The optical properties of an exciton trapped by an ionized donor in an ellipsoidal quantum dot (QD) with both oblate and prolate shapes under applied electric field and hydrostatic pressure have been studied. We have calculated the linear and third-order nonlinear absorption coefficients (ACs) and refractive index changes (RICs) by using a variational method within the perturbation theory. The results show that the QD shape and size have a significant influence on the positions and magnitudes of the peaks of the (ACs) and RICs, moreover, the influence of hydrostatic pressure and electric field under different QD shape is also different.
In the present paper, the optical properties of a GaAs wedge-shaped quantum dot (QD) under the effect of Rashba spin–orbit interaction (SOI) are theoretically studied. For this purpose, we have used analytical expressions for optical properties obtained by the compact-density matrix formalism. The dependence of the optical absorption coefficients and refractive index changes on the strength of Rashba SOI for different angles and different radii of wedge-shaped QD has been studied. According to the obtained results, it is found that (i) the Rashba SOI does not have considerable effects on the refractive index changes maxima. (ii) The total absorption coefficient is increased and shifted towards higher energies with considering the Rashba SOI. (iii) The influence of Rashba SOI on the optical properties depends on the parameters such as apex angle and radius of the wedge-shaped QD.