Metasurface-bounded open cavities supporting virtual absorption: free-space energy accumulation in lossless systems

Opt Lett. 2020 Jun 1;45(11):3147-3150. doi: 10.1364/OL.389389.

Abstract

We investigate an anomalous scattering phenomenon exhibited by a lossless system based on metasurfaces. Electromagnetic energy is neither reflected nor transmitted but stored within the system to be available again at a different time. We analytically derive the proper excitation conditions and verify the response of the system through a proper set of full-wave simulations, demonstrating the key role of the metasurface in enabling such a zero-scattering condition. The practical feasibility and the opportunities offered by the proposed metasurface-based system may open the door to the design of virtual absorbers with dynamic properties in energy absorbing, storing, and releasing.