Yoğun lazer alanının kuantum noktalarında altbantlararası geçişlere ve safsızlık bağlanma enerjisine etkileri

In this thesis, we focus on the effects of non-resonant, high-frequency intense laser field (ILF) on the optical response of a two-dimensional quantum dot including on-center impurity under uniform magnetic field. THz laser radiation with circular polarization has been treated within the framework of high-frequency Floquet approach. The effects of impurity types modeled by using different potentials such as Gaussian, Hydrogenic and screened Coulomb on the system are investigated. Besides, we have also examined the influence of ILF on the optical properties of a two-dimensional quantum ring described by the parabolic confinement potential and the Gaussian peak localized to the center. Based on the compact-density matrix approach and iterative procedure, linear and third-order nonlinear optical absorption coefficients and refractive index changes and third-harmonic generation coefficient are calculated. The energy eigenvalues and wave functions of defined systems have been obtained numerically by using finite element method in one dimension which is based on Galerkin approach. The obtained results show that the action of ILF leads to crucial changes in the electronic structure of quantum dot (ring), the impurity binding energy and consequently the behavior of optical properties. Further, the position and magnitude of the resonant peak of optical characteristics are significantly affected by magnetic field, quantum dot (ring) size, the impurity potential parameters and the system parameters.