Table of contents

The reflection spectra of Gd₂O₃ and Gd₂O₃:Er nanoparticles have been investigated. Several types of absorption centers associated with Er³⁺ activator ions and intrinsic lattice defects have been revealed. It was found that interband absorption is formed by indirect optical transitions with participation of phonons. The values of energy gap and phonons energy were determined.

Hybrid halide perovskites have emerged as one of the most promising type of materials for thin-film photovoltaic and light-emitting devices. Further boosting their performance is critically important for commercialization. Here we use femtosecond laser for post-processing of organo-metalic perovskite (MAPbI₃) films. The high throughput laser approaches include both ablative silicon nanoparticles integration and laser-induced annealing. By using these techniques, we achieve strong enhancement of photoluminescence as well as useful light absorption. As a result, we observed experimentally 10-fold enhancement of absorbance in a perovskite layer with the silicon nanoparticles. Direct laser annealing allows for increasing of photoluminescence over 130%, and increase absorbance over 300% in near-IR range. We believe that the developed approaches pave the way to novel scalable and highly effective designs of perovskite based devices.

Thin films of Se/Bi heterostructure were obtained by the by thermal vaporization of Se and Bi powders in a vacuum camera. A focused He-Ne laser beam at 632.8 nm is shown to cause local darkening of Se/Bi heterostructure at incident power densities above 3.5 kW/cm². The possibility of laser recording of diffraction grating by this technique is demonstrated. It is shown that the resistance between the electrical contacts on the heterostructure reduces as the lines between these contacts are recorded. Data obtained from Raman spectra before and after laser treatment indicate that the darkening is accompanied by Bi₂Se₃ formation.

In this work, a narrow band pass Fabry-Perot filter is designed which can be used in an airborne light detection (ALB) and ranging bathymetry. LIDAR is done by reflecting a pulse laser beam from a target and detecting the round-trip propagation time between the source and the target. ALB systems consist of Nd: YAG laser that emits the pulses at two different wavelengths such as 1064 nm and 532 nm. Infrared pulses at 1064 nm are reflected from the water surface and the green pulses at 532 nm which penetrates the water surface and are reflected from the ground. Filters are desirable to suppress the ambient light that is reflected by the surface of the water or an atmosphere which always enter the detector as a noise. The designed filter shows a high quality with an average transmission of more than 95 % at 532 nm which is considered as practically ideal for water penetration in typical coastal waters.

We consider theoretically recently proposed a new possibility of creation, erasing and ultrafast control of population density grating. Such grating can be created in resonant medium when ultrashort pulses with duration smaller than relaxation times in the resonant medium (coherent light matter interactions) propagate without overlapping in this medium. Possible applications in the ultrafast optics such as optical switcher and laser beam deflector are discussed.

A comparison of the Casimir force theory and experiments with Si rectangular gratings is performed. We use Rayleigh decompositions to evaluate the Casimir force in Si grating – Au sphere systems for two Si grating samples. Ratios of exact Casimir force to proximity force approximation (PFA) and pairwise additive approximation (PAA) results for the Casimir force are found. The difference in the use of theoretical PFA results and PAA results extracted from experimental data is emphasized.

Sunlight is the primary source of light in the buildings and automobiles. However, infrared (IR) radiations in the sunlight result in heat generation. In this work, dielectric-metal-dielectric (D-M-D) heat reflectors are demonstrated which is transparent for visible light 400-700 nm while reflecting IR radiations above 700 nm. These reflectors are based on a TiO₂-Ag-TiO₂ sandwich structure with 22 nm of the thickness of each layer shows the maximum transmission of 83 % theoretically and 81 % experimentally in the visible wavelengths region observed by ellipsometer; a maximum reflection of IR wavelengths was also observed. The study was also extended to experimental verification of heat transmission by testing these reflectors both under IR lamp and sun in the month of June 2016. Experimental results confirm less heat transfer through these filters as compared to the commercially available tinting paper. As a practical application, these reflectors can be used in automobiles and houses during summer to reflect back the excessive heat from the sun.

Quantum random number generator (QRNG) allows obtaining true random bit sequences. In QRNG based on quantum nature of vacuum, optical beam splitter with two inputs and two outputs is normally used. We compare mathematical descriptions of spatial beam splitter and fiber Y-splitter in the quantum model for QRNG, based on homodyne detection. These descriptions were identical, that allows to use fiber Y-splitters in practical QRNG schemes, simplifying the setup. Also we receive relations between the input radiation and the resulting differential current in homodyne detector. We experimentally demonstrate possibility of true random bits generation by using QRNG based on homodyne detection with Y-splitter.

It is shown experimentally that laser action on silver-containing photosensitive glasses can be used for optical information recording in octal code. The change of irradiation dose results in the change of luminescence or absorption intensity in irradiated zones.

We describe the generation of photon pairs entangled in optical angular momentum (OAM) through spontaneous four-wave mixing (SFWM) in circular arrays of nonlinear waveguides. We show that the incorporation of the array twist along the waveguides can enable robust generation even in presence of defects and inhomogeneities. We present analytical results and numerical simulations based on coupled-mode equations for the classical pump field and a discrete Shrodinger equation for the biphoton wave function.

In this paper we investigated the entanglement dynamics between two superconducting qubits interacting with two microwave modes of independent coplanar cavities taking into account the direct dipole-dipole interaction. The model with different qubit-field couplings and detunings is under consideration. Using the dressed-states representation technique we derived the exact solution for considered model with qubits prepared initially in entangled states and vacuum field modes. We have carried out the dependence of the atom-atom entanglement on the strength of the dipole-dipole interaction and other parameters of the considered system such as different coupling constants and detunings. The results showed that the presence of a sufficiently large dipole-dipole interaction leads to stabilization of entanglement.

We probe the resonance properties of complex plasmonic structures by Scanning Near-field Optical Microscopy (SNOM). Groups of three differently arranged silver nanoparticles covered with Surface-Enhanced Raman Scattering (SERS) analyte Rhodamine 6G were chosen to visualize electric field distribution nearby the nanostructures. The particles were grown on the surface of a silver-ion-exchanged glass using thermal poling and annealing of the processed glass substrate in hydrogen atmosphere. The morphology of the nanoparticles and their arrangement in the groups were characterized with Atomic Force Microscopy (AFM). The near-field SERS maps superimposed on the AFM scans of the studied groups of nanoparticles visualize the Raman hotspots with 100 nm resolution.

We have studied the influence of a spacer in a multihelicoidal Bragg fiber with a twist defect on the emerging of localized topological states. We have shown that if such a fiber is excited with a Gaussian beam this leads to the appearance of a defect-localized mode, whose topological charge coincides with the order of rotational symmetry of the fiber's refractive index distribution. The influence of the spacer on this mode is studied.

Article deals with security criterion for sub-carrier wave quantum key distribution (SCW QKD) protocol in errorless channel. SCW QKD is promising type of QKD system in a field of telecommunications due to its compatibility and very efficient using of channel spectral bandwidth. Corresponding expression of security condition was derived for the first time in this work.

Micron, submicron, surface-periodic and nanostructures were obtained by laser ablation in a liquid method on the titanium plate surface and the nickel foil surface. Electrochemical deposition of the nickel in the modified region of the titanium leads to the formation of conical structures 6 μm in height and filamentary nanostructures on the separated film. During deposition on the laser-modified nickel target, the separable film retains the period of the structures from which it is removed. The component titanium target coated with a nickel film was also irradiated. After separation of the nickel film, perforations with an average diameter of 1 μm and holes up to 50 μm in diameter were detected.

Quantum imaging with undetected photons is recently appeared promising brunch of quantum optics. Due to properties of photon pairs (signal and idler), generated via spontaneous down-conversion (SPDC) process and phenomenon of induced coherence, one can obtain phase or intensity image of object without detecting of the photon, interacting with it. The theoretical treatment and limitations of such a system with an only crystal and increased brightness are given.

By using the laser printing technique, for the first time we fabricate spherical nanoparticles of germanium-antimony-telluride alloy possessing a high refractive index and amorphous-to-crystalline phase transition. The nanoparticles are examined by means of optical dark field micro-spectroscopy, which shows scatterers with different colours (with different optical resonances). The direct measurements of their diameters by using the transmission electron microscopy reveal that the nanoparticles' colours are related to different sizes of the nanoparticles. While most of nanoparticles are homogeneous, our study shows that some fabricated particles have a core-shell structure.

Near-surface color centers in sodium fluoride nanocrystals have been formed. At pre-irradiation annealing of sodium and lithium fluorides samples at temperatures of 623 K and above, the near-surface color centers in them have not been found after γ-irradiation. Annealing lithium fluoride nanocrystals with the near-surface defects leads to their transformation into bulk ones of the same composition.

Results of indium phosphide structures research, showing the possibility of using in the near infrared range (NIR) photocathodes of InP / InGaAs, are represented. An optimal method of obtaining the atomically clean indium phosphide surface was suggested. The spectral characteristics of indium phosphide and InP/InGaAs heterostructure were given. Researches of the photoemission dependence of the structure with surface grid electrode upon different supply voltages were carried out.

On the basis of quantum stochastic trajectories approach it is shown that a single atom laser with coherent pumping can generate not only coherent states, but squeezed and Fock states, when different schemes of detection are followed by coherent feedback pulses or feedforward actions.

The application of optoelectronic techniques to the generation and detection of THz radiation is now well established. Wide gap semiconductor crystals of groups II-VI, III-V and III-VI are abundantly used. However, some limitations are occurred while using powerful laser systems. In this paper we introduce experimental results of two-photon absorption (2PA) in ZnSe, ZnTe and GaP studied with femtosecond pump-probe supercontinuum spectroscopy. Using of supercontinuum helps us to measure 2PA absorption dynamics and nonlinear index of refraction in wide frequency ranges. Besides influence of Fe concentration in ZnSe:Fe crystals on transmitted THz radiation is described.

We report on theoretical studies of short optical pulse propagation through resonant photonic crystals (RPCs) based on conventional II-VI quantum wells (QWs) and van-der-Waals (vdW) Bragg heterostructures composed of extreme-2D monolayers. The parameters needed for modelling were determined by fitting of the experimental reflectance spectra. The delay of the transmitted picosecond optical pulses is predicted to be larger in vdW structures than in the structures with QWs due to the higher radiative width of the exciton resonance. Moreover, in the vdW RPCs, the pulse shape undergoes smaller modification owing to the almost linear dispersion of the "slow" mode. High-quality extreme-2D monolayers will allow for even stronger delays without distortion and small intensity decrease, needed for nanophotonics applications.

We report on micro-photoluminescence studies of InAs/AlGaAs single self-assembled quantum dots grown by molecular beam epitaxy. A variation of the exciton fine structure splitting induced by the anisotropic part of the electron-hole exchange interaction is systematically studied depending on the exciton emission energy and the insertion of a GaAs interlayer prior formation of the InAs QDs.

We report on synthesis, structure, Raman and optical spectroscopy of transparent glass-ceramics (GCs) containing nanocrystals of rare-earth orthoniobates, Yb³⁺,Ho³⁺:YNbO₄ and β-quartz solid solution. Under the near-IR excitation, the GCs exhibit intense upconversion luminescence which color properties can be tuned by the heat-treatment regime due to the structural changes in the orthoniobate nanocrystals. The developed GCs are promising as thermal shock resistant green phosphors.

Photoreflectance (PR) spectra of Al_xIn_1-xSb-based heterostructures have been obtained by using a novel photomodulation Fourier-transform infrared (FTIR) spectroscopy method. The studied samples - bulk Al_xIn_1-xSb epilayers and InSb/Al_xIn_1-xSb heterostructures - were grown by molecular beam epitaxy on semi-insulating GaAs substrates via AlSb buffer layers. The critical-point energies E₀ and E₀+Δ₀ of Al_xIn_1-xSb alloys of various direct-gap compositions were defined from the PR spectra features. It was found that the E₀ values are greater than the observed Al_xIn_1-xSb photoluminescence peak energy, with the difference increasing with x. For the InSb/Al_xIn_1-xSb heterostructures, PR signals corresponding to Franz-Keldysh oscillations in the alloy barrier have been observed. Analysis of their period has allowed one to determine the intensity of the internal electric field in Al_xIn_1-xSb layers. This result enables evaluation of the surface Fermi level pinning, and elucidation of the effect of doping in such heterostructures.

In the course of studies have been conducted a method of forming the phase diffractive optical elements (DOEs) by direct laser writing in thin films of aluminum. The quality of the aluminum films were investigated depending on the parameters of magnetron sputtering process. Moreover, the parameters of the laser writing process in thin films of aluminum were optimized. The structure of phase diffractive optical elements was obtained by the proposed method.

We have experimentally studied the photoluminescence from InGaAsSb/AlGaAsSb quantum wells of different width under different levels of interband optical pumping. The dependences of photoluminescence intensity at spectral maxima on carrier concentration were theoretically calculated. This dependence was received using the rate equation taking into account the role of radiative and nonradiative recombination. Comparison of the theoretical and experimental results allowed to determine the nonequilibrium carrier concentration in quantum wells at certain experimental conditions.

The generation of the ring mode-locked laser containing resonant absorption medium in the cavity was investigated. It is shown that near the strong resonant absorption lines a condensation of polaritons arises. Intensive radiation looks like as superradiance in a medium without population inversion. We studied theoretically the microscopic mechanism of these phenomena. It was shown that in this system in absorbing medium a strong self-induced difference combination parametric resonance exists. Superradiance on polaritonic modes in the absorbing medium are due to the emergence of light-induced resonant polarization as a result of fast periodic nonadiabatic quantum jumps in the absorber.

Two-photon absorption cross sections of Coumarins 102, 153, 307 solutions in methanol in the wavelength range of 730-870 nm were measured. The maximum cross section for two-photon absorption in this wavelength range were 26±7, 36±9, 28±7 GM for Coumarins 102, 153, 307, respectively. The absolute value of the cross sections was determined by comparison with a fluorescein (43 GM at a wavelength of 790 nm). The dependence of the two-photon absorption cross section on the excitation wavelength coincides with the shape of the single-photon absorption cross section.

The fabrication of the periodic structures, that is two-dimensional photonic crystals (2D PhCs) based on Si-materials by electron beam lithography (EBL) technique has been studied. We have investigated basic lithography processes such as designing, exposition, development, etching and others. The developed top-down approach allows close-packed arrays of elements and holes to be formed in nanometre range. This can be used to produce 2D PhCs with emitting micro-cavities (missing holes) with lateral size parameters with an accuracy of about 2% in the Si (100) substrate and in silicon-on-insulator structures. Such accuracy is expected to be sufficient for obtaining the cavities-coupling radiation interference from large areas of 2D PhCs.

Nanotubular layer of zirconia with an thickness of 10 ± 1 μm and an outer/inner diameters of nanotubes of 80/60 ± 5 nm was synthesized by anodization in the electrolyte based on ethylene glycol with small amount of water and ammonia fluoride. It is shown that the obtained samples before and after annealing in air at 400 °C consist of 90 % and 79 % tetragonal, 10 % and 21 % monoclinic phases, respectively. Analysis of diffuse reflectance spectra showed that the thermal treatment leads to a decrease in concentration of surface Zr³⁺-centers. Under the assumption of direct allowed transitions, the bandgap width was estimated to be E_g = 5.41 ± 0.01 eV and 5.66 ± 0.01 eV for as-grown and annealed samples, respectively.

With use of the travelling-wave geometry approach, integrated superconductor-nanophotonic devices based on silicon nitride nanophotonic waveguide with a superconducting NbN-nanowire suited on top of the waveguide were fabricated. NbN-nanowire was operated as a single-photon counting detector with up to 92 % on-chip detection efficiency in the coherent mode, serving as a highly sensitive IR heterodyne mixer with spectral resolution (f/df) greater than 10⁶ in C-band at 1550 nm wavelength.

We report on micro-photoluminescence studies of individual self-organized CdTe/ZnTe quantum dots intended for single-photon-source applications in a visible spectral range. The quantum dots surface density below 10¹⁰ per cm² was achieved by using a thermally activated regime of molecular beam epitaxy that allowed fabrication of etched mesa-structures containing only a few emitting quantum dots. The single photon emission with the autocorrelation function g⁽²⁾(0)<0.2 was detected and identified as recombination of charged excitons in the individual quantum dot.

Nowadays the best single photon detectors from a practical view are those based on InGaAs/InP avalanche photodiodes, operating at a wavelength of 1.55 μm. In this work the characteristics of such a detector of our development are studied, while operating in Geiger mode with a synchronization frequency of 312.5 MHz. The dependence of quantum efficiency and noise levels on the active area are studied.

We investigate Laguerre-Gaussian vortex laser beam injection into an optical fiber. Modelling of radiation entering an optical fiber with plane (cylinder) and axicon (cone with diffrent apex angle) micro-relief is numerically investigated by the finite difference time domain (FDTD) method.

The plasmonic absorption spectrum of THz radiation in the graphene with periodic metal grating is theoretically studied. It is shown that graphene exhibits strong plasmon absorption resonances at the frequencies of plasma oscillations in graphene for narrow-slit metal grating and a thin barrier layer.

We report on development of superconducting single-photon detectors (SSPD) with high intrinsic quantum efficiency in the wavelength range 1.31 – 3.3 μm. By optimization of the NbN film thickness and its compound, we managed to improve detection efficiency of the detectors in the range up to 3.3 μm. Optimized devices showed intrinsic quantum efficiencies as high as 10% at mid-IR range.

We investigate surface plasmon-phonon polaritons in n-doped GaAs with the aim to obtain terahertz radiation emission. Dispersion of the surface plasmon-phonon polaritons is theoretically simulated taking into account contributions of the lattice and electron subsystems to the dielectric permittivity of n-GaAs. It is shown that regular grating at outer surface of GaAs provides a possibility to convert surface plasmon-phonon polaritons into terahertz photons and vice versa.

Metal corrosion protection is the main problem of all metal structures. Estimated to NASA, the loss of metal around the world is about of 2.5 trillion dollars, equivalent to 3.4% of global GDP. In our work we used a CW fiber laser with the wavelength of 1064 nm and a power up to 18, 4 W for laser irradiation of metal surfaces. We report on the optimal treatment of the metal corrosion with laser power density in the range from 7*10⁴ to 9*10⁴ W/cm². After the process of laser treatment of steel surface we observe decreased roughness of steel and a small change in its chemical composition.

We have performed a numerical study of whispering gallery modes of ring and race-track optical microresonators. Mode excitation was considered and their spectra and electromagnetic field distributions were calculated via numerical solution of the Helmholtz equation. We pay additional attention to features of eigenmodes in race-tracks in contrast with ring resonators. Particularly, we demonstrate that modes in race-tracks are not "classic" WGM in terms of total internal reflection from a single boundary, and an inner boundary is essential for their formation. The dependence of effective refractive index of race-tracks modes on the resonator width is shown.

CsPbX₃ (X = Cl, Br, I) quantum dots were synthesized using hot-injection method at various temperatures (50–200°C), resulting in quantum dots size change and corresponding photoluminescence shift. During anion exchange, continuous formation of intermediate solid solutions was observed resulting in fine adjustment of photoluminescence peak position. Dynamics of photoluminescence spectra under continuous laser irradiation for anion exchange was studied. It is necessary for anion exchange that halide should be in ionic, not molecular, form.

We modeled and fabricated integrated optical Bragg waveguides on a silicon nitride (Si₃N₄) platform. These waveguides would serve as efficient notch-filters with the desired characteristics. Transmission spectra of the fabricated integrated notch filters have been measured and attenuation at the desired wavelength of 1550 nm down to -43 dB was observed. Performance of the filters has been studied depending on different parameters, such as pitch, filling factor, and height of teeth of the Bragg grating.

Multilayer photonic crystal structures with bleaching layers are being investigated. In order to calculate the characteristics of ultra-wideband filters on their basis, T-lines lossless model was used. Amplitude-frequency characteristics for the synthesized filters of 5th, 11th and 17th orders are given. It is proved that by a significant increase in filter N order, the difference between the connection coefficients of central resonators' layers' becomes negligible. This makes it possible to develop 27-order filter, in which almost half of the layers are realized by periodic interchange of only two identical high-contrast materials. The investigated band-pass filters, including the ones on a glass substrate, have high frequency-selective properties at a relative bandwidth of 80%.

Hybrid composites of CdS-core ZnS-shell nanoparticles embedded in polyvinylpyrrolidone (PVP) matrixes have been prepared and characterized. Cadmium sulfide (CdS) nanocrystals were grown in water-propanol-2 solutions containing high-molecular (Ms=1300000) polyvinylpyrrolidone (PVP) at room temperature using cadmium nitrate and sodium sulfide as the cadmium and sulfur sources, respectively. The CdS/ZnS-PVP suspensions have promising optical properties for nanocomposite films based on. Nonlinear optical properties of diluted CdS/ZnS sols were studied at 532 nm and 5 ns laser pulses by using the Z-scan technique. Dependence of the nonlinear-optical coefficients on the CdS weight has been obtained.

Rectification of terahertz radiation in a spatially periodic graphene structure with dual grating gate is theoretically studied. The calculated current responsivity is an order of magnitude greater than the responsivity of conventional plasmonic detector based on the field-effect-transistor array.

Additively colored fluorite crystals are of considerable interest as a holographic recording medium. Due to very high stability as well as potentially large refractive index modulation, its possible to use holograms recorded in these crystals as high quality diffractive elements and photonic-crystalline structures. Therefore, it is important to be able to correctly and accurately analyze such structures. Spectral dependencies of absorption coefficient and refractive index profiles are the most precious characteristics in this regard. Unfortunately, they are also the most elusive ones. In this study the required parameters were obtained by a method based on the analysis of selectivity hypercontours (combined spectral and angular dependencies of diffraction efficiency) using the Kogelnik's coupled wave theory in wide optical spectral range. Hologram profile was reconstructed from first three spatial harmonics. The results were crosschecked with monochromatic analysis to prove the validity of proposed technique.

In this work we review principles and applications of a method of phase shifting profilometry with using of optical vortices imbedded into the probe beam. High spatial resolution caused by vortex phase sensitivity is analysable to retrieve the 2D and 3D shape of optically transparent and reflecting surfaces with exceeding of optical diffraction limit. This method applicable for non-destructive testing of thin films, live cells and biological tissues in real-time regime. Automatic processing of vortex interferograms with vortex phase shift analysis allow to achieve a vertical resolution down to 1,75 nm.

We report on time-resolved photoluminescence studies of Förster resonance energy transfer (FRET) in structures with two arrays of epitaxial Cd(Zn)Se quantum dots (QDs) of different sizes separated by the ZnSe barrier of a variable width. The acceleration of recombination rate of both fast and slowly decaying components of emission from the energy-donating small QDs with the decrease of the barrier width is well consistent with the FRET mechanism. The found Förster radii turn out to be different for the fast and slow components. The rate acceleration is accompanied by the strong suppression of the slow emission component related, presumably, to the dark excitons. These findings open a way to control the characteristic of QD-based devices.

One-dimensional multilayer structures of the periodically alternating low refractive index (silica) and high refractive index (titania) materials have been deposited by sol–gel spincoating. The possibility of creating an optical filter by introducing a structural defect in the form of a layer of double thickness is shown theoretically and experimentally. All experimental spectra are in agreement with theoretical spectra calculated by transfer matrix method.

GaN/AlN quantum wells (QWs) with varied nominal thickness of 0.5-4 monolayers have been studied by time-resolved photoluminescence (PL) spectroscopy. The structures demonstrate an emission peak with the thickness-dependent wavelength in the range 225-320 nm. The observed temporal behavior of PL between 225 and 280 nm can be described as a superposition of fast and slow decaying components with characteristic decay time constants of the order of 0.1-0.7 ns and 7-30 ns, respectively. The fast PL component with the decay time smaller than 1 ns dominates in the thicker GaN insertions and tends to vanish in the thinnest ones, where the slow PL component becomes progressively longer. These observations imply formation in the GaN/AlN monolayer-thick layers of an inhomogeneous excitonic system involving both direct and indirect in space excitons.

Molecular aggregates are well known for their customizable optical properties. Vibronic coupling in monomers forming such aggregates offers rich opportunities for property tuning. We study generic molecular aggregate models of growing complexity (from a dimer up to a decamer) and report how vibronic coupling affects aggregate fluorescence intensity. The total aggregate fluorescence intensity is a measure sensitive to both vibronic coupling and Coulomb coupling between monomer transition densities. Using an exact diagonalization approach in the two-particle basis set, we show how the interplay between Coulomb and vibronic coupling affects aggregate fluorescence. Moreover, for H-aggregates we predict a periodic variation of the fluorescence intensity with aggregate size and show that vibronic interaction decreases the effect.

Surface enhanced Raman spectroscopy (SERS) of fullerene C₆₀ drop-deposited from the 1.4·10^-4 M aqueous solutions on the silvered porous silicon (Ag/PS) is reported for the first time. The used concentration is found to be not detected by the ordinary Raman spectroscopy. It is shown that SERS-spectrum of the fullerene deposited from the air-aged solution are characterized by less intensity than that of the fullerene solution kept out of the air. This indicates degradation of the fullerene solution due to oxidation. The results are prospective for the fast qualitative and quantitative analysis of the fullerene-based materials.

Optical and Faraday rotation spectra of magneto-optical microcavity coated with Au plasmonic layer of gradient thickness were investigated theoretically and experimentally. It was shown that the Tamm plasmon-polaritons mode forms near the long-wavelength edge of photonic band gap. The presence of Au coating of thickness of 90.4 nm increase the Faraday rotation at Tamm plasmon-polaritons and cavity resonances in 1.3 and 7 times, respectively. By transfer matrix method it were found that the incorporation of SiO₂ buffer layer with a thickness in the range from 155 to 180 nm between microcavity and Au coating leads to the strong coupling between cavity mode and Tamm plasmon-polaritons. In this case, one or two resonances arise in the vicinity of the cavity mode depending on the thickness of plasmonic layer. The Faraday rotation for coupled mode in twice less than the value of rotation for single cavity mode.

All-dielectric nanophotonics based on high-index dielectric nanoparticles became a powerful platform for modern light science, providing many fascinating applications, including high-efficient nanoantennas and metamaterials. High-index dielectric nanostructures are of a special interest for nonlinear nanophotonics, where they demonstrate special types of optical nonlinearity, such as electron-hole plasma photoexcitation, which are not inherent to plasmonic nanostructures. Here, we propose a novel type of highly tunable all-dielectric Yagi-Uda nanoantennas, consisting of a chain of Si nanoparticles exciting by an electric dipole source, which allow tuning of their radiating properties via electron-hole plasma photoexcitation. We theoretically and numerically demonstrate the tuning of radiation power patterns and the Purcell effect by additional pumping of several boundary nanoparticles with relatively low peak intensities of fs-laser.

The modification of probability of spontaneous emission for a dipole emitter that placed in Fibonacci lattice-based palindrome structures was examined. Localization properties of eigenstates, that appears in photonic band gaps of palindrome structure was investigated. It was shown, that for a dipole placed in centre of palindrome structure an increase in the spontaneous emission rate will be observed and, in addition, calculated value of Purcell factor is significantly greater than for critical localized states of usual Fibonacci lattices, and close to microcavity eigenmode case.

We have developed the theoretical and numerical modelling of nanoparticle dynamics near planar metallic interface under light radiation. Using our model, we employed the Green's function formalism to simulate the dynamics of nanoparticles under the action of surface plasmon polariton mediated optical forces. By varying the illumination conditions, we determined the different regimes of motion, such as surface attraction and repulsion, and optical pulling regime. We showed that the topology of the trajectories dramatically change, when the surface plasmon polaritons are excited.

X-ray diffraction and NEXAS- and XPS-spectroscopy have been investigated thermostable solid solutions Mn, Cu-doped bismuth titanate with a pyrochlore-type structure. It was shown that manganese and copper in said solid solution of bismuth titanate is present mainly in the oxidation state +2, and titanium - in +4.

We report a proof-of-principle quantum key distribution experiment using a one-way optical scheme with polarization encoding implementing the BB84 protocol. LiNbO₃ phase modulators are used for generating polarization states for Alice and active basis selection for Bob. This allows the former to use a single laser source, while the latter needs only two single-photon detectors. The presented optical scheme is simple and consists of standard fiber components. Calibration algorithm for three polarization controllers used in the scheme has been developed. The experiment was carried with 10 MHz repetition frequency laser pulses over a distance of 50 km of standard telecom optical fiber.

A non-destructive optical control of dynamics of protein aqueous solution drying under different conditions is considered. The processes of organization of different structures in protein films are discussed.

We present the results of hybrid photoconductive antenna THz emission enhanced by silver nanoantenna arrays. By varying the size of nanoantennas and the distance between them, we obtain the greatest value of optical-to-THz conversion efficiency reached so far. The results of experimental investigations are in a good agreement with numerical simulations. The conversion efficiency reveals over 5-fold improvement at certain frequencies, if compared with similar photoconductive antenna without silver nanoparticles, while previous results for this type of antenna barely exceeded 2-fold conversion efficiency gain.

For the first time nanostructures of anodized aluminum oxide (AAO) were synthesized using hydrofluoric acid based electrolytes under potentiostatic mode with varied oxidation conditions. As-grown oxide layers were amorphous and had sponge-like disordered structure with ramified pores system of 50 to 300 nm diameters. All samples under daylight demonstrated blue emission with power up to 10 μW that was seen by naked eye. It was shown that integral intensity of photoluminescence (PL) emission band in 350 – 650 range increases up to 7 – 60 times depending on synthesis details. Observed PL spectra were approximated by superposition of two components with E_max = 2.74 and 2.44 eV, FWHM = 0.63 and 0.53 eV. It was substantiated that studied emission have intrinsic origin and can be attributed to F₂²⁺ - and F₂-centers.

Photolithography mask made of close-packed array of micro- and nano-sized spherical lenses allows to obtain the ordered structures and provides highest "optical resolution/cost" ratio between all existing photolithography and laser direct writing methods. In this letter, we present results of modeling the propagation of a plane wave falling on the array of quartz (SiO₂) microspherical lenses and focusing in the image reverse photoresist layer. We present here experimental results on fabrication of ordered arrays of submicron wells and columns and substrate preparation for growth of monocrystalline nanowires on metal surface using photolithography with mask of SiO₂ microspheres. Such ordered nano-sized arrays of wells and columns can be used in fabrication of further growth of monocrystalline nanowires, quantum dots and production of plasmon structures.