The nonlinear second harmonic generation and third harmonic generation in GaAs/GaAlAs exponentially confined quantum well: Electric and magnetic field effects

The second harmonic generation(SHG) and third harmonic generation(THG) of a GaAs/GaAlAs exponential quantum well(QW) are numerically investigated in the presence of applied electric and magnetic field, which are parallel to the QW growth direction. The eigenvalues and corresponding eigenfunctions of the system are obtained by using the finite difference technique . The expression for the second- and third-order susceptibility is given by the density matrix and iterative approach. It is showed that, the SHG and THG not only depend strongly on quantum confinement, but also the intensity of external fields. We have systematically studied the SHG and THG of different confinement QWs by adjusting the structural parameters, as well as the effects of external electric and magnetic fields. We give the optimal system parameters in which the external field effects play important role.