2020/06/09 by Adam Overvig, Nanfang Yu, Andrea Alù +1 · 414 citations
Engineering · Materials Science · Physics and Astronomy · #Bound state #Classical mechanics #Fano plane #Fano resonance #Geometric phase #Geometry #Metamaterial #Metamaterials and Metasurfaces Applications #Nanophotonics #Optics #Orbital Angular Momentum in Optics #Physics #Plasmon #Plasmonic and Surface Plasmon Research #Polarization (electrochemistry) #Quantum #Quantum mechanics #Quantum optics #physics.optics
paper · pdf · doi:10.1103/physrevlett.126.073001
published in Physical Review Letters 126(7), 073001 (American Physical Society) · 33 pages, 6 figures
arxiv created 2020/06/09 · openalex publication_date 2021/02/17 · arxiv updated 2021/02/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Quasi-bound states in the continuum (QBICs) are Fano resonant states with long optical lifetimes controlled by symmetry-breaking perturbations. While conventional Fano responses are limited to linear polarizations and do not support tailored phase control, here we introduce QBICs born of chiral perturbations that encode arbitrary elliptical polarization states and enable geometric phase engineering. We thereby design metasurfaces with ultrasharp spectral features that shape the impinging wave front with near-unity efficiency. Our findings extend Fano resonances beyond their conventional limits, opening opportunities for nanophotonics, classical and quantum optics, and acoustics.