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We report the results of calculations of some optical parameters of ZnSxSe1–x thin films based on measured transmission spectra by using the Swanepoel’s method, the Wemple– DiDomenico single-oscillator model, and the Sellmeier single-oscillator model. The following optical constants have been determined: refractive index n(l),extinction coefficient k(l), the E0 parameter, dispersion parameter Ed, oscillator strength S0, real e1(l) and imaginary e2(l) parts of the dielectric constant, high-frequency dielectric constant e∞, and ratio N/m*. The obtained data are in good agreement with the data for bulk ZnSe and ZnS crystals.

A new method is proposed for the determination of the effective dielectric permittivity and magnetic permeability of a photonic crystal in a narrow frequency range near the spectral singularities at the center of the Brillouin zone. Additional conditions for the applicability of the method are discussed.

We perform numerical calculation in order to optimize the morphology of metallized ti- tania nanotubes from the point of view of flat lens application based on NIM. An efficient multiple-scattering approach is used to calculate propagation of electromagnetic waves through the materials designed. The focusing properties of a flat lens constructed from a superlattice structure of nanotube clusters were found to be better as compared to a lens with a regular arrangement of nanotubes. A disorder of 20% introduced in the position of nanotubes of the optimized superlattice does not significantly influence the focusing properties of the lens.

We propose to produce ZnO nanostructured material by thermal treatment in oxygen ambient of bulk ZnTe crystals and nanowires obtained by electrochemical treatment. Bulk ZnTe crystals are transformed into granular ZnO media by thermal treatment in a range of 700–800°C. This technology ensures a high optical quality of the produced ZnO nanostructured material to act as a gain medium for stimulated emission in the ultraviolet spectral region. The produced structures are expected to find applications in microlaser technologies for optoelectronics and photonics.

We propose to develop phosphor materials on the basis of porous alumina templates doped with rare earth elements and transition metals. This issue is especially important in connection with the development of random lasers, since the scattering properties of the porous template can de controlled by tailoring its morphology. In this work, we demonstrate that, apart from the morphology, the crystallographic structure of the template can be controlled by the conditions of post-anodization thermal treatment applied for the activation of the impurity impregnated from rare earth or transition metal containing solutions. The initially amorphous alumina structure is transformed into a γ-Al2O3 phase by annealing at 300–700°C. A δ-Al2O3 phase is predominant in samples annealed at 800–1000°C. The samples annealed at temperatures above 1100°C exhibit an α-Al2O3 structure. The technological conditions related to the solution concentration and duration of impregnation, postimpregnation annealing temperature and annealing duration were optimized from the point of view of maximum impurity ion activation.

The morphology, structural, and optical properties of porous titania layers prepared by electrochemical oxidation of Ti foils are studied as a function of technological conditions of preparation and post-electrochemical-oxidation thermal treatment. Ti foils were anodized in aqueous and non-aqueous HF and H PO solutions by applying various anodizing conditions. Titania nanotubes with diameters ranging from 30 nm to 250 nm with controlled length have been prepared. The influence of thermal treatment upon the structural properties of TiO nanotubes was investigated by means of X-ray diffraction analysis and Raman scattering. It was found that the as prepared samples are amorphous. As the annealing temperature increases to 300°C, an anatase structure is formed. Starting from 500°C, a rutile structure is produced which coexists with the anatase structure. A complete phase transition to the rutile structure occurs at 800°C. The luminescence from both anatase and rutile phases was observed at low temperatures. The origin of luminescence bands is discussed.

Rare-earth containing oxide nanocomposites are prepared of porous GaP and GaAs templates in a controlled fashion. The initial porous GaP and GaAs networks are replaced by GaPO4 and Ga2O3 structures, respectively, during annealing at emperatures from 500 to 900 o C. The impregnation of Eu and Er lanthanides from EuCl3:C2H5OH and ErCl3:C2H5OH solutions results in the formation of lanthanide containing oxide microcrystals finely dispersed into the native oxide matrix. These oxide phases are found to be EuPO4 and ErPO4 in composites obtained on GaP templates, and EuAsO4 and ErAsO4 in composites prepared on GaAs templates. 4f-4f intrashell transitions in Eu3 and Er3 ions assure strong red and green emission from these nanophases.

We report on the possibility to prepare ZnSe porous layers with different degrees of porosity by means of electrochemical methods. The prepared porous structures were characterized using scanning electron microscopy (SEM), photoluminescence (PL) and cathodoluminescence (CL) techniques. The PL of the as-grown material and porous layers measured at low temperatures (10 K) was found to be dominated by an emission band at 2.796 eV as well as a band at 2.700 eV with several phonon replicas. The analysis of the dependence of these bands upon the excitation power density and temperature suggests that free-to-bound and respectively donor-acceptor electron transitions are responsible for the emission bands involved. The comparison of SEM and CL images taken from the same porous regions demonstrated that cathodoluminescence intensity from layers with small characteristic sizes of the porous entities (around 50 nm) is weaker than that inherent in bulk material, while porous layers with the pore diameter of around 500 nm exhibit much stronger luminescence.