Simultaneous effects of the intense laser field and the electric field on the nonlinear optical properties in GaAs/GaAlAs quantum well

Abstract

In this study, both the linear and nonlinear intersubband optical absorption coefficients and the refractive index changes are calculated as dependent on the applied electric field (F) and the laser field intensity parameter (alpha(0)). Our results show that the location and the size of the linear and total absorption coefficients and refractive index changes depend on the applied external field effects. The shape of confined potential profile, the energy levels and the squared dipole moment matrix elements are changed as dependent on the, F and alpha(0). We have found that the intense laser field and the applied electric field can be used as a way to control the linear, nonlinear and total optical properties of the quantum well structures. While for F=0 the intersubband absorption spectrum shows blue-shift up to the critical laser field value (for about alpha(0) < L/3), this spectrum shows red-shift for laser field values greater than this certain value. In the presence F, we obtain two critical laser field values (for about alpha(0) < L/3 and alpha(0) > 2L/3). The absorption spectra display blue-shift up to the first critical laser field values, these spectra indicate red-shift up to the second critical values and show again blue-shift for the laser field values greater than these second certain values. Therefore, the variation of the absorption coefficients and refraction index changes which can be appropriate for various optical modulators and infrared optical device applications can be smooth obtained by the alteration of electric field and intense laser field. (C) 2014 Elsevier B.V. All rights reserved.