Terahertz metamaterials with dual band high refractive index

A dual band metamaterial operating in the 0 THz to 3 THz range was designed with two bands of high refractive index values. The dimension of the slab of the metamaterial is 250 μm by 250 μm and the thickness of the slab is 10 μm. Twenty five resonant metallic units were embedded in the substrate material with a gap of 0.8 um between each metallic unit. The gold metallic structure has a polyimide substrate. The return loss (S parameter) analysis showed a strong electric response and a suppressed diamagnetic response at the specific frequency range, which suggests that high values for both the dielectric constant and permeability were achieved simultaneously. The results also showed two bands of high refractive index value were observed in the particular frequency range. One peak value of the refractive index reaches 51.09 and the other peak reaches 19.72, which are much higher than the value of the pure polyimide substrate itself.