Nonlinear absorption coefficient and relative refractive index change for Konwent potential quantum well as a function of intense laser field effect

Abstract

Optoelectronic properties of semiconductor quantum wells are among the most studied issues in solid state device physics. However, this is a topic that deserves attention because of the particular potential energy shape which can consider important physical facts such as impurity diffusion, in combination with external factors such as electromagnetic fields or intense laser field effects, allowing to investigate of new possible behaviors for the optical properties of interest. In this line, we consider an GaAs/Al𝑥����Ga1−𝑥����As heterostructure with its conduction band profile described by the so-called Konwent potential which, as a function of the chosen parameters, can generate a single or double quantum well, shaped through aluminum concentration. We compute the corresponding electronic structure by working within the effective mass approximation and solving the one-electron Schrödinger equation. In accordance, we report the absorption coefficient and the relative refractive index change for the system as a function of Konwent potential parameters. Then, for a fixed set these quantities defining a quantum well shape, we investigate the effect of an electric field applied along the confinement direction (𝑧����), as well as an in-plane (𝑥����-directed) constant magnetic field. Finally, we investigate also the influence of a non-resonant intense laser field effect on the system. Here we can conclude that the Konwent potential parameters allow to tune the optical properties for energies ranging from 20 up to 100 meV; that the electric field induces a blue-shift, and a diminishing of the intensity, for the optical response; that the magnetic field also induces a small blue-shift, but practically without intensity lost; and that the intense laser field also causes a stronger blue-shift, together with an increase in the optical response.