Dual-Functional Metasurface toward Giant Linear and Circular Dichroism

As a kind of artificial surface composed of subwavelength meta-atoms, metasurface has shown great potential in full vectorial electromagnetic manipulation. Here, a dual-functional metasurface that is capable of generating 97% linear dichroism and 87% circular dichroism in the infrared region is proposed. The two functionalities can be achieved simultaneously under incident light of vertical azimuthal angles. Subsequent simulations demonstrate that the giant dichroism is induced by symmetry breaking of the structure under oblique incidence. Compared with single-functional metasurfaces, this device exhibits better performance and more functionalities without the sacrifice of compactness. It is believed that this dual-functional metasurface with simple geometry can find many potential applications in various fields, ranging from analytical chemistry and imaging to sensing and spectroscopy.