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Photonic metamaterials consisting of artificial opal with magnetic inclusions were considered, used in controllable microwave electronic devices. The analyzed structures consist of matrices of SiO2 nanospheres (diameter 200 - 400 nm) with included clusters of ferrite spinels (MnxCo0.6-xZn0.4Fe2O4, NixCo0.6-xZn0.4Fe2O4, LaxCo0.6-xZn0.4Fe2O4, NdxCo0.6-xZn0.4Fe2O4) in interspherical nanospacing (4 ÷ 7% concentration). The ellipsoidal clusters are polycrystalline, with spatial dimensions of 20 – 30 nm and grains of 5 – 12 nm. A controlled wave absorption was obtained in these high inductivity structures. Evolution of the wave attenuation coefficient, α[dB/m], in function of the applied magnetic field and particle inclusion size, for different content of the magnetic ions in the ferrite inclusion, have been determined at frequencies around the samples ferromagnetic resonance, by structural simulation. The test configuration was: sample inside the rectangular waveguide, mode TE10, in the frequency range 24 ÷ 40 GHz. The polarizing magnetic field for the ferrites was tested in the range of 0 ÷ 20 kOe and minimized by modifying the structure. The metamaterial design optimization was realized, controllable by different parameters at structure level. The ferromagnetic resonance influence on the control process was pointed out and also the particular results and effects which can be induced by the resonant behavior.

Tunable transmission and absorption coefficients in visible and infrared range have been obtained for metamaterial filters with a structure of metal on dielectric nanocomponents. Materials were stacks of nanoconstituents placed in alternate layers, which present a maximum or a minimum of the transmission coefficient and convenient values of the absorption coefficient when the periodicity is interrupted in a controlled manner. A simulational set-up with the metamaterial sample in a channel waveguide was conceived for obtaining the S parameters at the field propagation, using the HFSS program. The plasmon dispersion at the metal / dielectric interface was taken into account for calculating the frequency dependent surface plasmon wave vector, which can be adjusted by modifying the refractive index and the electric permittivities of the constituents. Transmission coefficients have been calculated for different structure geometries. The optimal metamaterial configurations have been chosen, in function of the desired filtering effect, for a range of incident field wavelength of 600 – 900 nm. A transmission variation of about 50 … 80 % at the central frequency, in comparison with the transmission effects in the side bands has been demonstrated for the proposed metamaterial filters.

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Using of the metamaterials improves the sensitivity and resolution of sensor devices, having multiple applications in biomedicine (imaging, biomarkers, telemedicine, etc.). We have studied the effect of different types of ordering in the lattices of nanostructures inside the metamaterial samples. Structures consisting of metallic atoms (tens of nanometers diameter) arranged relative periodically in a dense dielectric matrix have been analyzed by simulation methods. We have focused on the opto-electronic coupling phenomena and the interactions between plasmons and the applied field. A study of the electron scattering processes was performed, the simulational data being used to calculate the reflectance and permittivity in function of the wavelength, in the range of 500…2300 nm. The electromagnetic properties of the metamaterial samples depending on particles shape, dimensions and on the reports between metallic inclusions dimensions and the dimensions of the dielectric matrix where are included have been studied and new configurations were proposed in order to improve the metamaterial sensors performance. We expect an increment in the response to the exciting field of about 7%, in a more dense state of spins characterising the new material samples.