Resumo:
Metamaterials are artificially generated from natural materials, creating synthetic
structures that have distinct properties, which when combined form specific
electromagnetic properties reacting with configurable resonant frequencies within the
desired spectrum. In this work, the effect caused by temperature variation on
transmissivity was studied, observing the influence of the refractive index, resonant
frequencies and wavelengths in photonic structures composed of metamaterials, such
as photonic crystals. The thermal effects on the transmission of resonant cavities in a
one-dimensional photonic crystal were analyzed in three different cases, composed of
alternating layers of Gallium Arsite (GaAs), Silicon (Si), Bismuth-Germanium-Oxygen
(BGO) each combined with Silica (SiO2), all with SiO2 defects, considering the thermo optical coefficients and thermal expansion coefficients of the metamaterials. The
thermo-optical effects on the Photonic Band Structure (PBS) of a two-dimensional
photonic crystal with a square lattice were also investigated, in three situations with
elements composed of cylinders of BGO, GaAs and Si, all embedded in air. It was
found that the refractive index is dependent on temperature variation, and the resonant
wavelengths were changed, since thermo-optical effects affected one-dimensional
photonic structures, obtaining a transmittance efficiency greater than 85%. The results
revealed that with the increase in temperature there was a reduction in the frequencies
of the operating bands and a broadening of the prohibited photonic band in all cases
studied for two-dimensional photonic crystals.
