Generalized Brewster effect at exceptional points via cascaded non-Hermitian metasurfaces
Phys. Rev. Applied 24, 034030 – Published 11 September, 2025
DOI: https://doi.org/10.1103/zkw4-nylb
Abstract
The Brewster effect, a reflectionless phenomenon stemming from directional dipole radiation, is a basic principle in polarization optics. Typically, its manifestation is confined to a specific incident angle and polarization. Here, we break this constraint using cascaded non-Hermitian metasurfaces on a dielectric substrate, which collectively tailor dipole radiation, thereby enabling a generalized Brewster effect for arbitrarily selected angles and polarizations. Intriguingly, we find that this generalized Brewster effect is associated with exceptional points. Moreover, it can be achieved via diverse metasurface configurations, including dielectric, metallic, lossy, and gain metasurfaces. Microwave experiments using cascaded lossy-metallic metasurfaces confirm our theory. Our findings connect Brewster physics with non-Hermitian optics and enable advanced reflectionless wave manipulation.
