Electrooptical Properties of Cylindrical Quantum Dots

We show how to compute the optical functions (the complex electrosusceptibility tensor, dielectric tensor, electroreflection spectra) for semiconductor quantum dots exposed to a uniform static electric field in the growth direction, including the excitonic effects. The method uses the microscopic calculation of the quantum dot excitonic wave functions and energy levels, and the macroscopic real density matrix approach to compute the electromagnetic fields and susceptibilities. The electron-hole screened Coulomb potential is adapted and the valence band structure is taken into account in the cylindrical approximation, thus separating light-and heavy-hole motions. In the microscopic calculations, using the effective-mass approximation, we solve the 6-dimensional two-particle Schrödinger equation by transforming it into an infinite set of coupled second order 2-dimensional differential equations with the appropriate boundary conditions. These differential equations are solved numerically giving the eigenfunctions and the energy eigenvalues. Having them, we can compute the quantum dot electrooptical functions. Numerical calculations have been performed for an InGaAs quantum dot with a constant electric field applied in the growth direction. A good agreement with experiment is obtained

Optical Anisotropy of Quantum Disks in the External Static Magnetic Field

We show how to compute the optical functions (the complex magneto-susceptibility, dielectric function, magneto-reflection and ellipsometric spectra) for semiconductor quantum disks exposed to a uniform magnetic field in the growth direction, including the excitonic effects. The optical response is calculated for an oblique incidence of the propagating electromagnetic wave and for input waves with different polarization. The method uses the microscopic calculation of nanostructure excitonic wave functions and energy levels, and the macroscopic real density matrix approach to compute the electromagnetic fields and susceptibilities. The electron-hole screened Coulomb potential is adapted and the valence band structure is taken into account in the cylindrical approximation, thus separating light- and heavy-hole motions. The novelty of our approach is that the solution is obtained in terms of known one-particle electron and hole eigenfunctions, since, in the considered nanostructure due to confinement effects accompanied by the e-h Coulomb interaction, the separation of the relative- and center-of-mass motion is not possible. We obtain both the eigenvalues and the eigenfunctions. The convergence of the proposed method is examined. We calculate the magnetooptical functions, including the optical Stokes parameters and ellipsometric functions for the case of oblique incidence. Numerical calculations were performed for InAs (disk)/ GaAs (barrier) disks. A good agreement with experiments was obtained

Determination of SLR station coordinates and velocities based on laser observations of low satellites

W pracy przedstawiono wyniki wyznaczania orbit trzech niskich satelitów Ajisai, Starlette i Stella na podstawie obserwacji laserowych 14 stacji SLR wykonanych w latach 2001-2005. Ponadto wyznaczono geocentryczne i topocentryczne współrzędne oraz prędkości w płaszczyźnie horyzontu i przestrzeni 3D czterech stacji Yarragadee (7090), Greenbelt (7105), Graz (7839) i Herstmonceux (7840). Otrzymane wyniki porównano z wynikami otrzymanymi dla satelitów LAGEOS, układu ITRF2005 oraz dla modelu geologicznego NNR-NUVEL1A. Wszystkie obliczenia przeprowadzono w oparciu o model pola grawitacyjnego Ziemi EIGEN-GRACE02S. Przedstawione rezultaty pokazują, że wyniki obserwacji laserowych niskich satelitów takich jak Ajisai, Starlette, Stella mogą być z powodzeniem wykorzystane do wyznaczania współrzędnych i prędkości stacji SLR.In this work, the results of satellites orbit determination of three low satellites Ajisai, Starlette, and Stella on the laser observations of 14 SLR stations performed in the years 2001-2005 were presented. The geocentric and topocentric positions and velocities in horizontal plane and in 3-D space of four stations Yarragadee (7090), Greenbelt (7105), Graz (7839), and Herstmonceux (7840) were determined. The received results were compared with the results obtained for LAGEOS and with the ITRF2005 and the geological model NNR-NUVEL1A. All calculations have been made assuming the model of the Earth gravity field EIGEN-GRACE02S. The results presented in this work show that the laser data of low satellites such as Ajisai, Starlette or Stella can be successfully applied for determination of the SLR station positions and velocities

Electrooptical Properties of Cylindrical Quantum Dots

We show how to compute the optical functions (the complex electrosusceptibility tensor, dielectric tensor, electroreflection spectra) for semiconductor quantum dots exposed to a uniform static electric field in the growth direction, including the excitonic effects. The method uses the microscopic calculation of the quantum dot excitonic wave functions and energy levels, and the macroscopic real density matrix approach to compute the electromagnetic fields and susceptibilities. The electron-hole screened Coulomb potential is adapted and the valence band structure is taken into account in the cylindrical approximation, thus separating light- and heavy-hole motions. In the microscopic calculations, using the effective-mass approximation, we solve the 6-dimensional two-particle Schrödinger equation by transforming it into an infinite set of coupled second order 2-dimensional differential equations with the appropriate boundary conditions. These differential equations are solved numerically giving the eigenfunctions and the energy eigenvalues. Having them, we can compute the quantum dot electrooptical functions. Numerical calculations have been performed for an InGaAs quantum dot with a constant electric field applied in the growth direction. A good agreement with experiment is obtained

Excitonic Magnetoabsorption of Cylindrical Quantum Disks

We show how to compute the optical functions (the complex magnetosusceptibility, dielectric function, magnetoreflection) for semiconductor quantum disks exposed to a uniform magnetic field in the growth direction, including the excitonic effects. The method uses the microscopic calculation of nanostructure excitonic wave functions and energy levels, and the macroscopic real density matrix approach to compute the electromagnetic fields and susceptibilities. The electron-hole screened Coulomb potential is adapted and the valence band structure is taken into account in the cylindrical approximation, thus separating light- and heavy-hole motions. The confinement potentials are taken as step-like both in the z and in-plane directions. Numerical calculations have been performed for $In_{0.55}Al_{0.45}As$ (disk)/$Al_{0.35}Ga_{0.65}As$ (barrier) and InP/GaP disks and the results are in a good agreement with the available experimental data

Electrooptical Properties of Cylindrical Quantum Dots

We show how to compute the optical functions (the complex electrosusceptibility tensor, dielectric tensor, electroreflection spectra) for semiconductor quantum dots exposed to a uniform static electric field in the growth direction, including the excitonic effects. The method uses the microscopic calculation of the quantum dot excitonic wave functions and energy levels, and the macroscopic real density matrix approach to compute the electromagnetic fields and susceptibilities. The electron-hole screened Coulomb potential is adapted and the valence band structure is taken into account in the cylindrical approximation, thus separating light- and heavy-hole motions. In the microscopic calculations, using the effective-mass approximation, we solve the 6-dimensional two-particle Schrödinger equation by transforming it into an infinite set of coupled second order 2-dimensional differential equations with the appropriate boundary conditions. These differential equations are solved numerically giving the eigenfunctions and the energy eigenvalues. Having them, we can compute the quantum dot electrooptical functions. Numerical calculations have been performed for an InGaAs quantum dot with a constant electric field applied in the growth direction. A good agreement with experiment is obtained

Excitonic Magnetoabsorption of Cylindrical Quantum Disks

We show how to compute the optical functions (the complex magnetosusceptibility, dielectric function, magnetoreflection) for semiconductor quantum disks exposed to a uniform magnetic field in the growth direction, including the excitonic effects. The method uses the microscopic calculation of nanostructure excitonic wave functions and energy levels, and the macroscopic real density matrix approach to compute the electromagnetic fields and susceptibilities. The electron-hole screened Coulomb potential is adapted and the valence band structure is taken into account in the cylindrical approximation, thus separating light- and heavy-hole motions. The confinement potentials are taken as step-like both in the z and in-plane directions. Numerical calculations have been performed for $In_{0.55}Al_{0.45}As$ (disk)/$Al_{0.35}Ga_{0.65}As$ (barrier) and InP/GaP disks and the results are in a good agreement with the available experimental data

Electro-Optical Properties of II-VI Superlattices

We show how to compute electro-optical spectra of semiconductor superlattices in the region of interband electronic transitions. The method uses the microscopic calculation of eigenvalues and eigenfunctions and the macroscopic real density matrix approach to compute the electromagnetic fields and susceptibilities. The electron-hole screened Coulomb potential is adapted and the valence band structure is taken into account in the cylindrical approximation, thus separating light- and heavy-hole motions. We calculate the electro-optical functions, including the optical Stokes parameters and ellipsometric functions for the case of oblique incidence. Results are given for Zn$\text{}_{1-x}$Cd$\text{}_{x}$Se/ZnSe superlattices and a good agreement with experiments is obtained

MULTIPOLARITONS IN SEMICONDUCTOR THIN-LAYERS - INTERFERENCE EFFECTS IN THE REFLECTANCE SPECTRA

We consider the case of a plurality of polariton modes due to the valence band structure, and give a one-dimensional model to compute the optical functions in the exciton frequency range. Interference effects of each mode with itself and with the other modes are identified by a fine structure in the reflectivity spectrum