An innovative design strategy for active metasurfaces, relying on the position of topological singularities to address full phase modulation of light with almost unity efficiency is presented. The metasurfaces consist of asymmetric Gires–Tournois resonators and their optical properties are computed with JCMsuite.
M. Elsawy, et al. Universal Active Metasurfaces for Ultimate Wavefront Molding by Manipulating the Reflection Singularities. Laser & Photonics Reviews, 17, 2200880 (2023).