Central cell correction, pressure and temperature effects on the nonlinear optical rectification and second harmonic generation in a doped GaAs/GaAlAs multi-layer quantum disk

Using the effective mass approximation, we investigate electron states in $GaAs/{Al}_x{Ga}_{1-x}As$ core/shell MSQDs, assessing the effects of hydrostatic pressure (P) and temperature (T) on band structure and wave functions. Additionally, we examine the influence of central cell correction, pressure, and temperature on second harmonic generation (SHG) and nonlinear optical rectification (NOR). Our findings indicate that external pressure causes a decrease in energy levels, leading to a redshift in the peak positions of SHG and NOR, while external temperature increases energy levels, resulting in a blueshift. Pressure also enhances the peak intensity of SHG and NOR. However, when the pressure exceeds $20\text{Kbar}$, the peak magnitude begins to decrease. Temperature, on the other hand, consistently diminishes the peak intensity. Additionally, we have discovered that both NOR and SHG can be significantly improved by selecting the appropriate type of impurities. This study highlights the potential for optimizing nonlinear optical properties through external stimuli in MSQDs, enabling new designs for photonic devices.