Dynamic metasurface design and functional devices

A dynamic metasurface is a metasurface in which adjustable elements are integrated into static metaatoms and whose functions are controlled by different external excitation methods. Various adjustable devices have been realized based on dynamic metasurfaces,including frequency conversion filters or absorbers,zoom lenses,dynamic beam controllers,dynamic holographic elements,etc. In this review,first,the modulation method of dynamic metasurfaces is summarized systematically,and then the related research work is reviewed. Dynamic metasurfaces can be divided into two categories:one is a uniformly regulated dynamic metasurface that controls all metaatoms uniformly,and is used to achieve dynamic conversion of spectrum,polarization,and wavefront;the other is a dynamically reconfigurable/programmable metasurface with individually controlled metaatoms,and is used to realize flexible control of the wavefront. Dynamic devices with flexible and controllable functions are the main direction of future research on metasurfaces. The existing dynamic devices are summarized,and the development direction and challenges of dynamic metasurfaces are further discussed and prospected.