Linear and nonlinear optical properties of asymmetric triple quantum wells under intense laser field

Abstract

For asymmetric triple quantum wells (ATQW) the linear and nonlinear optical absorption coefficient (OAC) and the optical refractive index change (ORIC) are analyzed according to the intense laser field (ILF). The obtained results show that the ILF parameter (alpha(0)) has an important effect on the shape and height of the confined potential profile of the ATQW, and alterations in the energy levels and the dipole moment matrix elements depend on the shape of the confinement potential. For alpha(0) = 10 nm (according to the parameters used in this study), ATQW turns into an asymmetric wider double confinement potential. As a consequence of the energy difference between the energy states, the absorption spectrum of (1-2) and (1-3) optical transitions initially shows a redshift (up to alpha(0) = 6 nm and alpha(0) = 4 nm, respectively) and then indicates a blueshift by increasing the ILF. For the (2-3) transition, the optical absorption spectrum continuously shows a blueshift and displays an oncoming shift toward the higher energies. Thus, the linear and nonlinear OAC and ORIC may be adjusted by modifying the ILF parameter. Our results are of use in the investigation into new ways of manipulating the optoelectronic properties of triple quantum well devices. Highlights The electronic and optical properties of ATQW vary with increasing ILF value. The effect of ILF on the quantum well (QW) differs depending on the shape of the QW. OAC and ORIC change with rising ILF. The absorption spectrum shows blueshifts or redshifts depending on the ILF.