A heterogeneously integrated lithium niobate-on-silicon nitride photonic platform.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37311746.
- Also identified by DOI 10.1038/s41467-023-39047-7 and PMC identifier 10264395.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The availability of thin-film lithium niobate on insulator (LNOI) and advances in processing have led to the emergence of fully integrated LiNbO<sub>3</sub> electro-optic devices. Yet to date, LiNbO<sub>3</sub> 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 LiNbO<sub>3</sub> requires a reliable solution with precise lithographic control. Here we demonstrate a heterogeneously integrated LiNbO<sub>3</sub> photonic platform employing wafer-scale bonding of thin-film LiNbO<sub>3</sub> to silicon nitride (Si<sub>3</sub>N<sub>4</sub>) 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 Si<sub>3</sub>N<sub>4</sub> waveguides and provides a link between passive Si<sub>3</sub>N<sub>4</sub> 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 LiNbO<sub>3</sub> integrated photonic circuits.