Electrically Tunable Bifocal Metalens with Diffraction-Limited Focusing and Imaging at Visible Wavelengths (Adv. Sci. 21/2021)

Electrically Tunable Bifocal Metalens In article number 2102646, Junsuk Rho and co‐workers present an electrically tunable bifocal metalens operating at visible wavelengths by combining a metalens that exploits both propagation and geometric phase with a liquid crystal cell to control the state of the incident circularly polarized light. Diffractionlimited focusing and real‐time imaging of stacked positive targets are experimentally demonstrated.