scale bonding of thin-film LiNbO3 to silicon nitride (Si3N4) photonic integrated circuits. The platform maintains the low propagation loss (<0.1 dB/cm) and efficient fiber-to-chip coupling (<2.5 dB per facet) of the Si3N4 waveguides and provides a link between passive Si3N4 circuits and electro-optic components with adiabatic mode converters experiencing insertion losses below 0.1 dB. Using this approach we demonstrate several key applications, thus providing a scalable, foundry-ready solution to complex LiNbO3 integrated photonic circuits.Multidisciplinary SciencesScience & Technology - Other Topicsbroad-bandmodulatorgenerationconversioncircuitstext::journal::journal article::research article