Abstract
The effect of well and barrier widths on optical properties of intersubband transitions in asymmetric (CdS/ZnSe) quantum wells have been investigated theoretically. The electronic states in these structures are calculated using both the envelope wave function approximation and the compact-density matrix formalism. The obtained results reveal that the linear and nonlinear properties have non-monotonic behavior with these parameters. It is found that the optical absorption and the refractive index change are greater in asymmetric double quantum well than that of symmetric heterostructure. These results suggest that the absorption process can be easily controlled by the structure parameters of an asymmetric rectangular quantum well. Thus, our results can be useful for electro-optical modulators and photodetectors in the infrared region. (C) 2013 Elsevier GmbH. All rights reserved.