Control of the local and nonlocal electromagnetic response in all-dielectric reconfigurable metasurfaces

Reconfigurable metasurfaces are potent platforms to control the propagation properties of light dynamically. Among different reconfiguration mechanisms available at optical frequencies, using nonvolatile phase change materials is one of the most prominent. Tuning the refractive index of these materials, and thus changing the electromagnetic response of the device, can be achieved by external modulation that enables the transition between their amorphous and crystalline structural states. In this work, we study a structure that exploits these materials to fully control the electromagnetic response (i.e., electric, magnetic, and electromagnetic coupling). Powered by this controllability, we present how the metasurface can be designed to perform beam-steering and switchable one-way absorption applications. In addition, we demonstrate that the same platform can be designed to work in a nonlocal regime to implement a more efficient way of controlling light direction.