Analysis of a Metamaterial based Reflective Filter at Mid-IR frequencies

In this paper, we design and theoretically investigate a tunable and compact reflective filter in graphene based hyperbolic metamaterials. Using an effective medium theory and a transfer matrix approach, we calculate the reflectance characteristics at mid-infrared frequencies. Our theoretical analysis shows that by changing the chemical potential of the graphene, the reflectance spectra of the filter can be shifted to the shorter wavelengths. We also show that for a fixed chemical potential, the reflectance spectra of the filter can be further blue-shifted by increasing the number of graphene monolayers. Interestingly, we find that the reflectance is almost independent of the angle of incident and polarization (TE/TM) of the incoming waves. We believe that our proposed metamaterial based filter could be a potential candidate for developing tunable filters and switches.