Discovery generation of new laser dyes on the basis of quinolisinocoumarin's derivatives in a spectral range 490-580 nm. It is exhibited, that the greatest generative efficiency and photodurability the availability for given compoundes in the third standing coumarin's basis of the strong electron acceptor, for example carbamyl-, benzimidozoli- and benzthiazolyl-groups, and in a standing seven - electron donor N-(CH2) ₆ groups. Given quinolisinocoumarin's derivatives have high generative efficiency which exceeds known laser dyes in 2-3 times. Thus the photochemical stability exceeds rhodamine 6G on the order.

Dynamic behavior of the nonlinear Fabry-Perot interferometer with heavily doped n-GaAs internal layer under 20 ns laser pulses excitation has been studied. Optical bistability with less than 10 ns switch-OFF time has been demonstrated.

Nonlinear optical response of periodic structures based on ZnSe/ZnS heterostructures using interband excitation of a ZnSe sublattice by 1 50 fs laser pulses is reported. A considerable shift of reflection spectrum and large relative reflection changes were observed in a wide spectral range corresponding to the transparency region of ZnSe far from the intrinsic absorption onset. Evaluated refraction index change is about -0.02 with the relaxation time being about 3 picoseconds. The nonlinear refraction is supposed to be controlled by population induced absorption changes in ZnSe single crystals and relevant refraction index modification via Kramers-Kronig relations. The nonlinearity relaxation time is supposed to trace a transition from non-equilibrium to quasi-equilibrium distribution of electrons and holes within ZnSe conduction and valence bands, respectively, rather than electron-hole recombination time. The nonlinearity mechanism does not reduce to just population dependent absorption saturation but essentially results from the specific distribution function in the first instance after excitation.

We study the fluorescence intermittency of individual Dil-molecules on silicon dioxide surfaces with the focus on intermittency statistics on timescales above 15 milliseconds. On these time-scales intermittency statistics is no longer dominated by triplet blinking. We show that rather broad distributions of dark states must be present which give rise to power law distributions for on- and off-times. The off- time distribution depends on excitation intensity.

Scheelite-like disordered double sodium-lanthanum molybdate NaLa(MoO₄)₂ single crystals co-doped with Er³⁺ and different concentrations of Ce³⁺ have been grown by Czochralski technique. The 300K spectroscopic properties of the excited states ⁴S_3/2, ⁴I_11/2 and ⁴I_13/2 of Er³⁺ ions in grown crystals as a function of Cerium concentration have been investigated. The lifetime of ⁴I_11/2 have been found to reduce from 130 μs in the solely Er-doped sample to approximately 3.5 μs, when the concentration of Ce reaches 50 at. %. At the same time the lifetime of ⁴I_13/2 level at 300 K remains unchanged (3.7 ms) up to the concentration of Ce in crystal equal to 10 at. %, and reduces by less than 30% (2.6 ms) in the 50 at. % Ce co-doped sample. This result looks very promising from point of view of obtaining low-threshold 1.5 μm laser oscillation.

The optical properties of composite material made of metal nanospheres situated in the sites of three-dimensional lattice and embedded into dielectric matrix are considered. It is demonstrated that index of refraction of composite medium may acquire unit value at certain relations between dielectric constants. The method is developed for the description of optical properties of composite medium that takes into account retardation effects in nanospheres interactions. It is shown that obtained results coincide with Maxwell-Garnett theory in the limit of infinitesimal distances between nanospheres with respect to wavelength.

Influence of material anisotropy and gyrotropy on optical properties of fractal multilayer nanostructures is theoretically investigated. Gyrotropy is found to uniformly rotate the output polarization for bi-isotropic multilayers without any changes in transmission spectra. When introduced in a polarization splitter based on a birefringent fractal multilayer, isotropic gyrotropy is found to resonantly alter output polarizations without shifting of transmission peak frequencies. The design of frequency-selective absorptionless polarizers for polarization-sensitive integrated optics is outlined.

The new fiber components with the full photonic band gap by insert of opal matrixes in gap of a fiber line are proposed. The methods of opal matrixes doping by various chemical elements and compounds, and also formations of inverse opals, open a way to creation of various photon fiber elements with amplifying, nonlinear and/or sensors properties, and also opportunities of these properties management. Optical properties and some technological aspects of fiber photonic crystals formation are briefly considered.

The physical properties of pure GaSe and the crystals doped with 0.01÷3% Al, In, Te, and S have been observed comparatively to reveal the potentials for frequency conversion of laser emission. It has been shown that GaSe:S(greater than or equal to 3%) is the most promising material for practical applications.

Fluorescence and excitation spectrums of nanostructured thin Langmuir-Blodgett films with different numbers of monolayers deposited on nanoporous aluminium oxide have be investigated. Using the band calculations one showed that photo-induced reversible instability of electron orbitals for lattice holds in monolayers.

The distribution of 150 acentric borates over different crystal systems has been revealed. The rules for generation of boron-oxygen fundamental building blocks, three- and tetra-coordinated boron are specified.

Classification on symmetry and properties has been produced for >165 presently known noncentrosymmetric binary borate crystals. Comparative analysis of the compounds with using combination of the shortest oxide chemical bond lengths as a criterion reveals some principles for searching new optical borate materials promising for increased second order nonlinearity and creation of SFD mediums.

In this study the analysis of deformation and mode refractive index measurements of H:Ti:LiNbO₃ layers have been investigated. The variations of the lattice parameter in doped layer have been controlled by high-resolution X-ray diffraction measurements. It has been shown that the presence of Ti greatly impacts on crystal lattice deformation induced by subsequent doping by hydrogen. The stability of H:Ti:LiNbO₃ waveguides has been investigated by the high temperature phase freezing by quenching and relaxation to equilibrium phase at room temperature. The variation of the lattice parameter in H:Ti:LiNbO₃ layer appears to be smaller then that in H:LiNbO₃ layer formed at the same conditions.

Fullerene-doped dispersed nematic liquid crystal structures have been considered as new nanostructured materials with a high speed. The switch-on time of 50-100 μs has been obtained. The results are discussed from the viewpoint of an additional polarizability of the fullerene-doped systems and the possible quasi-transition from the nematic phase to the smectic one, which are caused by a complex formation between an organic molecule donor and a fullerene as electron acceptor. Self-organization in liquid crystal mesophase based on the new charge-transfer complexes has been revealed.

A new method of formation of radially and azimuthally polarized Bessel light beams has been proposed and experimentally realised. This method is based on interaction of radiation with layered periodic medium, including defect impurity - a layer of an uniaxial material. It has been shown that it is possible to control this process by changing the cone angle of the incident Bessel light beam.

Analogues of the dipyrromethene-BF₂ dye PM567 modified at the 8-position by methacryloyloxymethyl (P1MA), smethacryloyloxypentyl (P5MA), and p-methacryloyloxymethylphenyl (PAr1MA) groups have been copolymerized with methyl methacrylate (MMA), and these solid samples were studied by absorption, fluorescence, and photo-degradation spectroscopy. The absorption cross-section and stimulated emission cross-section spectra are determined. The fluorescence quantum distributions and fluorescence lifetimes are measured. High fluorescence quantum yields, Φ_F ≈ 0.9, have been obtained. The photo-degradation of the dyes is studied under cw laser excitation conditions. A high photo-stability was observed.

Photonic band-gap structures are of interest both from fundamental and practical points of view. They are known to enhance nonlinear, magnetooptical, electrooptical and other effects in the medium when frequency is near photonic band gap [1, 2]. Second harmonic generation is observed when phase-matching conditions are fulfilled, i.e. phase velocities of first and second harmonics are equal. Homogeneous media have their own material dispersion, so phase mismatch always presents. Anisotropy in some materials can compensate dispersion in specific directions, and such nonlinear crystals are commonly used in lasers and parametric light generators [3]. Photonic crystals are attractive for practical applications because of a large diversity of their dispersion properties comparing to homogeneous media. Varying photonic crystal parameters, such as lattice period, filling factor and refractive indices of media, one can manipulate its band structure.

Mie problem of scattering of an electromagnetic wave by a spherical particle with the modified boundary conditions which takes into account influence of a thin superficial layer is considered. Analytical expressions for partial amplitudes of scattered waves and excited inside the sphere, which usable at presence of anisotropy and girotropy of a superficial layer are found. Influence of thin dielectric layers on morphological resonances of Mie theory is numerically analyzed.

We report on anisotropic light scattering in nanoporous anodic alumina. Light coming at various angles with respect to the pore axis was found to be scattered predominantly in the solid angle adjacent to the pore axis. Such scattering indicatrix we explain in the terms of redistributed local density of photon states in irregular nanostructured materials. In the case of porous alumina local density of photon states and light scattering probability are increased in the direction of the pore axis. We demonstrate by the example of PAA that nanostructured aperiodic materials can possess birefringent properties. We demonstrate and explain formation of the scattering rings by transmitted laser light in birefringent nanoporous anodic alumina.

The near-field response of optically excited nanoparticle structure buried within thin dielectric layer is theoretically and numerically studied for the illumination and collection modes of a scanning near-field optical microscopy. As the probe we consider a single dipole-like particle that scans the surface of the sample. Nanostructure is modeled as a finite-size periodic array of dipole-like particles, the size of the structure is assumed to be much smaller than the wavelength of the external electromagnetic wave. The electromagnetic signal in a remote detector is proportional the time-average energy flux of the scattered probe field. For the determination of the field in the system the dyadic Green's function of the one layer system is used in the unretarded approximation. We have found that field distribution and the magnitude of the field intensity in the system strongly depend on the polarization of the exciting external waves and the inter-particle distances in the nanostructure. The near field distribution in the system under condition of local plasmon resonance, when the polarizability of every particle in the nanostructure was significantly increased, is also considered.

We suggest a new approach to the study of photonic crystals, based on direct visualisation of the photonic bandgap structure from Bragg diffraction patterns. Using high quality synthetic opals as photonic crystals, we have demonstrated how the Bragg diffraction of light can provide observation and analysis of the photonic band gap structure. We observed directly and photographed Bragg diffraction patterns as symmetrical sets of color spots on a screen, which appeared, displaced and disappeared, as the crystal was rotated relative to the incident laser beam. The diffraction patterns were observed under laser illumination with different wavelengths. The analysis of the experimental data can provide the number and orientation of the crystallographic planes responsible for the Bragg diffraction, as well as information about disorder in opal structure.

The results are presented of spectral calculations of extinction cross-section for scattering of E- and H-polarized electromagnetic waves by cylinders made of Veselago material. The insolvency of previously developed models of scattering is demonstrated. It is shown that correct description of scattering requires separate consideration of both electric and magnetic subsystems.

Changes in the spatial orientation of molecular components of a dicarbocyanine layer under the action of temperature and resonance laser excitation are studied experimentally. The rate and the limiting value of the orientation change increase with increasing radiation power density and temperature. The model adequately describing the experimental dependences is proposed.

The optical second harmonic response from small gold metallic particles with a diameter ranging between 20 and 100 nm is investigated with the technique of Hyper Rayleigh Scattering. The analysis is performed as a function of the polarization state of the incoming fundamental beam. For the particles with the smallest diameters, the nonlinear optical response is purely dipolar, arising from the surface of the particles owing to the breaking of the centrosymmetry of the particles. For larger diameter particles, the retardation effects cannot be neglected anymore, the response exhibiting a clear quadrupolar pattern. A general framework is proposed to discuss the experimental data, based on a a weighing parameter allowing the quanitfication of the relative magnitude of the dipolar and quadrupoloar contributions.

A theoretical approach for the calculation of the bimetallic nanoparticles absorption spectra has been developed as an extension of the Mie theory in which nanoparticle dielectric function is found by the weighted linear combination of the dielectric functions for particles made of the corresponding pure metals. We propose a simple method for the on-line monitoring of the bimetallic nanoparticles composition based on the measurement of the absorption peak position. Elaborated theoretical approach was used to investigate the polymer embedded Ag/Au nanoparticles. Calculated absorption spectra for the Ag/Au nanoscopic systems showed good agreement with the experimental data. Temporal evolution of the Ag/Au nanoparticles size and composition has also been investigated by this approach.

A simple high-speed photodetector of high-power laser radiation, based on the optical rectification effect in the nanographit film, is described. It operates without an external power source. The spectral dependence of the optical rectification effect in nanostructured carbon (nanographite) films obtained by plasmachemical deposition was studied in a wavelength range from 266 to 5000 nm. The performance of this device was demonstrated by detecting pulsed laser radiation using the second, third, and fourth harmonics of radiation from an YAG:Nd³⁺-laser with passive Q-switching, radiation from light oscillators based on stimulated Raman scattering in compressed hydrogen and parametric oscillator pumped by the second harmonic of the YAG:Nd³⁺-laser. It was shown that the photodetector response time is shorter than 0.5 ns. It is suggested that nanographite films are promising materials for detectors of ultrashort laser pulses in the IR, visible, and UV spectral intervals and for generators of electromagnetic radiation operating in the terahertz frequency range.