Polarization-Independent Terahertz Tunable Analog of Electromagnetically Induced Transparency

The analogs of electromagnetically induced transparency (EIT) based on the concept of metamaterials (MMs) bring the primitive quantum phenomena into the scope of classical optics. However, most of the previous designs are anisotropic. Here, in this letter, a tunable isotropic classical analog of EIT is studied based on the wide-angle MM with a layer of vanadium dioxide underneath it. The tunable conductivity of vanadium dioxide is the key point to realize the dynamic modulation of EIT. The numerical calculation tells that the transmission peak of EIT can be tuned from 66% to 12% when the conductivity of vanadium dioxide is changed from 10 to 2000 Ω-1cm-1. Furthermore, such design possesses a nearly insensitive characteristic of transmission on polarization and incident angle. Although the simple planar structure presented here is a specific design to manipulate EIT-like phenomenon in terahertz MMs, it can be easily scaled to other electromagnetic spectra. This letter could provide one possible way for the plasmonic filter and sensing application.