Gorkunov, MaximAntonov, AlexanderMuljarov, EgorKivshar, Yuri2025-05-232025-05-239798350373493ORCID:/0000-0002-3410-812X/work/184104872http://www.scopus.com/inward/record.url?scp=85207819329&partnerID=8YFLogxKhttps://hdl.handle.net/1885/733752640Dielectric metasurfaces with eigenstates designed to selectively couple to circularly polarized light offer a game-changing platform for advanced chiral metaphotonics. Current designs rely on breaking the mirror symmetry by variable height, elevation or tilt of subwavelength meta-atoms, which complicates their fabrication. We discuss novel strategies for achieving maximum optical chirality with metasurfaces composed of flat layers processed with conventional two-dimensional lithography. Apart from extrinsic-chiral arrangements, which owe their broken mirror symmetry to a sample tilt, various single- and multi-layer designs are capable of maximizing intrinsic chirality at the normal incidence. We reveal specific conditions, when even weak symmetry-breaking effect of a transparent substrate can lead to maximum chirality.M.G. and A.A. gratefully acknowledge the support from the Russian Science Foundation (project 23-42-00091). Y.K. was supported by the Australian Research Council (Grant DP210101292) and the International Technology Center Indo-Pacific (ITC IPAC) via Army Research Office (contract FA520923C0023).enPublisher Copyright: © 2024 IEEE.202410.1109/Metamaterials62190.2024.1070331185207819329