Laser mode braiding on a chip

Nature Physics (2026) Cite this article The concept of topology in modern physics characterizes properties that remain invariant under continuous perturbations. In non-Hermitian systems—those containing gain or loss—topological features emerge through braids of complex eigenvalues. As parameters encircle exceptional points, the eigenvalues trace out distinct links and knots of arbitrary complexity. However, the controllable realization and direct visualization of such processes remain experimentally challenging, limiting their potential for light manipulation and device functionality. Here we demonstrate non-Hermitian braiding of laser modes on an integrated photonic chip. By actively controlling the parametric trajectories for gain and detuning, we directly observe photonic braiding through the evolution of laser frequencies and intensities. We present a rich variety of topological structures, including Hopf links, trefoil knots and Solomon links. Our chip-based platform offers scalable and programmable control over non-Hermitian dynamics. It enables robust light manipulation and reconfigurable lasing behaviour and can serve as a versatile test bed for exploring topological photonics. These results also open a pathway towards implementing synthetic topological structures on chip-scale photonic systems.This is a preview of subscription content, access via your institution Access Nature and 54 other Nature Portfolio journals Get Nature+, our best-value online-access subscription $32.99 / 30 days cancel any timeSubscribe to this journal Receive 12 print issues and online access $259.00 per yearonly $21.58 per issueBuy this articleUSD 39.95Prices may be subject to local taxes which are calculated during checkoutThe data supporting the findings of this study are available via figshare at https://doi.org/10.6084/m9.figshare.31883344 (ref. 47). Source data are provided with this paper.Adams, C. C.

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NRF-CRP23-2019-0005, NRF-CRP23-2019-0007 and NRF-CRP29-2022-0003), the mid-size centre (Grant No. NRF-MSG-2023-0002) and a National Science Foundation Investigatorship (Grant No. NRF-NRFI08-2022-0001).These authors contributed equally: Wenbo Mao, Bofeng Zhu.Department of Electrical and Systems Engineering, Washington University, St Louis, MO, USAWenbo Mao, Qian Zhang, Weijie Xu, Di Jia, Fu Li & Lan YangDivision of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, SingaporeBofeng Zhu, Qi Jie Wang & Y. D. ChongCentre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore, SingaporeBofeng Zhu, Qi Jie Wang & Y. D. ChongDepartment of Mechanical Engineering and Materials Science, Washington University, St Louis, MO, USAYuan Meng & Sang-Hoon BaeSchool of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, SingaporeChongwu Wang & Qi Jie WangThe Institute of Materials Science and Engineering, Washington University, St Louis, MO, USASang-Hoon BaeSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarL.Y. and Y.D.C. conceived of the project. W.M. designed the experiments with help from B.Z. B.Z. conceived of the theoretical model and performed the simulations. W.M. fabricated the device with help from Q.Z. and W.X. W.M. performed the experiments and analysed the experimental data. All authors discussed the results and contributed to the writing of the article. L.Y., Y.D.C. and Q.J.W. supervised the project.Correspondence to Y. D. Chong or Lan Yang.The authors declare no competing interests.Nature Physics thanks Zhenghua An, Warren Jin and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.Supplementary Sections 1–4, Tables 1–3 and Figs. 1–13.Theoretical calculations and simulations in Fig. 1d.Measured results of tuning complex laser resonances in Fig. 2b–e.Measured spectra and braiding results in Fig. 3d,e.Measured braiding results in Fig. 4a–d.Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.Reprints and permissionsMao, W., Zhu, B., Zhang, Q. et al. Laser mode braiding on a chip. Nat. Phys. (2026). https://doi.org/10.1038/s41567-026-03288-2Download citationReceived: 22 September 2025Accepted: 09 April 2026Published: 12 May 2026Version of record: 12 May 2026DOI: https://doi.org/10.1038/s41567-026-03288-2Anyone you share the following link with will be able to read this content:Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative