Processing High Permittivity TiO2 for All-Dielectric Metamaterials Applications at Terahertz Frequencies

High permittivityHigh Permittivity TiO2 ceramic for the realization of All-Dielectric MetamaterialsMetamaterials operating at terahertzTerahertz frequencies was processed. Samples of bulk TiO2 ceramic were shaped from different grain size powders and Spark PlasmaPlasma Discharge Sintering was compared with conventional sintering. Then, the samples were characterized in the 0.3–1.4 THz range by THz-Time Domain Spectroscopy. The measurements agree well with the Four Parameters Semi-Quantum model. The samples shaped by Spark Plasma Sintering exhibit the highest refractive index combined with the lowest loss, and are thus suitable to obtain the negative indexNegative Refractive Index of All-Dielectric MetamaterialsMetamaterials.