Polar metamaterials with graded air inclusions for infrared radiation managing
Polar materials, i.e. those materials where it is possible to excite the collective oscillations of the lattice ions, along with derived phononic structures offer the possibility of manipulating and amplificating IR emissivity by the excitation of such surface modes. Since the oscillation frequencies of the crystalline lattice ions are typically lower, compared to the plasma frequencies, they fall in the infrared wavelength range.