Ricerc@Sapienza

We investigated a metamaterial composed by silicon carbide (SiC) subwavelength oriented wires, onto silicon substrate in the mid- to long- infrared range. A simple but versatile method was developed and implemented, combining homogenization techniques with the transfer matrix method for birefringent layered materials to model an effective medium layer where different inclusions content (filling factor) as well as different shape and orientation of inclusions (depolarization factors) are taken into account.

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.

In recent years, much effort has been expended upon managing and tuning the radiative properties of structures and material surfaces in the infrared (IR) wavelength range for several applications, such as thermal radiation control as well as IR sensing. Metamaterials are artificial electromagnetic materials, composed by periodically or randomly arranged, subwavelength elements.