Conduction band non-parabolicity effect on the optical absorption coefficient and refractive index changes of spherical quantum dots

Optical absorption coefficients and refractive index changes associated with intersubband transition in typical GaAs/Al_xGa_1−xAs spherical quantum dots are theoretically investigated, both in the presence and in the absence of the conduction band non-parabolicity effect. In this regard, the effect of band non-parabolicity on the eigenvalues and eigenfunctions of the dot has been performed using the Luttinger-Kohn effective mass equation. Also, by means of the compact-density-matrix approach the linear and nonlinear optical absorption coefficients and refractive index changes have been calculated. The results show that magnitudes of these quantities are decreased and the peaks are shifted to the lower energies as the influence of band non-parabolicity is considered.