Dual-functional multiband metasurface for efficient circular and linear dichroism

Dichroism, a significant property for manipulating and characterizing polarization states, has been extensively investigated. However, due to the inherent interdependence between linear and circular polarization, the generation of multi-band linear dichroism (LD) and circular dichroism (CD) in the same structure has proven challenging. Previous metasurfaces have only operated in a single narrow band and under oblique incidence, limiting their potential engineering applications. In this study, we propose a novel multi-band dual-functional metasurface capable of producing remarkable linear and circular dichroism in the microwave region. Importantly, these two functionalities can simultaneously be achieved under normal and oblique incident angles. Through subsequent simulations, we demonstrate that the exceptional dichroism is induced by the deliberate disruption of the structure's rotational and mirror symmetry. This multi-band and multi-functional metasurface, characterized by its simplistic geometry, is anticipated to hold great promise for various optical instruments and can find numerous potential applications.