Wavelength selective filters using metamaterials in terahertz frequency region

Two kinds of metamaterial filters were described. First, electromagnetically induced transparency (EIT) metamaterials having EIT-like effects were experimentally demonstrated in terahertz frequency region, and their transmittance characteristics were evaluated. An EIT metamaterial consisted of a dipole resonator and a quadrupole resonator and had a gap between two resonators. At frequencies around 1.5 THz, EIT-like effects with transmittance of 82.0% were observed for EIT metamaterials with the gap distance of 3.1 μm. Second, metamaterial absorbers with various sizes were fabricated and the absorption property was measured in terahertz frequency region. 90% of absorption was experimentally obtained at 1.5 THz.