Evaluation of second harmonic generation susceptibility in a delta-doped AlGaAs/GaAs asymmetric Gaussian potential

Abstract

Second harmonic generation (SHG) susceptibility has been theoretically studied in a delta-doped asymmetric Gaussian potential quantum well. Electron structure parameters have been obtained by solving, self-consistently, the one-dimensional coupled Schrödinger-Poisson equations. Using the new expression of the second order susceptibility in a two-level system developed in our previous works, the effects of external fields (electric, magnetic and intense laser) and the well structure’s parameters (width and depth) on the SHG susceptibility have been studied. Results show that the resonant peaks of SHG attributed to the real and virtual transitions between the two lowest energy levels depend strongly on these parameters. The magnitude of the resonant peaks and their positions can be tuned by optimizing these parameters. Furthermore, the delta-doping effect in terms of concentration and location, on the SHG susceptibility, has been investigated. Results show that the delta-doping design of the structure has a significant impact on the magnitude and the position of the resonant peaks. We hope that the new and reliable results of this work will help understand the field of nonlinear optics.