Nonlinear optical properties in AlxGa1-xAs/GaAs double-graded quantum wells: The effect of the structure parameter, static electric, and magnetic field

Abstract

We present a theoretical simulation of the impact of applied external electric and magnetic fields, as well as of the change in structure parameters, on the nonlinear optical rectification (NOR), second harmonic generation (SHG), and third harmonic generation (THG) in typical GaAs/GaAlAs asymmetric double graded quantum wells (ADGQWs). At first, we have calculated the wave functions and the subband energy levels for the lowest bounded four states confined within the structure by solving the Schr¨odinger equation using the diagonalization method within the framework of the effective mass and single parabolic band approximations. Then, analytical expressions for the NOR, SHG, and THG that arise from the compact density matrix approach are used to evaluate the corresponding coefficients. The simulation results show that the applied external fields and the structure parameters play an important role in the optical properties of ADGQWs.