Standard optical lithography relying on clean room and microelectronic facilities is used to fabricate a thin-flexible metamaterial absorber, designed to operate at submillimeter wavelengths over the 0.1–1 THz frequency band. Large terahertz absorption has been demonstrated numerically and through experimental measurements with a maximum level of about 80%. We put emphasis in this present work on the use of single-sized “meta-cells” to achieve multiple absorption peaks. Furthermore, the use of a thin-flexible dielectric spacer makes it promising for stealth technology applications in order to disguise objects and make them less visible to radar and other detection methods.

Quasi-monodisperse dielectric particles organized in a periodic hexagonal network on an aluminum surface are exploited numerically and experimentally as a single-layered near-perfect absorber in the terahertz regime. Of particular interest are titanium dioxide (${\mathrm{TiO}}_2$) microspheres because of their large dielectric permittivity and isotropic shape leading to Mie resonances with insensitive polarization. Absorption higher than 80% at normal incidence covering two distinct ranges of frequencies is demonstrated experimentally. Furthermore, the performance of the metamaterial absorber is kept over a wide range of incident angles.

A single-sized dielectric cylinder-based metamaterial is fabricated from TiO₂ nanoparticles, using a bottom-up approach. The sub-elements constituting the metalayer are embedded in a nonmagnetic transparent host matrix in the microwave regime and arranged in a square lattice. We demonstrate numerically and experimentally a broadband magnetic activity. The key feature to achieve this performance remains in the high aspect ratio of the metamaterial building blocks. This is a very promising step towards complex electromagnetic functions, involving low-cost metamaterials with simple fabrication.

Metamaterials are artificial materials with unusual properties that do not exist in nature and basically could consist of subwavelength metallic patterns printed on dielectric substrate. In this paper, we present a theoretical and experimental investigations of metamaterials designed for THz applications. First, fishnet metamaterials which are composed with a thin dielectric material sandwiched between two metallic layers. Two techniques were used in order to fabricate our prototypes: double layer optical lithography and laser micromachining. We performed simulations and experiments using commercial software simulator based on finite element method (HFSS) and terahertz time domain spectroscopy THz- TDS respectively. A good agreement was reported between simulations and experiments while pointed out the dramatic influences of dielectric losses in the effective response.