Search

WOS: 000357141400031, In this study, the intersubband optical absorption coefficients and the refractive index changes are calculated in a square quantum well (SQW), a parabolic quantum well (PQW), a graded quantum well (GQW) and a V-shaped quantum well (VQW), without and with the intense laser field (ILF). Our results show that the position and the magnitude of the linear, nonlinear and total absorption coefficients and refractive index changes depend on ILF parameter and the quantum well (QW) shape. While for SQW the intersubband absorption spectrum shows blue shift up to the critical ILF value, this spectrum shows red shift for greater ILF values than this certain value. Whereas, for PQW, GQW and VQW the absorption spectrum shows always red shift by increasing ILF. Thus, the intersubband absorption coefficients and the refractive index changes which can be suitable for great performance optical modulators and multiple infrared optical device applications can be easily obtained by tuning ILF value and QW shape. (C) 2015 Elsevier Ltd. All rights reserved.

WOS: 000330821200064, In this study, both the intersubband optical absorption coefficients and the refractive index changes as dependent on the magnetic field are calculated in a parabolic (PQW) and an inverse parabolic quantum well (IPQW) for different Al concentrations at the well center. Our results show that the position and the magnitude of the linear, nonlinear and total absorption coefficients and refractive index changes depend on the magnetic field strength and the Al concentration at the well center. By decreasing the Al concentration at the well center we can obtain a red shift and a blue shift in the intersubband optical transitions for PQWs and IPQWs, respectively. Thus, the absorption coefficients and the refractive index changes which can be suitable for great performance optical modulators and multiple infrared optical device applications can be easily obtained by tuning the applicable magnetic field value and the Al concentration at the well center. (C) 2013 Elsevier B.V. All rights reserved.

WOS: 000313393300007, In this study, the effects of hydrostatic pressure and temperature on the linear and nonlinear intersubband transitions and the refractive index changes in the conduction band of square and graded quantum well (QW) are theoretically calculated within the framework of effective mass approximation. Results obtained show that the energy levels in different QWs and intersubband properties can be modified and controlled by the hydrostatic pressure and temperature. The modulation of the absorption coefficients and the refractive index changes which can be suitable for good performance optical modulators and various infrared optical device applications can be easily obtained by tuning the temperature and the hydrostatic pressure. (c) 2012 Elsevier B.V. All rights reserved.