External fields controlling the nonlinear optical properties of quantum cascade laser based on staircase-like quantum wells

摘要

In this paper, we present a theoretical investigation of nonlinear optical properties of Al_xGa_(1-x) As-GaAs staircase-like quantum wells heterostructure under the effects of electric, magnetic, and intense laser fields. The electronic energy levels and their corresponding wave functions are computed numerically by solving the Schrodinger equation within the effective mass approximation. The obtained results show that the applied external fields have a huge impact on the intersubband transition between the ground and the first excited levels. The optical absorption coefficient and the relative refractive index changes can be blue shifted by increasing the electric field and red shifted by increasing the intense laser field parameter. However, we can obtain either the red or the blue shift by varying the intensity of an applied magnetic field. This interesting property of the applied magnetic field can be used in the design and fabrication of optoelectronic devices based on staircase-like quantum wells and operating in the red and blue domains.