Phase-Controlling Infrared Thermal Emitting Metasurfaces

We have shown, using analytical expressions and numerical simulations, that metasurfaces can have multiple functionalities, namely that they can impart a controlled phase difference between cross-polarized circular reflected and transmitted fields, having at the same time a non-vanishing absorption in the near-infrared region, at resonant wavelengths determined by the geometry of the metasurface. Because the optical absorptivity of the metasurface determines its thermal emissivity, and thus the coherence properties and propagation directionality of light sources, the same metasurfaces can act as lenses, for instance, and as thermal emitters.