Mode Integration Disorder Metamaterials: Electromagnetic Wave Manipulation From Arbitrary Coupled Modes to Single Mode

ABSTRACT Disordered metamaterials, characterized by both the disordered configurations of individual meta‐cells and their irregular spatial arrangements, represent a novel class of metamaterials. Such structural disorder endows them with distinctive electromagnetic properties, enabling the manipulation of nonuniform electromagnetic waves composed of multiple coupled modes. In this study, we investigate the capability of disordered metamaterials to convert arbitrary multimode inputs into a single‐mode output, termed mode integration. By analyzing the scattering behavior of these metamaterials, we formulate matrix‐based scattering parameters that describe their electromagnetic responses under coupled‐mode excitation, and identify specific features of these parameters that signify mode‐integration capability. To design disordered metamaterial structures that satisfy the desired scattering characteristics, we first induce output fields containing the target mode using randomly generated disordered structures. Then, by concatenating multiple disordered structures, the unwanted modal components are progressively suppressed, yielding a single‐mode output. Using a genetic algorithm, scattering matrices meeting the target criteria can be efficiently assembled from a predefined database of random disordered structures. Finally, full‐wave simulations of the designed structure under different excitation modes provide detailed insight into the modal evolution along the propagation direction, clearly demonstrating the successful integration of arbitrary coupled modes into a single target mode.