Efeitos térmicos em dispositivos baseados em cristais fotônicos dielétricos

Abstract

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.