Numerical analysis of Bragg reflection spectra of GaAs/AlGaAs super-layers depending on hydrostatic pressure

We have examined the effect of hydrostatic pressure on the reflection in a heterostructure composed of \(N\) $N$ multiple quantum wells. The super-cellular structure is formed of a GaAs-based quantum well (QW) sandwiched by relatively thin Al_xGa_1−xAs barriers with a high \(x=74\%\) $x=74\%$ Al content. We evaluated the effect of changing the number of quantum wells on reflection and calculate the theoretical transition energies for different excitons in the sample. Bragg resonance was tuned and satisfied for normal light incidence, with photon energy equal to the energy of heavy hole excitons at the second level of quantum confinement in quantum wells. Our results show that, due to the interference with light reflected from the bottom, the resonant part is slightly distorted from the Lorentzian form. Besides increasing the number of wells \(N\) $N$ , the resonant part is different from the Lorentzian form. Since the resonance, the levels of the different QW are electronically isolated. This spectral evolution is entirely due to the dependence of the radiative correction, which becomes more and more important as \(N\) $N$ increases. Under the effect of pressure, the reflection coefficient moves toward the high frequencies and we showed its effect on interband transitions. These optical properties also depend on the dopant concentration ratio and the quantum well width.