Recent Advances in Polarization‐Encoded Optical Metasurfaces

In recent years, optical metasurfaces, i.e., surface‐confined arrays of engineered nanostructured elements (meta‐atoms), have become an emerging research area due to their unprecedented capabilities of manipulating light with subwavelength spatial resolutions. The metasurfaces revolutionize thereby conventional bulky optics with compact planar elements. As the polarization is one of the intrinsic properties of light and of crucial importance for fundamental sciences and practical applications, the polarization‐encoded functional optical metasurfaces featuring compactness, integration compatibility, and multiple functionalities have been in the focus of intensive research and development. Herein, the basic principles and emerging applications of polarization‐encoded functional metasurfaces operating in the optical range are reviewed. Starting with the description of different polarization states, the review proceeds with considerations of how to interconvert and detect the state of polarization. The main achievements in polarization‐multiplexing metasurface components (metadevices) are then summarized. Finally, a personal outlook on potential directions in this fast‐growing research area is provided in the conclusions.