Tunable terahertz metamaterials with negative permeability

Abstract

International audienceWe demonstrate experimentally and theoretically dielectric metamaterials exhibiting a tunable range of negative effective permeability in the terahertz spectral region (0.2–0.36 THz). Our structures consist of an array of intrinsically nonmagnetic rods made of an incipient ferroelectric SrTiO_3 which shows a high tunable permittivity. The magnetic response and its tuning are achieved by a temperature control of the permittivity of SrTiO_3, which defines the resonant confinement of the electromagnetic field within the rods

Metamaterials: a new frontier of science and technology

“…Different modulation approaches were demonstrated, including electrically/optically pumping the semiconductor constituent of the metamaterials, [32][33][34][35] electrocontrol of the anisotropic optical constant of liquid crystal inclusions, 36,37 external DC magnetic field tuning 38,39 and the thermal effect. 40,41 Another interesting application of metamaterials is perfect absorbers, stemming from the possibility to design metamaterial elements which can individually absorb the electric and magnetic components of incident EM waves. 42,43 …”

Variable-wavelength frequency-domain terahertz ellipsometry

“…Measurement of the complex optical properties at terahertz frequencies may further allow exploration of novel physical phenomena as observed in artificially structured metamaterials. [12][13][14] Ellipsometry is established as the preeminent method used to precisely determine the optical properties for wavelengths from the far IR ͑FIR͒ through the vacuum UV. 15,16 Ellipsometers are employed in a wide variety of applied and basic research fields because they can produce highly accurate, nondestructive measurements suitable for quantitative analysis.…”

TiO2 microsphere-based metamaterials exhibiting effective magnetic response in the terahertz regime

“…4b). We believe that magnetic resonances are excited individually within each particle forming the metamaterial and they are only weakly influenced by the mutual coupling between particles [7,16,17]. Both measured and calculated effective dielectric permittivities are rather low (Fig.…”

“…Although AD metamaterials have raised broad interests [6], only a few of them have been experimentally shown to present a magnetic resonance in the THz spectral range. For example, laser micromachining was employed to fabricate a tunable THz metamaterial made of SrTiO 3 rods [7]. The majority of other works focused on the microwave region.…”