Transmittance spectra of (${\text{YBa}}_{{\text{2}}} {\text{Cu}}_{3} {\text{O}}_{{7 - x}}$/${\text{BaTiO}}_{3} )$ 1D photonic crystals: the role of GaAs and Al_xGa_(1−x)As semiconductors in the visible range

Abstract

We present the transmittance spectra of one-dimensional photonic crystals embedded on two sides with air. The unit cell is composed of a ${\text{YBa}}_{2} {\text{Cu}}_{3} {\text{O}}_{{7 - x}}$ superconductor as material $A$ and a ${\text{BaTiO}}_{3}$ dielectric as material ${\text{B}}$. The transmittance of the formed structure $({\text{AB}})^{N}$ was studied using the transfer matrix method for different parameters such as layer widths ($d_{{\text{A}}}$ and $d_{{\text{B}}}$), the angle of incidence, and temperature. Wavelength shifts delimiting the photonic bandgaps (PBGs) are discussed in detail. We found that these wavelengths shifted toward longer values (i.e., a redshift) as the size of the layers increased and the temperature increased. However, increasing the incidence angle shifts the wavelengths to shorter values (i.e., a blueshift). In the second part of this work, we discuss the impact of inserting semiconductor layers $\left( {{\text{GaAs}}~{\text{or}}~{\text{Al}}_{x} {\text{Ga}}_{{\left( {1 - x} \right)}} {\text{As}}} \right)$ with different bandgaps and varying the hydrostatic pressure, temperature, and aluminum concentration. We demonstrate that these semiconductors can also shift the PBGs and modify their widths; these findings constitute important results with implications for the design and realization of photonic filters.