Xu, LeiZangeneh Kamali, KhosroHuang, LujunRahmani, MohsenSmirnov, AlexanderCamacho-Morales, RocioMa, YixuanZhang, GuoquanWolley, MattNeshev, DragomirMiroshnichenko, Andrey E.2025-06-292025-06-29ORCID:/0000-0002-6102-7157/work/169578914ORCID:/0000-0002-4508-8646/work/169579788http://www.scopus.com/inward/record.url?scp=85172468800&partnerID=8YFLogxKhttps://hdl.handle.net/1885/733765320We propose an ultra-thin silicon metasurface supporting a high-quality quasi-bound-state-in-the-continuum (BIC) generated by the collective magnetic dipole (MD) resonance excited in the subdiffractive periodic systems. Such quasi-BIC MD state leads to a robust near-field enhancement and a significant boost of the nonlinear process, resulting in measured 500-fold enhancement of third-harmonic emission in comparison to the conventional silicon disk metasurface. We further demonstrate the highly-efficient dynamical switching experimentally over nonlinear images via polarisation and wavelength control, opening the way for various applications in highly-efficient nonlinear metadevices including tunable laser, tunable displays, nonlinear imaging.The authors acknowledge the funding support provided by the Australian Research Council (ARC) and UNSW Scientia Fellowship program. The authors also appreciate the use of Australian National Fabrication Facility (ANFF)the ACT Node.2enPublisher Copyright: © 2019, META Conference. All rights reserved.201985172468800