Intersubband optical properties of a laser-dressed asymmetric triple quantum well nanostructure

The simultaneous effect of static electric and magnetic fields as well as the intense THz laser field on the intersubband nonlinear optical properties of n-type asymmetric triple δ-doped quantum well is theoretically investigated. The calculations are carried out within the framework of the effective-mass and parabolic-band approximations, with the use of a diagonalization technique to determine the electron energies and the wave functions. The analytical expression of the total absorption coefficient and the relative refractive change of the structure have been found by using the compact-density-matrix approach via an iterative method. The obtained results show that the strengthening of the electric and the magnetic fields, as well as the increment of laser field parameter, lead to a blue shift of the resonant peaks of the intersubband optical absorption and the relative refractive index change spectrum. Additionally, the strengthening of the external fields leads to the reinforcement of the total absorption spectrum intensity. Finally, we have found that with the decrease in the number of the well, by keeping the effective width of the structure constant, the blue shift can be observed in the total absorption spectrum. Therefore, the obtained results give an additional possibility to tune the performance of new devices, based on the quantum wells nanostructures.