R. Yahiaoui

Broadband dielectric terahertz metamaterials with negative permeability

We present a design of dielectric metamaterials exhibiting a broad range of negative effective permeability in the terahertz spectral region. The investigated structures consist of an array of high-permittivity rods that exhibit a series of Mie resonances giving rise to the effective magnetic response. The spectral positions of resonances depend on the geometrical parameters of the rods and on their permittivity, which define the resonant confinement of the electromagnetic field within the rods. The electromagnetic coupling between the adjacent rods is negligible. With a suitable aspect ratio of the rods, a broadband magnetic response can be obtained.

Fishnet metamaterials on thin polymer film for terahertz applications

An original double side photolithography method on ultrathin polymer and a laser micromachining technique were used to fabricate different fishnet structures. We performed simulations and experiments by terahertz time domain spectroscopy (THz-TDS from 100GHz to 3THz) respectively. The effective parameters were extracted with a single shot approach.

Tunable metamaterials with negative permeability in THz range

We report on metamaterials which exhibit a tunable interval of negative effective permeability within 0.2–0.36 THz. They consist of a strontium titanate platelet, which shows a high and temperature tunable permittivity, with an array of laser engraved slits. The negative permeability then is due to a resonant confinement of the electromagnetic field within the rods. The range of negative permeability is determined by the geometry and the permittivity of the material used.