Symmetry breaking

Quantum mechanics

Nanopillar

Materials science

Nambu–Jona-Lasinio model

Excitation

Metamaterial

Photonics

Physics

Nanotechnology

Dipole

Dielectric

Optics

Grating

Circular dichroism

Plasmon

Crystallography

Chirality (physics)

Chemistry

Nanostructure

Chiral symmetry breaking

Birefringence

Optoelectronics

Polarizer

ACS Nano

Three-dimensional chiral plasmonic metasurfaces were demonstrated to offer enormous potential for ultrathin circular polarizers and applications in chiral sensing. However, the large absorption losses in the metallic systems generally limit their applicability for high-efficiency devices. In this work, we experimentally and numerically demonstrate three-dimensional chiral dielectric metasurfaces exhibiting multipolar resonances and examine their chiro-optical properties. In particular, we demonstrate that record high circular dichroism of 0.7 and optical activity of 2.67 × 105 degree/mm can be achieved based on the excitation of electric and magnetic dipolar resonances inside the chiral structures. These large values are facilitated by a small amount of dissipative loss present in the dielectric nanoresonator material and the formation of a chiral supermode in a 4-fold symmetric metasurface unit cell. Our results highlight the mechanisms for maximizing the chiral response of photonic nanostructures and offer important opportunities for high-efficiency, ultrathin polarizing elements, which can be used in miniaturized devices, for example, integrated circuits.

Chiral Bilayer All-Dielectric Metasurfaces