Dynamically tunable broadband mid-infrared cross polarization converter based on graphene metamaterial

We present a mid-IR highly wavelength-tunable broadband cross polarization conversion composed of a single patterned top layer with L-shaped graphene nanostructures, a dielectric spacer, and a gold plane layer. It can convert linearly polarized light to its cross polarization in the reflection mode. The polarization conversion can be dynamically tuned and realize a broadband effect by varying the Fermi energy without reoptimizing and refabricating the nanostructures. This offers a further step in developing the tunable polarizers and the polarization switchers.