Dynamic electrical control of on-chip second-harmonic generation with ferroelectric NbOBr2
Abstract Niobium oxide dihalides such as NbOCl2, featured by vanishing interlayer electronic coupling, present thickness-scalable strong second-harmonic generation (SHG), which has demonstrated their compelling performance of free-space nonlinear optics (NLO). However, practical on-chip photonic applications demand not only high NLO efficiency but also robust electrical tunability, a critical capability that has remained elusive until now. Our work reports the first realization of an in-situ electrically tunable NLO response within a NbOBr2-photonic integrated circuit (PIC). This material uniquely combines two critical features: exceptional tunability enabled by in-plane ferroelectricity and a strong second-order susceptibility resulting from its intrinsic broken-inversion symmetry. In this on-chip photonic circuitry scenario, NbOBr2 showcases larger SHG efficiency than NbOCl2 because of its low index contrast and completely outperforms NbOCl2 in the modulation capability thanks to much stronger in-plane ferroelectricity of NbOBr2. We achieve dynamic, non-volatile SHG intensity modulation exceeding 53%, with polarization states retained even after removing the external electric field. This work establishes the integration of 2D ferroelectric NbOBr2 into PICs as a transformative approach for developing scalable and reconfigurable ultracompact NLO devices, opening new avenues for versatile applications in tunable light sources, optical information processing, and quantum photonics.
Authors
- Wonkeun Chang (ORCID: https://orcid.org/0000-0002-0735-0447)
- Lalit Singh (ORCID: https://orcid.org/0000-0002-3212-8485)
- Xiaoxu Zhao (ORCID: https://orcid.org/0000-0001-9746-3770)
- Yuhui Yang (ORCID: https://orcid.org/0000-0001-6682-6006)
- Qingyun Wu (ORCID: https://orcid.org/0000-0003-2040-9615)
- Wenduo Chen (ORCID: https://orcid.org/0009-0005-3156-1710)
- Qijie Wang (ORCID: https://orcid.org/0000-0002-9910-1455)
- Nanxi Li (ORCID: https://orcid.org/0000-0002-0524-0949)
- Jinpeng Huo (ORCID: https://orcid.org/0000-0001-7858-0648)
- Sang Hoon Chae (ORCID: https://orcid.org/0000-0002-9612-5371)
- Beng Kang Tay (ORCID: https://orcid.org/0000-0002-3776-3648)
- Yue Gong (ORCID: https://orcid.org/0000-0002-5764-3117)
- L. K. Ang (ORCID: https://orcid.org/0000-0003-2811-1194)
- Jia Xu Brian Sia (ORCID: https://orcid.org/0000-0003-4494-8293)
- Cheng‐Wei Qiu (ORCID: https://orcid.org/0000-0002-6605-500X)
- Zheng Liu (ORCID: https://orcid.org/0000-0002-8825-7198)
- Xin Guo
- Sung-Gyu Lee (ORCID: https://orcid.org/0000-0003-3757-5863)
Institutions
- Agency for Science, Technology and Research (SG)
- Singapore University of Technology and Design (SG)
- National University of Singapore (SG)
- Nanyang Technological University (SG)
- Peking University (CN)
- Southern University of Science and Technology (CN)
- Institute of Microelectronics (SG)
- CNRS-International-NTU-Thales Research Alliance (SG)
- Sungkyunkwan University (KR)
Publication Details
- Journal
- Nature Nanotechnology
- Published
- 2026-11-09
- DOI
- https://doi.org/10.1038/s41565-026-02331-w
- Citations
- 4
- Primary Topic
- Photorefractive and Nonlinear Optics
- Type
- article
- Field-Weighted Citation Impact
- 2.43
Funders
- National Research Foundation
- Ministry of Education - Singapore
- National Natural Science Foundation of China
- Ministry of Education, India
- Bộ Giáo dục và Ðào tạo