Enhanced reflective dichroism from periodic graphene ribbons via total internal reflection

A rigorous homogenization theory is developed to characterize the effective conductivity tensor of periodic graphene ribbons. This way, the obtained conductivity simplifies the study of the exotic scattering properties of periodic graphene ribbons. As a typical example, we find that the performance of reflective dichroism from the designed graphene ribbons can be enhanced (up to a maximum linear dichroism of 0.98) when the total internal reflection happens. Moreover, by rotating its optical axis, the functionality of the periodic graphene ribbon can change from an absorber for linearly polarized waves to another absorber for circularly polarized waves (maximum circular dichroism of 0.93). The revealed indispensable property of graphene ribbons in controlling the reflective dichroism indicates their promising wide applications including energy harvesting and optical sensing.