Intersubband resonant enhancement of the nonlinear optical properties in asymmetric (CdS/ZnSe)/X-BeTe based quantum wells

The linear and nonlinear optical properties in asymmetric quantum wells, especially the second-harmonic generation susceptibility, the optical absorption and the refractive index change are investigated numerically for (CdS/ZnSe)/BeTe materials. The energy eigenvalues and their corresponding eigenfunctions are obtained numerically by solving the Schrodinger equation. The optical properties are calculated within the framework of the density matrix formalism. Various values of the doping density and the optical intensity on the nonlinear optical properties are considered in the calculations. Numerical results on typical CdS/ZnSe materials reveal a resonant enhancement of the second harmonic generation and the third-order optical nonlinearities. Our calculations show that results done for band alignment relative to X-BeTe conduction band minimum are extremely improved in comparison with those done for Gamma-minimum. (c) 2012 Elsevier B.V. All rights reserved.