Aigner, AndreasAndreasAignerLigmajer, FilipFilipLigmajerRovenská, KatarínaKatarínaRovenskáHolobrádek, JakubJakubHolobrádekIdesová, BeátaBeátaIdesováMaier, Stefan A.Stefan A.MaierTittl, AndreasAndreasTittlMenezes, Leonardo de S.Leonardo de S.Menezes2026-03-192026-03-192024-08-27Nano Letters 24 (35): 10742-10749 (2024)https://hdl.handle.net/11420/62085Active functionalities of metasurfaces are of growing interest in nanophotonics. The main strategy employed to date is spectral resonance tuning affecting predominantly the far-field response. However, this barely influences other essential resonance properties like near-field enhancement, signal modulation, quality factor, and absorbance, which are all vital for numerous applications. Here we introduce an active metasurface approach that combines temperature-tunable losses in vanadium dioxide with far-field coupling tunable symmetry-protected bound states in the continuum. This method enables exceptional precision in independently controlling both radiative and nonradiative losses. Consequently, it allows for the adjustment of both the far-field response and, notably, the near-field characteristics like local field enhancement and absorbance. We experimentally demonstrate continuous tuning from under- through critical- to overcoupling, achieving quality factors of 200 and a relative switching contrast of 78%. Our research marks a significant step toward highly tunable metasurfaces, controlling both near- and far-field properties.en1530-69922024351074210749ACS Publ.Active metasurfacesbound states in the continuumloss tunabilitynear-field tunabilityvanadium dioxideTechnology::600: TechnologyJournal Article10.1021/acs.nanolett.4c01703Journal Article