Terahertz transmission of square-particle and rod structured TbFeO3 metamaterials

We investigated terahertz (THz) transmission of square-particle and rod structured TbFeO3 metamaterials. Mie-type resonances were excited in TbFeO3-based metamaterials. And their dependence on shape and orientation angle was studied. Dielectric TbFeO3 ceramic wafers, which were prepared by 3-D direct writing technology and traditional solid-state sintering method, were processed into square-particle and rod structured metamaterials using laser beam machining. With variation of orientation angle, square-particle structured metamaterial showed angle-independence, while rod structured metamaterial showed complicated behaviors: angle-dependence at lower frequencies and angle-independence at higher frequencies. Circular magnetic and electric field distributions surrounding the incident electromagnetic fields endowed resonances insensitivity to orientation angle. And angle-dependence of rod-shaped metamaterial at lower frequencies were caused by the central symmetry breaking.