LiTaO3 based metamaterial perfect absorber for terahertz spectrum

In this article a new design of metamaterial perfect absorber (MPA) has been proposed which comprises a periodic array of LiTaO3 microcylinders grown over a silver substrate. The fundamental principle of the structure is the occurrence of Mie resonance in the cylinders due to high value of refractive index (∼10) of LiTaO3 in the wavelength range 65-100 μm. This remarkably high refractive index is a manifestation of polaritonic resonance of LiTaO3 in the considered wavelength range. The proposed structure shows high absorption coefficient in the said wavelength range with a maximum of 99.9% around 88 μm.