This PDF file contains the front matter associated with SPIE Proceedings Volume 6613, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

Phase-locked lasing of a three-channel holographic laser system based on self-pumped phase-conjugate loop oscillators is experimentally demonstrated in accordance with a transient numerical modeling. The Nd:YAG laser system had three laser outputs as the self-Q-switched laser monopulses interfering with a fringe pattern visibility tending to unity.

A new method of forming nondiffracting and nondispersing azimuthally (or radially) polarized pulsed Bessel beams is suggested. These light fields are promising for photolithography, confocal microscopy, and optical communications. The method is based on the splitting of a supershort arbitrarily polarized Bessel pulse, which propagates in a one-dimentional photonic crystal, into two pulses having the mutually orthogonal polarizations.

The diffractive optical element as intracavity gradient mirror ofYAG:Nd laser has been offered. The peculiarity of this element is using of zero order diffraction. The damage threshold of this mirror is 5-10 J/cm². There's been noticed that during the work with full aperture of active element divergence of one-mode radiation of laser with gradient mirror became 1,5x10^-4 rad with 30 mJ energy.

It is investigated the effect of a finite cross-relaxation rate on the transverse radiation dynamics of a wide-aperture laser. The spatiotemporal structure of the optical field in wide-aperture laser with different cavity geometry and the finite mirrors is obtained. The conditions are found for the emergence of periodic autowaves for positive and negative frequency detuning. These conditions are shown to depend strongly on the cross-relaxation rate.

Powerful laser systems of new generation are created nowadays - National Ignition Facility (NIF, USA), Laser Megajoule (LMJ, France) and ISKRA-6 (Russia). The most important problem after power characterization is formation of radiation of the necessary quality. For this purpose the use of adaptive optical systems (AOS) is provided in all three facilities. The present work is mainly devoted to characteristics definition and working off of the most problem AOS elements - wavefront sensor and wide-aperture deformable mirror for "ISKRA-6".

The two-channel optical circuit for measurement and the control of divergence of laser radiation over the sizes of the prints received in a plane of registration is considered. Analytical expressions for estimation of single and a solid angles and also for definition of divergence sign are presented. Experimental results are submitted. A few advantages are compared with the known circuit of a focal spot.

A novel method for measuring the intensity profile of far-infrared radiation is presented. The idea is to measure nonstationary thermally induced variations in optical thickness of a target heated by the studied radiation. The optical thickness variations are observed by an interferometer. Beams with an aperture up to 60 mm may be measured with a spatial resolution of I mm.

The optical system containing polarizer, analyzer and two crystalline plates, which are cut parallel to the optic axis is considered. The transmission spectrums of two planar - cross crystalline plates made from niobate of lithium crystal are calculated. The possibility of controlling the spectrum at different combinations of plates' orientation relatively to the polarizer's transmission plate and also at rotation of the analyzer is shown.

The experimental investigations of photo-induced quenching of singlet oxygen luminescence in fullerene solutions (C₆₀ and C₇₀ in CCI₄) at optical pumping have shown presence of dependence of ¹g&Dgr;g 0₂ lifetime in a solution on initial fullerene concentration, optical pumping intensity and temperature of the solution. The increase of any of these three factors results in the reduction of the singlet oxygen lifetime in the solution, and for C₇₀ these effects are much stronger than for C₆₀. It is shown that at pulse optical excitation the solution C₆₀ is stable and restores the properties some time after the influence. These effects can not be explained by only thermal mechanism, the major part is played by process of formation of fullerene-oxygen complexes which as a quencher for the state ¹Δg 0₂. These complexes are unstable and are decomposed later into initial components. The initial fullerene C₆₀ concentration is completely restored in the solution. The initial fullerene C₇₀ concentration is partly restored in the solution. All these conclusions are based on the results of the study of absorption spectra of fullerene solutions before and some time after the influence on solutions of pulse optical excitation. For CW irradiation, the effects of photoinduced quenching of singlet oxygen luminescence in fullerene solutions have been studied as well. These phenomena are to be considered when developing a generators of singlet oxygen for fullerene-oxygen-iodine laser. The temperature of solution also plays an important role in the development of singlet oxygen generators. To increase the generator efficiency it is necessary to cool the solution efficiently.

Spectral and some nonlinear optical properties of multicomponent solutions, which contain fullerene C₆₀, perylene, and tetramethylbenzidine, are investigated. In such systems, enhanced optical limiting and all-optical switching are due to a formation of radical ions by a photoinduced electron transfer. A diagram of electronic states is thermodynamically calculated and prove for efficiency of the photoinduced electron transfer via the excited singlet state of C₆₀ is shown.

Singlet oxygen generation by fullerene and astralen containing surfaces and powders under visible irradiation was studied in water and organic liquids by means of ¹Δ_g state luminescence and chemical scavenger transmittance measurements. The chemical method, pioneered for solid photosensitizers of ¹0₂, allowed to measure the singlet oxygen concentration in the aqueous medium down to 10⁸ cm^-3. The singlet oxygen sensitizing by the solid-phase fullerene-containing systems was found to be 100 times less effective then by fullerene in solution. The results obtained confirm the applicability of these structures in biology and medicine.

The results of study of sorption properties of fullerene and fullerene-like nanostructures with respect to molecular oxygen, nitrogen and helium are given. The influence of experimental conditions (time, gas pressure, temperature and structure of sample) on these properties is investigated. At an irradiation of fullerenes and others fullerene-like adsorbents by light of a laser or a pulse lamp an output in a gas phase of oxygen, adsorbed by these samples, was observed. At interaction photoexited fullerene and adsorbed oxygen there is a transfer of excitation to oxygen and the essential part of oxygen in a gas phase was in the exited singlet states. These effects are confirmed by experimental observation of luminescence pulses on the wavelengths 0.762 and 1.268 microns with specific pulse duration. The processes of formation and quenching of singlet oxygen at pulse photoexcitation and photodesorption are considered. The fullerene and fullerene-like coatings on glass, ceramic, and porous metal surfaces were investigated. Spectral and temporary distributions of singlet oxygen luminescence for various adsorbents surfaces were studied. The influence of adsorbents surfaces cooling of on singlet oxygen amount obtained in a gas phase and on luminescence intensity has been investigated. On the base of investigations of physical principles of the singlet oxygen generation during interaction of the oxygen molecules with the solid-state photoexcited fullerenes and carbon nanostructures was proposed and realized the prototype of the singlet oxygen generator for the fullerene-oxygen-iodine laser, working in the pulsed mode.

The correlation properties of fractal speckle distributions arising from superposition of three speckle waves propagating perpendicularly to one another are studied theoretically. The analytical expressions are derived for the intensity correlation of the superposed speckle fields, and the theoretical results are verified by means of computer simulations. It is shown that the spatial anisotropy of speckle patterns exists even when the three speckle waves are interfered with one another. This spatial anisotropy affects the power law distribution of intensity correlations for fractal speckles, leading to the speckle pattern which is not self-similar in two or three dimensions. As an application of the superposed speckle field, a method to fabricate a disordered medium by illuminating photopolymer with multiple laser speckle waves is proposed. Some preliminary experimental results are shown.

The photorefractive properties of the lithium niobate crystals depend strongly on the kind of the doping admixture. The study of the photorefractive light scattering (PRLS) in the LiNbO₃ crystals with various doping admixtures allows to gain informaton of the processes taking place in the crystals. This problem is solved using models describing the experimental results. This paper presents new experimental results of nonselective and selective PRLS investigation in the LiNbO₃:Rh crystal and proposes also a model within the framework of which the experiment data are explained.

Novel nonlinear optical effect - stimulated globular scattering (SOS) - was discovered. SGS was observed both in forward and backward direction. Pure opal crystal consisting of the close-packed Si0₂ globes with diameter 200 nm, and crystal with pores filled with molecular liquid have been studied. Two Stokes components, shifted from the exciting light frequency by 0.4 - 0.6 cm^-1 have been observed.

Is shown, that the field of a wave by a scattered rough surface, has the spatial distribution similar to a field of a diffraction wave on an aperture, conterminous under the form and the size with illuminated area. A maximal intensity in diffractive orders form speckle pattern. Dependence of a time spectrum of intensity fluctuations, of scattered radiation by a moving surface from size of a roughness is received. With use of dynamic speckles experimental measurement of base lengths and a root-mean-square roughness on these lengths is lead. Results of experiment have confirmed the offered model of a scattering and have shown an opportunity of simultaneous definition of ensembles of statistical parameters of a roughness.

In this paper self-consistent microscopic theory of nonlinear-optical response in ultrathin (≈1 nm) metal films has been developed. The single-electron wave functions, charge and current densities and field distribution in and out of film has analytically calculated in second approximation of perturbation theory. Electron wave functions calculated using density functional theory in time-dependent local density approximation. For ions a jellium model was used. Constructed theory describes second harmonic generation (SHG) from both of quantum well transitions and collective electron excitations.

The light-induced forces in the aggregates of metal nanoparticles are studied with the Newton's and coupled dipole equations. The simulations imply a linear intrinsic optical response of the particles and host medium. Large and relatively fast third-order optical nonlinearity of such a nanocomposite is shown to originate from the light-induced motion of the particles. The nonlinear absorption coefficients of an artificial medium composed of 5-particles aggregates are simulated at different intensities and frequencies of the incident light. The calculated nonlinear absorption appears to be of the same order of magnitude as typically measured for the silver colloids.

Absorption of light by nanoparticle in the presence of resonant atom is theoretically investigated. Both the direct absorption of light by the nanoparticle and the absorption due to cascade energy transfer from light to the atom and then to the nanoparticle are taken into account. It is shown, that the cascade energy transfer is proportional to the imaginary part of the Green's photon function in this conditions. The Green's function is calculated in the quasi static approximation because of smallness both the size of the nanoparticle and the distance between it and the atom. The resonant atom is described in the generalized two-level model taking into account the direction of the atomic dipole moment. It is shown, that the light absorption by the nanoparticle can be increased by several orders because of presence of the atom. In the case when the nanoparticle is surrounded by collection of atoms it is found that the optical bistability is possible in this system. The range of parameters leading to the bistable behavior is found.

CdSe/ZnS quantum dots in solution ad in condensed phase have been investigated by methods of laser induced luminescence. Anti-stokes photoluminescence (APL) of CdSe/ZnS nanoparticles in the solutions and in the films has been studied under action of laser radiation of various wavelengths. The dependencies of APL of CdSe/ZnS nanoparticles ensembles on exciting radiation intensity, temperature and quantum dots concentration have been studied. It is shown that the mechanism of APL formation in CdSe/ZnS nanoparticles is thermal.

Optical properties of the films with high concentration of semiconductor core-shell CdSe/ZnS nanocrystals under action of visible laser radiation in a wide range of power densities have been investigated. It's shown that in the films with ultimate concentration ofthe nanocrystals a quantum-size effect is observed. High concentration of the nanocrystals in the films and the presence of dipoles caused by nanoparticles asymmetry lead to strong shift of quantum-size peaks in absorption and luminescence spectra compared to the solution and the films with low concentration of the nanoparticles. The altitude of the shift depends on the thickness of the films and varies from 35 nm to 50 nm. The luminescence spectra of the films don't change until the power density of exciting laser radiation exceeds 1x10⁶ W/cm². The regimes of laser action on the films of the nanoparticles with power densities beyond the threshold of films destruction (from 5x10⁶ W/cm² to 1x10⁹ W/cm²) have been investigated.

An influence of pulsed laser radiation on the properties of monolayer of copper-based planar nanostructures has been investigated. Novel data are obtained on optical and physico-chemical characteristics of the nanostructures. Plasmon resonances shift, spectral properties and luminescent intensity of films are explained by the effects of metal particles oxidation and aggregation. The laser induced changes of physico-chemical characteristics were obtained from optical and AFM measurements. It has been shown that effect of nanostructure transformations depends on intensity of pulse laser, metal particles concentration and initial level of particles oxidation.

We reveal conditions of collective photoinduced luminescence occurrence in model solutions. Experimental study of transmission and luminescence of concentrated Rhodamine 101 solutions at excitation by laser pulses in the Stokes and anti-Stokes spectral area showed that the collective photoinduced luminescence, competing with stimulated emission, plays a significant role in luminescence formation at high pumping energies. Cooling and heating of the solutions are estimated. Cooling photodynamics is analyzed for solutions of complex molecules at pulsed, both Stokes and anti- Stokes, excitation of admixture centers. It is shown, that in anti-Stokes area the competition of the compelled processes of absorption, two- photon absorption, light suppression and the photoinduced collective cold light result to occurrence of area in which there is a change of a sign on temperature processes.

Laser-induced formation of polymer Bragg grating filters for Dense Wavelength Division Multiplexing (DWDM) applications is discussed. Acrylate monomers halogenated with both fluorine and chlorine, which possess absorption losses less than 0.25 dB/cm and wide choice of refractive indices (from 1.3 to 1.5) in the 1.5 &mgr;m telecom wavelength region were used. The monomers are highly intermixable thus permitting to adjust the refractive index of the composition within ±0.0001. Moreover they are photocurable under UV exposure and exhibit high contrast in polymerization. These properties make halogenated acrylates very promising for fabricating polymeric waveguides and photonic circuits. Single-mode polymer waveguides were fabricated on silicon wafers using resistless contact lithography. Submicron index gratings have been written in polymer waveguides using holographic exposure with He-Cd laser beam (325 nm) through a phase mask. Both uniform and apodized gratings have been fabricated. The gratings are stable and are not erased by uniform UV exposure. The waveguide gratings possess narrowband reflection spectra in the 1.5 μm wavelength region of 0.4 nm width, nearly rectangular shape of the stopband and reflectivity R > 99%. The fabricated Bragg grating filters can be used for multiplexing/demultiplexing optical signals in high-speed DWDM optical fiber networks.

Universal method has been proposed for calculation of polyhedra space formation of each cation in the crystal lattice. Generation of simple, chain, layer and frame formations has been predicted and verified for non-centrosymmetric oxide crystals widely used in nonlinear optics.