Experimentally measured angular dependences of the internal and external reflections of polarized radiation from a metal (gold) film on the surface of a glass semicylinder are used to calculate the refractive indices of both the semicylinder material and the metal. The results of measurements of total internal reflection are used to determine the losses of light intensity at the semicylinder surfaces and in the semicylinder material bulk. The direct and inverse photometry problems have been solved for light incident onto the gold film from both the air and the glass side. A good agreement between theoretical results and experimental data has been obtained. The issue of determination of the critical angle of the attenuated total internal reflection and the angular position of the plasmon resonance has been examined. On the basis of the results of our experimental studies, a positive answer to the fundamental issue the validity of the relativity postulate about the finiteness of the velocity of light propagation in media has been obtained.

It is shown that, under the two-photon absorption in CdS, the increase in the azimuth of polarization causes a smooth change of the large semi-axis angle rotation, ellipticity, focal parameter, and eccentricity of the polarization ellipse. When the angle of phase lag delta = 40 degrees, the minimum value of ellipticity and the maximal values of focal parameter and eccentricity will be realized.

The density of states for InAs/GaAs quantum dot (QDs) bi-layer arrays placed between two AlGaAs barriers is studied by means of photoluminescence (PL) excitation, resonant PL and time-resolved PL. By varying the excitation energy from above the AlGaAs band gap to values resonant with the QD energies, the energy of states in each layer including the wetting layer, corresponding localized states, defect states and QD states is determined. The creation of asymmetric pairs of quantum dots caused by interlayer coupling is traced starting from the case of weakly correlated systems represented by bi-layer QD arrays with a thick GaAs spacer layer (50 monolayers) to the case of fully correlated systems with a GaAs spacer (30 monolayers). Different mechanisms of carrier relaxation related to the density of states below the barrier and interlayer coupling are explored.

The method of a single light source has been used to determine the value of the two-photon absorption coefficient beta of commercial glasses with CdSxSe1-x nanocrystalline inclusions at the lasing frequency of a ruby laser. The value of beta for the system of nanocrystals in a glass matrix was found to become three orders of magnitude lower than that for bulk CdSxSe1-x single crystals. This phenomenon correlates by its order of magnitude with a reduction of the concentration of absorption centers. It has been shown that, as the energy of pump light quanta approaches the energy gap width in CdSxSe1-x, the value of beta for such systems grows more slowly than that for CdSxSe1-x single crystals. obtained with similar dependences for CdSxSe1-x single crystals.

To study the dependence of the two-photon absorption coefficient beta on a polarization azimuth phi we used the method of one light source at the ruby laser frequency. It was shown that beta changes smoothly with increasing. from zero to pi/2. The minimum value of beta was realized in the vicinity of phi=45 degrees.

Relations that describe the polarization state of a light propagating in a uniaxial dichroic single crystal have been analyzed in the case of weak absorption, when Re epsilon >> Im epsilon, epsilon being the relative dielectric permittivity of the crystal. It has been found that those relations allow the state of light polarization to be predicted in the validity range of the linear optics laws, as well as provided that saturation and two-photon absorption are in operation. It has also been shown that those relations quantitatively describe the experimentally established regularities in a variation of such parameters of the light polarization ellipse as the angle of rotation of its major semiaxis, ellipticity, focal parameter, and eccentricity.

We have investigated optical dimensional phenomena which are manifested as the thickness dependences of the indices of refraction n and absorption k and of the magnitude of the quasi‐Brewster angle of thin layers of gold. In the range of thicknesses 20 < d > 180 Å, all these phenomena have an oscillating character. Based on the earlier published experimental data on the energy coefficients of transmission T and reflection R of thin layers of atomic semiconductors (Se, Te, Ge, and Si), new calculations of the thickness dependences of n and k have been carried out without the simplifying assumptions which lead to incorrect results. The errors in determining the optical constants of thin layers from photometric data have been analyzed in detail. The causes of the earlier errors in works devoted to this kind of investigation have been established.

Photoluminescence spectroscopy is used to investigate the size distribution of InAs quantum dots embedded in GaAs quantum wells as function of substrate temperature and InAs coverage. For intermediate InAs coverage, quantum dots of more than one distinct size class coexist with each other. We show that the quantum dot size distribution is bimodal for relatively high growth temperatures (T(G)congruent to 505 degrees C) and becomes multimodal for relatively low growth temperatures (T(G)congruent to 420 degrees C) with growth interruptions. We explain this behavior in terms of two distinct thresholds for dot formation: (i) the minimum InAs coverage which can lead to islanding and (ii) the coverage consistent with the optimal dot size for the given growth conditions. Further, thermally activated electron transfer from dots in the smaller size class to those in the larger size class is investigated using the temperature dependence of the photoluminescence.

Optical methods are described for determining the parameters of semiconducting quantum dots synthesized in a glassy borosilicate matrix. The limitations of these methods and the magnitudes of their errors are analyzed. The parameters of CdSxSe1−x nanocrystals in the commercial glasses KS-10, OS-12, Corning 2–61, and other experimental samples are determined.

The analysis of the linear and nonlinear optical properties resulting from quantum confinement in CdSSe-doped glasses is reviewed. The growth technology and the data obtained by x-ray diffraction and transmission electron microscopy methods are also reviewed. Analysis of the influence of sizes, composition, and the dispersion of these values on both charge carrier energy and optical (absorption and photoluminescence) spectra is carried out. The peculiarities of the absorption saturation processes related to the quantum confinement, the surface recombination, and the hexagonality of microcrystals randomly oriented in the glass matrix are discussed.

The energy level structure of the CdSSe microcrystallites in the glass matrix has been obtained from absorption spectra. The analysis takes into account the quantum-size effect and the variation of both microcrystallite radius and composition. Peculiarities of the absorption saturation and the most promising spectral regions for the observation of optical bistability have been determined.

New concepts are developed to describe a wide area of nonlinear systems involving the phase relaxation peculiarities for the degenerate two-level system under the resonant optical excitation. Nonlinear susceptibility of the two-level system becomes anisotropic, and self-induced changes of polarization (SICP) are developed to the large (gigantic) magnitudes. The nonlinearities of two different natures are considered: the saturation of absorption and the resonant optical reorientation of anisotropic defects. For these particular cases, the SICP effects manifest themselves at a field much lower than that in traditional nonlinear optics. The larger magnitudes of the effects offer good possibilities for the development of optical devices based on the new physical principles. Various applications of SICP effects are demonstrated, including the spectroscopic investigations of impure cubic crystals, optical diagnostics, optical storage, information processing, and the development of new optical devices.

The methods of linear and nonlinear optics were used in an investigation of the influence of deviations from stoichiometry on the Urbach part of the edge absorption in CdSe. It was established that an increase in the shallow acceptor concentration increased the smearing of the linear absorption edge, increased the bleaching threshold, and altered the absorption coefficient when the radiation intensity was increased. A comparison of the depth of shallow acceptor levels deduced from the temperature dependence of the bleaching threshold and that obtained from the luminescence and photoconductivity spectra showed that the bleaching was due to charge exchange involving acceptor levels at a depth approximately 0.1 eV. These acceptors were components of complex luminescence centers responsible for luminescence bands with maxima at h-nu(m) = 1.73 and 1.2 eV.

The investigation of the UV-light-induced defects in alkalihalide crystals with molecular ions NO − 2 has been performed in the temperature range from 4 to 300 K. As a result we obtain the characteristic changes of electronic absorption band of NO − 2 - ion after uv-light irradiation at 4,2 K. The experiments is obtained that the new continuous band is connected with the V K -center which is created effectively in the alkali-halide crystals with molecular ions NO − 2 by UV-irradiation.