In this study, we have investigated the influence of an external electric field on the electronic properties of the ground and excited states and studied the linear and the third-order nonlinear optical properties (i.e., absorption coefficients and refractive indices) in a spherical semiconductor quantum dot of a parabolic confinement with an on-center shallow hydrogenic impurity. In the calculations, a variational procedure was employed within the effective-mass approximation. We found that the binding energies of the ground and excited states, the absorption coefficients, and the refractive index changes of 0s-1p and 1p-2d transitions depend on the applied electric field. The results show that the existence of the electric field has great influence on the optical absorption coefficients and the refractive index changes. Also, we have found that the magnitudes of the absorption coefficient and the refractive index change of the spherical quantum dot increase for transitions between higher levels.

A detailed investigation of the optical properties of a spherical quantum dot (QD) containing one and two electrons has been performed for cases with and without a hydrogenic impurity. First, the photoionization cross section of both $D^0$ and $D^{-}$ impurities in the QD has been calculated for an on-center impurity. Second, the intersublevel optical absorption and oscillator strength between the ground and excited states have been examined based on the computed energies and wave functions. The full numeric matrix diagonalization technique has been employed in determining sublevel energy eigenvalues and their wave functions. The Poisson-Schrödinger equations have been solved self-consistently in the Hartree approximation. In addition, quantum-mechanical many-body effects have been investigated in the local density approximation. The results are presented as a function of quantum dot radii and photon energies.

The authors investigate the multiple confined modes of GaAs $L3$ photonic crystal air-bridge cavities, using single layers of InAs quantum dots as active internal light sources. Theoretical results for the energies, quality factors, and emission polarizations of the first five modes are compared to experimental data for cavities with lattice periods ranging from $240\text{to}270\mathrm{nm}$ . The authors also present in-plane field distributions for each mode. In addition to the well-known quality factor improvement of the fundamental mode, they show that outward displacement of the end-holes selectively redshifts modes with large end-hole-field overlaps, thus reordering the modes.

In this study, a detailed investigation of the nonlinear optical properties of a spherical quantum dot (QD) containing one and two electrons has been carried out. First, intersublevel linear, third-order, and total absorptions of both single- and double-electron QDs have been investigated for cases with (i.e., $D^0$ and $D^{-}$ donor) and without impurity. Second, linear, third-order, and total refractive indices have been examined in the same structure. In the calculation of optical properties, for the density of electrons in the QD considered, some symbolic values chosen are not similar to those in previous studies. The full numeric matrix diagonalization technique has been employed in determining sublevel energy eigenvalues and their wave functions. The Poisson–Schrödinger equations have been solved self-consistently in the Hartree approximation. In addition, the quantum mechanical many-body effects have been taken into account in local density approximation. The results are presented as a function of QD radii, photon intensities, and photon energies. It is found out that although magnitudes of the linear absorption coefficients are the same for cases with and without impurity, the third-order ones are larger, and so the total absorption coefficients are smaller in the case without impurity. It is also observed that the size of the QD and the intensity of the illumination have drastic effects on nonlinear optical properties.

In this study, we have investigated the inter-sublevel optical properties of a core/shell/well/shell spherical quantum dot (QD) with the form of quantum dot-quantum well heterostructure. In order to determine the energy eigenvalues and corresponding wave functions, the Schrödinger equation has been solved full numerically by using shooting method in the effective mass approximation for a finite confining potential. The inter-sublevel optical absorption and the oscillator strength between ground (1 s) and excited (1 p) states have been examined based on the computed energies and wave functions. Also, the effect of a hydrogenic donor impurity, located at the center of the multi-shell spherical quantum dot (MSQD), has been researched for different core radii (R1), shell thicknesses (Ts), and well widths (Tw) in certain potential. It is observed that the oscillator strengths and the absorption coefficients are strongly depend on the core radii and layer thicknesses of the MSQD.