We fabricated various optical devices on a hybrid Si3N4-LiNbO3 platform for integrated quantum photonic circuits and observed Hong-Ou-Mandel (HOM) quantum interference. Strip-loaded waveguides were prepared via Si3N4 deposition on LiNbO3. Consequently, fundamental building blocks for quantum photonics, such as ring resonators, various beam splitters, and Mach-Zehnder interferometers, were fabricated and tested. Using 50:50 beam splitters, we observed HOM quantum interference and achieved a visibility of 96.6 ± 1.2% after the subtraction of accidental counts. More advanced quantum-integrated devices are expected to be realized using the proposed hybrid platform.
This work was supported in part by the National Research Foundation of Korea (NRF) under Grant 2022M3K4A1097119 and Grant 2023M3K5A1094805; in part by the Institute for Information and Communications Technology Promotion (IITP) under Grant 2020-0-00947, Grant 2020-0-00890, and Grant RS-2023-00222863; in part by the National Research Council of Science and Technology (NST) under Grant CAP21034-000; and in part by the Korea Institute of Science and Technology (KIST) Research Program under Grant 2E32941 and Grant 2E32971.
