Metasurface design by a Hopfield network: finding a customized phase response in a broadband

In this paper we proposed a metasurface design method by finding out the meta-atoms through a Hopfield network. As part of the iterative design process, since the Hopfield network is capable of filtering out unreasonable designs with no need for going through full-wave simulation, the search for meta-atom patterns is reduced and undesired results are filtered effectively. To demonstrate the validity and reliability of this method, we searched meta-atoms that can achieve customized phase profiles in a broadband for achieving two functional metasurfaces, i.e., abnormal reflection and diffusive scattering. On that basis, the generated meta-atoms compose the phase profiles of the metasurfaces. By comparing the calculated, simulated and measured results, their consistency convincingly verifies the competency of this method. More importantly, this method provides an effective phase-search strategy to obtain desired phase responses intelligently in the field of functional metasurfaces design. (paper)