Midinfrared Invisibility Cloak Design Using Composite Optical Materials

In this paper, conventional transformation optics is applied to design an optical cloak in mid-IR region (5 μm) for TM polarization to conceal cylindrical object using composite optical structures. Effective medium theory in this method will be used. Based on required permittivity and permeability for TM radiation, we approximate the cloak region by a 25 polymeric composite cylindrical layers. Each layer is a polymeric medium (Poly Tetra Fluor Ethylene) with random distribution of plasmonic spherical nanoparticles, which possess desired plasma frequency in order to achieve required permittivity at operational wavelength. The results show that by changing the plasma frequency of spherical particles in each layer, there is possibility of cloak design at other operational wavelengths in midinfrared range. In order to calculate the effective permittivity of each layer, Clausius–Mossotti formula is used. Based on this idea, an infrared cloak design is shown and completely simulated.