Physics

Microstrip

Bound state

Mathematics

Crystallography

Optics

Statistics

Circular dichroism

Chirality (physics)

Dielectric

Dissipation

Physical chemistry

Circular polarization

Nambu–Jona-Lasinio model

Chemistry

Polarization (electrochemistry)

Chiral symmetry

Quantum mechanics

Realization (probability)

Quark

Physical Review Letters

We demonstrate that rotationally symmetric chiral metasurfaces can support sharp resonances with the maximum optical chirality determined by precise shaping of bound states in the continuum (BICs). Being uncoupled from one circular polarization of light and resonantly coupled to its counterpart, a metasurface hosting the chiral BIC resonance exhibits a narrow peak in the circular dichroism spectrum with the quality factor limited by weak dissipation losses. We propose a realization of such chiral BIC metasurfaces based on pairs of dielectric bars and validate the concept of maximum chirality by numerical simulations.

Metasurfaces with Maximum Chirality Empowered by Bound States in the Continuum