This PDF file contains the front matter associated with SPIE Proceedings Volume 12086, including the Title Page, Copyright information, and Table of Contents.

The effect of UV radiation on the efficiency phototransformation BPA in water in the presence of polypropylene superfine microfibers. The absorption and fluorescence spectra of the investigated substance with three types of PPM of various properties were obtained. After excitation with an excilamp, the main photoproduct BPA fluoresces in the region of 405 ÷410 nm. With an increase in the irradiation time from 0 to 10 minutes, an increase in the fluorescence intensity of this BPA photoproduct was recorded. This indicates that in the course of irradiation, effective photodegradation of the initial toxicant occurs and a photoproduct is formed. In the course of irradiation, the degradation of the resulting photoproducts occurs, which is associated with their adsorption on the surface of the PPM.

An important characteristic of a natural reservoir is the depth distribution of the pigment composition of various groups of photosynthetic organisms and its changes in different seasons, both qualitative and quantitative. In the Arctic zone it is especially important to explore the evolution of natural water bodies under the influence of climate change and the urbanization processes in the region. This paper presents for the first time the study of bacteriochlorophyll (BChl) depth profiles derived from optical measurements accompanied by metagenomic profiling of bacterial communities in two stratified lakes, Trekhtzvetnoe and Elovoe at the Kandalaksha coast of the White Sea. Natural water with microorganisms along with hydrological measurements was sampled from various depths during expedition in March 2021. The metagenomic studies showed that biodiversity indices in both lakes did not appear to significantly diminish with depth. According to the analysis of similarity, differences between samples grouped by the lake of origin were not statistically significant. There were significant differences when samples were grouped by layer of the water column. This suggests that stratification of bacterial communities occurred according to environmental conditions in each part of the water column (oxygenated surface layer; chemocline, and anoxic bottom layers), and was not influenced by the geographical location of the lake. Differences between bacterial communities had strong correlation to changes in redox potential and light penetration, and were weakly correlated with depth and temperature; correlation with salinity and pH was not statistically significant.

In present work, the luminescent YAG:Ce ceramics co-doped with variable compositions of rare earth ions (Dy³⁺, Tb³⁺, Eu³⁺) were obtained by uniaxial pressing methods. Comprehensive characterizations of the microstructure and phase composition of YAG ceramics has been carried out. Spectral-luminescent properties of sintered ceramics were investigated under different type of excitations. The temperature dependences of ceramics have been studied. It was revealed that when the YAG ceramics are heated in the temperature range of 0 – 150 °C, a slight change in the photoluminescence intensity is observed. The highest temperature resistance is demonstrated by YAG:Ce, Dy, and ceramics, the least YAG:Ce, Tb.

The paper presents the experimental results of developing a power supply for metal vapor lasers excitation which include three separate pump sources. Source control is carried out using a PC with developed software, which provides flexible configuration of excitation parameters. The use of three sources allows increasing the excitation power while maintaining comfortable operation conditions for the switch. Waveforms of the sources operation in the separate and simultaneous operating modes are presented. The main parameters of the discharge are estimated.

A computer simulation of the spectral line profiles of the neon atom in an alternating circularly polarized electric field is carried out. The calculations are performed within the framework of a unified theoretical approach based on the numerical solution of the non-stationary Schrödinger equation. The simulation results make it possible to establish a number of regularities in the behavior of the neon spectral line profiles under changes in the electric field parameters. The resonance effects for the neon spectra in the electric field are investigated.

The results of an experimental investigation of the "electrical wind" as a means of convective renewal of gas mixtures in the gas–discharge gaps in CO₂–laser mixtures at superatmospheric (1–12 Atm) pressures are presented. It is established that for a fixed value of the current of a unipolar corona discharge, the speed of the "electrical wind" does not depend on the pressure, but is determined by the chemical composition of the working mixture. The maximum values of the "electrical wind" velocity were achieved in pure carbon dioxide and molecular nitrogen and their values are 3.2 and 2.9 m∙s ^–1. In typical CO₂:N₂:He laser mixtures = 1:1:3 – 1:1:6 the values of the speed of the "electrical wind" are in the range from 2.5 to 1.5 m∙s ^–1. It is reported about the design and generation characteristics of a small–sized sealed–off metal–ceramic CO2 laser of superatmospheric pressure with an "electrical wind" operating at pulse repetition frequencies up to 25 Hz. At an operating pressure of 12 atmospheres and the excitation zone of the volumetric pump discharge V =18∙0.8∙0.8 cm³ achieved the maximum radiation energy in a pulse of 0.8 J with a duration of up to 10 nanoseconds.

The conditions for the formation of stable volume discharges at atmospheric pressure in CO₂–laser mixtures with an increased content of carbon dioxide and providing the generation of laser radiation pulses in the form of a "giant peak" with a base duration of up to 100 nanoseconds and a radiation energy of up to 1.5 J are determined. With the help of a selective resonator, a discrete rearrangement of radiation on individual vibrational–rotational transitions in the wavelength range of 9.2–10.8 μm is realized. The operation of the TEA–CO₂ laser at pulse repetition frequencies up to 50 Hz is ensured.

The influence of the structure of the electrodes on the attainment of the maximum pulse repetition rates and the level of the average radiation power in TEA–N₂ lasers is studied. It is shown that the use of sectioned cathodes promotes the formation of volumetric discharges at increased pulse repetition rates. The use of a cathode structure in the form of a set of pins with individual excitation of volume discharges in each gap, together with the use of preliminary ionization of gas mixtures by VUV radiation, ensures that the maximum pulse repetition rates of up to 10–12 kHz in N₂:He mixtures are achieved. The maximum average radiation power of 6 W was achieved at a pulse repetition rate of 5 kHz for an N2:He mixture with an optimal component ratio of 30:730 at a total pressure of 760 Torr.

XeCl electro-discharge laser modeling is discussed. The pump parameters of a LC-contour excitation system are studied in XeCl laser using a Ne:Xe :HCl mixture. A computation model is developed for finding the parameters of laser. The dependence of generation energy from parameters of excitation system and mixture was determined.

We report on our recent approaches focused on the formation of a new class of subwavelength scale self-bending light beams, discovered in 2015, in application to in-plane surface plasmon. For the particle with broken symmetry (Janus particle) the morphology of the field localization area depends on the orientation of the particle that resembles the two faces of “Janus bifrons”. Photonic hook (PH) light do not propagate along straight line but instead follow curved trajectory. Wavefront analysis of such asymmetric mesoscale structure reveals that the unequal phase of the transmitted plane wave results in the irregularly concave deformation of the wavefront inside the structure that then leads to creation of the PH. Such dielectric structures enabling the realization of ultracompact wavelength-scaled and wavelength selective new inplane nanophotonic components.

The paper reports the results of initial research on the creating of a new laser active element based on manganese aluminate spinel. A technique for preparing iron-doped manganese aluminate spinel is described. Nanopowders with different Al/Mn ratios were obtained by laser ablation followed by vapor condensation in a carrier gas flow. It was found that the particles had an average size of 16.5 nm and a narrow (about 40 nm) size distribution. The compacts prepared from these nanopowders with a diameter of 14 mm and a thickness of 2 mm had a density of 50% of the theoretical one. The compacts were sintered in a vacuum at a temperature of 1300 °C for 3 hours. It is shown that to obtain a single-phase spinel, the molar ratio of Al/Mn cations in the nanopowder should be 1.2–1.75. The transmission spectra of the samples were measured and a transmission range of 2–8 μm and 5 absorption bands were found and the diagram of the lower levels of Fe²⁺ was plotted.

For study of photodegradation, an excilamp on working molecules KrCl with ^λ_rad = 222 nm, developed at the Institute of High Current Electronics of the SB RAS, was used as source of UV radiation. The results of direct photolysis of phenoxyacetic acids herbicides in aqueous solutions are discussed. The phototransformation occurs more slowly when the herbicides concentration increases. The use of the flow-through reactor is more effective than operation in the stationary conditions. The prospect of using a wide range of excilamps with different characteristics for solving environmental problems is highlighted.

In this work, the luminescence properties of three europium complexes with ligands based on 2,2’–bipyridyldicarboxylic acid with various counterions (TFA, NO₃, Cl) were studied in the form of powders and acetonitrile solutions. Their luminescence spectra were recorded at room temperature and in liquid nitrogen. We obtained and calculated the following luminescence characteristics: luminescence lifetime, relative intensities of each luminescence peak, asymmetry coefficient, radiative lifetime, internal quantum yield, luminescence quantum yield, and the effectiveness of sensitization.

Atomic and electronic structure of Bi₂SiO₅/β-Bi₂O₃ hetero-junction was described by means of density functional theory. The interface was found to be narrow-gap semiconductor with indirect band gap. The redistribution of states near the Fermi level in hybrid structure and the impact of spin-orbit coupling are discussed.

The influence of the structure of phosphonic acid esters on the stability of their terbium complexes was studied. It was shown that one complex particle was formed irrespective the nature of the side ester chain, and the metal-ligand stoichiometry of the complex was 1:1. The stability constants of the terbium complexes were determined. An increase in the size of the bulky substituent leads to an increase in the stability of the complexes.

The purpose of this work is to explore the effects of laser radiation on pigments based on titanium dioxide by changing its parameters. A qualitative assessment of the results of the experiments showed that laser irradiation of the pigment in solutions with concentrations from 10% to 1×10-2%, λ = 1024 nm, τ = 750 ps and an energy density of 8.7 J/cm² leads to an increase in the turbidity of the solution and its whiter shade. Analysis of images from a microscope showed that pigment destruction is observed. Overall, the principle of destruction of the white pigment in the laboratory was proposed and the feasibility of further in vivo testing was evaluated. As a result of the research, an obtained data will serve as the foundation for the development of methods for removing white pigments for tattoos and will increase the effectiveness of permanent makeup removal.

Multiple filamentation in air of high-power ultrashort laser radiation with transverse intensity profile resembling a “corona-beam” (CB) composed by incoherent combining of several annularly distributed independent top-hat sub-beams is theoretically considered. Through the numerical solution of time-averaged nonlinear Schrodinger equation, we study the spatio-angular dynamics of synthesized near infrared CB along the optical path by varying the number and peak power of the beamlets. The evident advances in the multiple-filamentation region manipulating of synthesized CB are demonstrated. Particularly, by adjusting the number and aperture of the constituting sub-beams it makes possible to significantly delay the filamentation onset distance and increase the filamentation length in air.

The results of experimental and theoretical studies of behavior spectral profile of second harmonic (SH) radiation with a central wavelength of 475-477 nm during its formation in a nonlinear KDP crystal, depending on the phase matching angle and radiation intensity are presented. It is shown that a change in the propagation angle of fundamental radiation to one or the other side of phase matching angle by 16– 20 min leads to a spatially inhomogeneous broadening of the second harmonic spectrum up to two times and a shift of its maximum (averaged over the beam cross section) to shorter wavelengths from the central wavelength.

The paper presents analysis results of large aperture stretcher schemes for use in laser systems after pre-amplification stages. To increase output peak power in the two-channel femtosecond laser system with coherent field combining, developed at ILP SB RAS, a stretcher for deployment in front of additional amplification stages is required. The stretcher and additional stages will boost pulse energy in a channel up to 1.5 J. Since beam energy at stretcher input is 100-150 mJ, beam diameter exceeds 20 mm what, is determined by damage thresholds of stretcher elements. With a stretching ratio of 105 and such an aperture, aberrational distortions of the stretcher obstruct further compression, focusing, and effective coherent combining of amplified pulses. Optimized parameters of the off-axis and off-plane Offner stretchers allow pulse stretching to 2.1 ns (spectrally limited duration ~20 fs and carrier wavelength 0.83 μm) and subsequent recompression down to 24 fs and 35 fs in a beam with 20 mm aperture.

A comparative analysis of various focusing schemes for few-cycle femtosecond pulses in collinear and non-collinear geometries is carried out. Focusing with a parabolic mirror is considered, as well as spherical (mirrors are located on a sphere, beams are focused to the center), ring (beams in one plane are focused to the center), 2 row ring geometries. It is shown that in the noncollinear scheme there is an optimal number of beams, depending on the chosen geometry, at which the maximum intensity is achieved. The spatial contrast and the space-time distribution in a focused beam with coherent combining are analyzed. The Monte Carlo method is used to study the influence of the parameters of the beams being combined, such as aberrations and angular instability on the efficiency of coherent combining in collinear and noncollinear geometries.

The propagation of high-power femtosecond laser radiation through an aerosol is considered. The propagation of high-power femtosecond laser radiation is simulated by passing through flat phase screens that simulate the passage through an aerosol. They have effective optical parameters corresponding to the properties of aerosol, which are found, respectively, for different values of intensity levels in the case of nonlinear interaction from the solution of the direct problem.

Evolution of local instability in a ring vortex beam propagating in the turbulent atmosphere with highest nonlinearities of the refractive index as well as in uence of the effective characteristics of the light beam is investigated based on numerical calculation of the nonlinear Schrodinger equation with high-order nonlinearities. Propagation of high-power femtosecond laser radiation (HPFLR) with topological charge in the random medium under overlap of an amplitude-phase mask and an original beam is considered. Depending on the mask configuration and initial radiation power, rotation of the beam can lead both to converge and growth more distant of filamentation beginning as well as extension of filamentation area by two and more times.

Lasing characteristics of solid-state active media based on Chromen 3 (Ch-3) in polymethylmethacrylate (PMMA) were investigated such lasing at full width at half maximum (FWHM), Spectral width and output power. Comparing between the lasing characteristics based on resonator’s geometric parameters were investigated.

Computational and theoretical study of the dynamics of the formation of a quasi-neutral proton beam propagating from the rear surface of an aluminum target under the action of super-intense laser pulse is presented. It is shown that total time to establish the quasi-neutrality of the proton beam is about two laser pulse durations. The calculated values of the effective temperature and the number of fast protons are close to the experimental results¹.

The article presents the results of studying the horizontal orientation of crystalline particles, carried out using a scanning polarizing lidar LOZA-M3. Several series of measurements of the ice cloud structure in the zenith scan mode were carried out in Tomsk in May-July 2021. The dependence of signal intensity at small tilt angles (up to 5°) reflects the distribution of particle deflection relative to the horizontal plane, and is well described by the exponential dependence. Scanning up to angles of 45-50 degrees showed a high probability of the existence of the corner reflection in ice clouds.

Substances with different absorption spectra have different backscatter spectra. If the range of sounding wavelengths is narrow, but includes evident absorption bands of an aerosol substance, then this substance can be detected from the backscattering spectrum. This is a ground for the use of the differential scattering (DICS) technique for the detection of known organic compounds in natural and anthropogenic aerosol. CO₂ lasers with the wavelength tuning range 9–11 μm, which includes the absorption bands of many organic substances, are apparently the most suitable for DICS implementation. It should be borne in mind that when the imaginary part of the refractive index changes (for example, when an absorbing substance is added to a water drop), the real part of the refractive index is also changes. For large particles (r ≥ 10 μm), even small changes in the refractive index significantly affect the backscattering efficiency. The accuracy of the literature data is insufficient for preliminary (a priori) calculation of aerosol backscatter coefficients. Therefore, the development of DICS requires extensive field measurements and their complex mathematical processing with the use of machine learning algorithms. This research sets out the task of systematization of the backscattering radiation by atmospheric aerosol with different organic substances and finding out the wave lengths where the backscatter signal is higher than the selective and continuum atmospheric molecular absorption.

In this work, photodetectors with a built-in cooling system based on Peltier elements and with a cooling system based on a Dewar flask filled with liquid nitrogen are experimentally studied with the aim of practical estimation and comparison of capabilities of the photodetectors with different photosensitive element cooling types.

The numerical three-dimensional non-stationary model based on balance equations and the thermal conductivity equation was used to study the dynamic of laser amplification process in Yb:YAG media. Characteristic curves for gain and optical phase difference are obtained, and it is shown that it is possible to minimize wavefront aberrations in amplified radiation while keeping high gain coefficient by choosing optimal pump parameters. Transversal doping profiles are proposed for decreasing of losses arising from amplified stimulated emission.

The results of an experiment on formation of a scalar vortex beam in the system of coherent combining of fiber laser beams are reported. Stabilization of phase relations between optical beams is achieved by placing a helicoid phase forming diffraction optical element (DOE) made as a phase plate with helical phase profile in the active feedback loop. Time-stable vortex beams with the topological charge p = ±1 are obtained. The vortex character of the obtained beams is confirmed by the results of interferometric measurements.

The main characteristics of a three-mirror laser resonator (mode selectivity, resonance radiation divergence) are theoretically investigated. The resonator cavity contains two spherical mirrors that make up an unstable confocal resonator, and one flat semitransparent mirror, which is located perpendicular to the unstable confocal resonator optical axis. A flat mirror returns part of the radiation into confocal resonator cavity. It is shown that the considered three-mirror optical system as a laser resonator combines the properties of both unstable and stable resonators. The intensity of the focused beam with a Fresnel number of ~10, which is formed by an optical transmitter with a three-mirror resonator, is ~10% higher than in the case of a system with a two-mirror resonator. The results of this work can be used in development of large-size lasers with a low-gain active medium.

The main characteristics (power loss and selectivity, resonance radiation divergence) of a two-mirror unstable resonator with a variable geometric configuration are investigated in the diffraction approximation based on the Fox-Lee equations. A cavity of an unstable confocal geometric configuration was adopted as a basic. At that, the control of the configuration of the resonator and resonance radiation is realized by deforming one of the mirrors (either a concave reflector or a convex counter-reflector). In this work, a comparative analysis of the active resonators characteristics with a deformable reflector and a deformable counter-reflector with the same functions of deformation is carried out. It is shown that, depending on the resonator specific technical parameters and the required power losses, the required concave reflector deformations amplitude in some cases is up to ~ 10% less than in the case of counter-reflector deformations. The mode selectivity of the considered active resonators is practically the same. The considered algorithms for controlling the shape of deformable mirrors make it possible to vary the resonator power losses and control the output laser radiation power over a wide range while maintaining the optical quality of radiation close to diffraction. The results of this work can be used to optimize the scheme and parameters of a laser with a controlled output radiation power.

The results of experimental modeling of a wireless optical communication channel in an aquatic environment are presented, which were carried out on the basis of a laboratory installation for underwater communication, developed at MTUCI. The possibility of creating cheap and compact optical communication systems for high-speed data transmission at distances up to 100 m has been demonstrated. The necessity of using the technology of quantum key distribution for information security is shown. The key elements required for the implementation of the quantum distribution of cryptographic keys in the ocean are analyzed.

The scattering matrixes for randomly oriented large particles of faceted shapes have been calculated using both the geometrical optics and physical optics approximations. We showed that the scattering matrixes are different for regular and irregular particle shapes since the corner reflection effect is predominant at the backward direction for the regular shapes. In the case of irregular shapes, the scattering matrixes have the common feature. Namely, the elements of the matrix reveal near the backward scattering direction some typical peaks that are explained by interference of the backscattered waves. In particular, the negative polarization effect known in astrophysics can be explained by the interference.

In view of the current booming LiDAR systems and the trends of the future market, this paper first introduces the mainstream manufacturers in real-time sensing LiDAR, as well as their products. Combining with different requirements in application, characteristics, and current situation of different LiDAR technical systems. Then, the research progress in railway perimeter real-time monitoring of the LiDAR team from the Institute of Microelectronics is presented. Finally, the application trend and development prospect of real-time sensing LiDAR are summarized and forecasted. To meet the evolving demands, real-time sensing LiDAR will be further advanced to low cost, high performance, product seriation, device miniaturization, fixation and multi-source integration, etc. The system has been applied to protect railway security.

A possibility of monitoring of the operating mode of the plasma emitter of electrons of a pulsed accelerator (300 keV, 0.5 μs) is considered on the basis of the analysis of the visible radiation spectrum in the region of the accelerating gap. The spectrum was recorded using the optical system of a complex diagnostic device for controlling the parameters of the vacuum diode of the accelerator and spectrometer, the optical probe of which is mounted opposite the accelerating gap and is protected from the direct action of an electron beam. Characteristic visible spectra were recorded in the region of the accelerating gap for cathodes made of common structural materials (copper, graphite, and stainless steel), which makes it possible to distinguish between the electron beam generation mode and vacuum gap short-circuiting mode.

Nowadays, laser ranging is widely used in industrial and security fields. As one of the most well-known pulse laser detection system, Lidar is a much effective equipment for environmental recognition. Currently, research on autonomous and smart vehicles technology has been growing exponentially in recent years by integrating more and more smart hardware or software inside. Most studies are almost based on non-real-time operating system with random delays, which leads to lag and inaccuracies in the received data. Based on a self-developed three-dimensional Lidar, a smart embedded system for real-time data transmission on the FPGA Zynq is proposed. The real-time signal acquisition and transmission system is implemented and verified in the three-dimensional imaging experiments system. In this system, verilog code is applied for Lidar data control acquisition and transmission. C/C++ code is used for data calculation and uploading the point cloud data to the computer through the network to realize the real-time display of point cloud. Experimental results demonstrate that the Lidar data are correctly read by the FPGA board. In addition, the real time data acquisition meets the requirements of control and real time data acquisition and procession at 20fps. The proposed approach provides a very useful basic platform for many applications using Lidar as a sensor and will improve their detection accuracy.

The paper considers the equipment and methodology for remote determination of the vertical distribution of atmospheric temperature up to altitudes of 90 km. The technique is based on the lidar measurements of the vertical profile of the molecular density of the atmosphere using the Rayleigh scattering effect. The results obtained on the modernized Rayleigh scattering channel of the lidar based on the main mirror of the Siberian lidar station with a diameter of 2.2 m are discussed. A two-stage procedure for the remote estimation of temperature by molecular backscattering is proposed, which makes it possible to estimate the temperature both in a free atmosphere and in a cuvette in which the relationship between the temperature and pressure does not fit into the barometric model. Calculations have shown that the accuracy of the temperature profile retrieval depends on the choice of the calibration point and its error. The calculation of the profile by formula, when the calibration point is chosen at the upper part of the sounding path, has greater stability and accuracy compared to calculations by formula with the calibration point chosen at the beginning of the path.

Using an electrode with a ceramic coating, a new method for the formation of an apokampic discharge in the pressure range of 30-150 Torr has been obtained. It was found that the average plasma bullets velocity propagated from such an electrode can reach 520 km/s. The results obtained are in good agreement with the simulation results obtained earlier in the framework of the streamer model.

Narrow-band ultraviolet B radiation is increasingly used in the therapy and recurrence prevention of autoimmune skin diseases. The popularity of this method stems from the relative safety and minimal impact on the human body during physical therapy. This paper reports on the development of a unique design of the excimer lamp equipped with a UVB dose control system, a sensor control unit with a ribbon software interface, a quick positioning system, and an electronic patient logbook. The excimer lamp is designed to provide safer and more effective UVB therapy for skin psoriasis, nail plate psoriasis, vitiligo and atopic dermatitis.

The change in the shape of xenon dimers second continuum spectrum (^3,1Σ⁺_u→¹Σ⁺_g), excited in a barrier discharge (P = 300 Torr), depending on the gas temperature is studied. It was found that an increase in the gas temperature from Т = 500 K to 1300 K leads to a broadening of the continuum at half maximum from Δλ = 15 nm to Δλ = 20.5 nm and a shift of its maximum to the short-wave region from λ = 173.2 nm to λ = 172.5 nm. The relative increase in intensity occurred in the short-wavelength wing, while the position of the short-wavelength continua boundary did not depend on temperature.The shape of the second continuum of krypton dimers experienced much smaller changes under similar excitation conditions, which was explained by the lower heating of the gas and the lower change in the relative population of the vibrational levels.

In the past few years, it has shown that photonic jet – a high-intensity near-field focus can be curved through focusing of an asymmetric mesoscale dielectric particle. This unique electromagnetic beam configuration breaking spatial symmetry was termed ‘photonic hooks’ and demonstrated different features from Airy-family beams using a relatively simple experimental setup. The measured radius of the photonic curvature it creates approximates to half of the wavelength, which is the smallest curvature of electromagnetic wave ever reported. This effect was discovered in many relevant fields, including near-field optics (both in transmitted and reflection modes), terahertz (THz) radiation, in-plane plasmonics, and acoustics, and this paper is a short review for them.

The results of an experimental study of the processes of resonant interaction of short pulses of polychromatic radiation of a dye laser with plasma of a nanosecond discharge in neon in an extended cylindrical shielded discharge tube are presented. The formation of asymmetric optical dispersion-type transmission spectra of plasma with light amplification at the shortwavelength or long-wavelength wing of NeI absorption spectral line with a wavelength of 650.6 nm is discovered. The conditions under which the amplification of light on the short-wavelength wing of the spectral line is replaced by the amplification of light on the long-wavelength wing of the given spectral line are experimentally determined. For the investigated design of the discharge chamber, a numerical simulation of the dynamics of the space-time distribution of the density of absorbing atoms in the process of nanosecond electrical breakdown of neon was carried out in the Comsol Multiphysics software package. The mechanisms of a possible connection between the character of the longitudinal spatial inhomogeneities of absorbing atoms and the asymmetry of the profile of the plasma transmission spectrum in the area of anomalous dispersion are discussed.

To protect photosensitive detectors and micro-optoelectromechanical systems, protective equipment is needed against the ingress of powerful laser radiation. Conventional color filters pose a problem for such devices by cutting out the region of the spectrum in which the laser operates. To ensure the possible operation, passive limiters based on nonlinear optical effects can be used. They are capable of transmitting non-hazardous laser radiation with insignificant attenuation (transmission of the order of 70%), and when hit by powerful laser radiation they can quickly darken. The urgency of this problem only increases with the development and widespread use of laser systems. In particular, when using lidars, receiving photosensitive detectors are often damaged. The use of various conjugates with carbon nanotubes is promising for creating limiters. In this work, it is proposed to use conjugates of dimeric phthalocyanine complexes of Cu to create nonlinear optical materials. This material demonstrates the ability to attenuate laser radiation with a nanosecond duration of 16 ns, even in the case of single pulses, due to the synergistic effect of absorption and scattering of radiation. In addition, in the case of 140 fs femtosecond periodic radiation, with a pulse repetition rate of 80 MHz, this material demonstrates the attenuation of radiation when using a cut-off diaphragm due to the effect of self-phase modulation (SSPM). The characteristics of the SSPM pattern were studied, it was noted that the outer rings have the greatest width. In general, the width of the rings gradually increases with distance from the center of the beam. At the same time, the peak fluence (highest fluence value) of each ring is approximately the same, with the exception of the central part. In the central region, a strong effect is observed from heated flows tending upward and thus strongly violating symmetry.

Potential efficiency of the THz wave generation by down-conversion of the visible emission in nonlinear β-BBO crystal is estimated. Eight types of interactions are found possible. Four interaction types were realized in the carried-out experiments. Optical damage threshold under fs pumping was estimated.

We present the thorough studies of dielectric properties of BiB₃O₆ (BIBO) crystal in the subterahertz range. We observe a large birefringence Δn = n_Z −n_X = 1.5 and the values of absorption coefficients of all three axes to be less than 0.5 cm⁻¹ at the frequency of 0.3 THz. The difference from visible range in angle Φ between the dielectric axis z and crystallophysical axis χ is found to be more than 6°. The simulated phase-matching curves in the xz plane of the crystal show the optimal value of the angle θ to be around 25.5°±1° for an efficient millimeter-wave generation under the pump of 1064 nm laser radiation.

The results of experimental studies of conditions for THz emission generation in laser filament created by focused ultrashort laser pulse of Ti: Sapphire complex are presented. The influence of magnitude and direction of applied external electric field, energy and polarization of pump radiation in one- and two-color optical schemes on the intensity, divergence, and polarization of THz radiation are investigated. THz spectra is estimated and optimal generation conditions are discussed.

In the modern world, it is worth seriously thinking about the quality of food consumed. Eating livestock products, we often do not think about such things as the presence of antibiotics in them. However, this can have serious consequences for the body. That is why the sanitary services of all countries pay such attention to the definition of antibiotics. Somewhere very strict standards are set on them. This article is an overview of such antibiotics as sulfaguanidine, benzylpenicillin and chloramphenicol, we also discussed the methods for the determination of antibiotics, methods of fluorescence analysis and quantum chemistry, which we will use in future studies.

The heating dynamics a micron-sized two-layer capsules simulating transport microcontainers with water-containing load and light-absorbing composite shell exposed to a near-IR laser pulse (wavelength 800 nm) is theoretically studied. Both single microcapsules and the microassemblies of particles with various spatial shapes and different packing densities are considered. Using FDTD and FEM calculations, the numerical simulations of the optical field distribution inside and near the microcapsules are carried out, and the temporal dynamics of the temperature profiles of microparticles shells is obtained. Based on the simulation results, one can conclude that the particle morphology introduces specificity in the spatial profile of the optical field and the distribution of light absorption regions. Variation in the geometric shape of a capsule leads to dramatic changes in the distribution of absorbed light energy and, accordingly, particle temperature field. In order to increase the efficiency of absorption of optical radiation in capsule volume and to obtain the maximum heating of absorbing shells, the capsules of cubic, cylindrical and partly rectangular shapes are preferable. Thus, having a 100-fs laser pulse with energy of only 20 μJ it becomes possible to heat a cylindrical microcapsule to the temperature of thermal destruction of its polymeric shell (~ 410 K). Worthwhile notice, the water-filling of a capsule core remains cold. At the same conditions, the ellipsoid-shaped capsule is heated to multiple lower temperatures (~ 340 K).

This work continues the cycle of our research on the physiological effect of UVB radiation on plants. The physiological effect of UVB radiation (308 nm, doses of 0.5, 1.4 and 2.7 J/cm²) on the structural and functional characteristics of wheat seedlings was determined. With an increase in the radiation dose, a decrease in plant height, leaf area and the amount of photosynthetic pigments was revealed, photosynthesis parameters decreased, and the content of low-molecular- weight antioxidants increased. This means that UVB priming of wheat sprouts should be carried out at even lower doses than were selected in the experiments.

This article describes the methods and approaches used by us to solve the problem of a high error in the determination of a component with a low concentration in a gas mixture. The approaches based on the modification of the machine learning model were considered, the approach to the generation of the training sample was changed, an iterative method for increasing the accuracy of the model results was proposed.

The treatment of bean seeds with epibrassinolide (the preparation “Epin-Extra”) resulted in the increase in fluorescent parameter (F_M−F_T)/F_T of plants grown from these seeds, indicating the increase in the photosynthetic activity of the plants. The treatment of bean seeds with epin led to the increase in chlorophyll content and also in the acceleration of plant growth. Fluorescence quenching after switching on the actinic light in experimental plants was faster than in control ones which may indicate increased adaptive capabilities of the photosynthetic apparatus.

The paper presents an algorithm based on low order statistics for the informative feature extraction for Raman spectroscopy data. The proposed method was tested on mouse preimplantation embryos Raman spectra. Both supervised and unsupervised machine learning methods were applied to selected the most informative features to test the separability of the processed data.

The work is devoted to identifying the features of plant growth and development under laboratory conditions after presowing stimulation of seeds of pine (Pinus sylvestris L.), thuja (Thuja occidentalis L.) and eggplant (Solanum melongena L., variety "Universal") by UVB radiation of XeCl-excilamp. In all cases, conditions were identified in which UVB stimulation accelerates the germination of these seeds and the formation of seedlings. Additionally, microcoping of germinating 10-day-old thuja seeds performed on sections shows that the seeds show clear differences compared to the untreated control. If in the control, the seeds were just beginning to germinate (the appearance of the germ root), then in the experimental samples, on average, 5% of the seeds passed to the stage of development and formation of the seedling, had a developed root, hypocotyl, colored cotyledons, which began to shed the seed rind. The obtained primary data confirm the prospects of using narrow-band UVB radiation of XeCl-excilamps for pre-sowing stimulation of plant seeds.

Two-photon microscopy methods have been actively developing in the last two decades. In particular, various approaches are being developed to analyze metabolic activity obtained by laser microscopy with high temporal resolution. One such approach is ploting the autofluorescence lifetime signal data to the phasor plot and observe deviations from the normal state. This tool has proven itself well for analyzing the metabolic activity of biological objects, including bacteria. This study analyzes the antimicrobial activity for MRSA bacteria by phasor plot approach. It was possible to show that, the lifetime of autofluorescence in the phasor plane changes depending on the type of nanoparticles used, with which bacteria are incubated. This result can be used in the future for rapid assessment of the antimicrobial activity of nanoparticles.

CARS method was used to study the interactions of biomacromolecules with carbon dots synthesized by the hydrothermal method. A significant effect of CDs on molecular bonds in DNA chains during their interaction in water was found. As a result of the analysis of the obtained CARS DNA spectra before and after their interactions with nanoparticles in water, markers were identified that indicate the presence of oxidative stress on DNA strands in the presence of CDs.

In the work were investigated the effect of vacuum ultraviolet (VUV) radiation (λ=147 nm, 173 nm) on the DNA of microscopic fungi spores of the species Rhodotorula colostri, Aurobasidium pullulans (colored and uncolored types), Cladosporium herbarum containing different types of protective pigments. The DNA molecules inside the spores (in vivo) and isolated from them (in vitro) were irradiated. The results of electrophoresis showed, that VUV irradiation leads to the appearance of light DNA fragments with sizes 100-750 base pairs, as well as high molecular weight fragments containing more than 20 000 base pairs. The greatest features were observed during the irradiation of Rhodotorula colostri DNA: 1) were formed longer fragments (100-750 base pairs); 2) at λ=172 nm threshold effect was observed: DNA destruction appeared starting from radiation energies of 35 mJ/cm² during in vivo irradiation and, starting from radiation energies of 20 mJ/cm², during in vitro irradiation; 2) when irradiated at the wavelength λ=147 nm, the relative destruction of DNA increased, while for other types of the spores it fell. These features can be explained by the presence in Rhodotorula colostri spores of carotene capable of exercising both the properties of the antioxidant and to produce reactive radicals. When irradiated at a wavelength of λ=173 nm in vivo and in vitro, each type of spore had the same characteristic features, which may indicate a small effect on DNA of free water molecules photolysis products. When irradiated at the wavelength λ=147 nm, the influence of melanin was observed: in melanin containing spores the results in vivo and in vitro exposure had the same characteristic features, in the spores without melanin- differed. In the first case, this can be explained by a smaller concentration of reactive radicals due to VUV radiation absorption by melanin, in the second - participation in the DNA destruction of free water molecules photolysis products. A common feature of the electrophoresis results was the presence of long DNA fragments of about 20,000 base pairs in all types of spores. The brightness of these fragments correlated with the DNA destruction degree.

Raman spectra of blood plasma were studied in the dynamics of the experimental glioma. We used a DXR Raman Microscope (Thermo Scientific), excitation wavelengths of 532 nm, range 80–3200 cm^–1. Each sample of blood plasma was a droplet with a volume of 10 μL placed on a special aluminum plate. Machine learning methods were used to identify the most informative frequencies associated with cancer molecular markers. The most significant changes in the Raman spectra are observed in the 900–1700 cm_–1 range.

The results of experimental studies of various generation modes of runaway electron beams (RAEBs) are presented. The main attention is paid to the mode when the RAEB with the highest amplitude are generated in air at atmospheric pressure. Other modes are discussed too: the most implemented and often mentioned by other authors generation mode as well as the mode when RAEB is generated after breakdown.

The design and application of a multichannel fiberoptic system for recording (MSR) of dynamic, spectral and energy characteristics of radiation sources in the range of 10^-10-10^-8 s is considered. Simultaneous recording of radiation characteristics in different areas of the object under study provides extensive information capabilities and ease of operation. The total number of fiber-optic channels is 12, of which 9 are designed to register the dynamics of radiation. The dynamics of the radiation is recorded by a developed multi-channel high-speed electron-optical camera with a resolution of 40 to 200 ps, depending on the type and length of the optical cable. The maximum resolution of the spectral equipment in the range of 500-700 nm is 0.06 nm. Transient processes in electrical and optical channels of radiation detection are considered. The possibilities of using MSR to study the dynamics of luminescence along the discharge channel in gases and semiconductors excited by sub-nanosecond pulses of an electron beam or an electric field are shown. During the studies the dynamics, spectrum and energy of the radiation were simultaneously recorded. The results of experiments and the possibilities of using MSR in the study of high-speed processes are discussed.

Using emission spectra, the electronic, vibrational, rotational, gas temperatures and the reduced electric field strength at different distances along the propagation of the apokamp from the discharge channel at an air pressure of 150 Torr, a voltage of 7.6 kV, and a frequency of 37.5 kHz were determined. To determine the above values of plasma parameters, the methods of optical emission spectroscopy were used, after which the experimentally obtained values were compared with the values obtained in the course of modeling the emission spectra of the discharge plasma using a code based on the radiation-collisional plasma model. It is shown that the values of the electron temperature and reduced field strength increase abruptly at a height of ~ 12 mm above the discharge channel, marking the transition from the offshoot zone to the positive streamer zone. The gas temperature along the distribution of the apokamp decreases exponentially and at a distance of 75 mm reaches about 530° C (which is about 3 times less than at the base of the apokamp). The data obtained are in agreement with the streamer model of the plasma plume of the apokamp and allow us to hope for the creation of a plasma source based on an apokampic discharge with a moderate gas temperature at the end of the plasma plume.

The study of exciton cathodoluminescence in diamond is not only scientific but also practical importance. Ultraviolet radiation at a wavelength of 235 nm can be used for disinfection, activation of surface reactions, photochemistry, and more. Thus, diamond is a promising material for creating a cathodoluminescent source of ultraviolet radiation. We have investigated the temperature dependences of the exciton cathodoluminescence spectra of single-crystal diamond in the temperature range from 80 to 400 K. The temperature dependences showed a characteristic increase in the intensity of exciton cathodoluminescence in the range 230-240 nm with increasing temperatures from 80 K to 150- 180 K. Further increase in temperature to room temperature (297 K) leads to a twofold decrease in the radiation intensity. With a further increase in temperature to 400 K, no change in the cathodoluminescence intensity was observed within the error

Human health is seriously endangered by economically motivated adulterations of food stuffs, in general, and fruit juices, in particular. Additional advances are needed in trustworthy techniques for the fast recognition of fraudulent ingredients in the supply chain. After more than a decade of application of laser photoacoustic spectroscopy (LPAS) to food fraud detection with CO₂ lasers, the Diagnostic and Metrology Laboratory of ENEA realized a portable and easy system based on a quantum cascade laser (QCL). Juice adulteration was used as a case study to evaluate its performances. Chemometrics tools demonstrated that the instrument was able to sense in a few minutes two adulterated juices.

The effect of the amplitude and spatial frequency of a sinusoidal wavefront over a square aperture on the far-field diffraction pattern is considered for a laser beam. An analytical solution of the Fraunhofer diffraction problem for a 2D sinusoidal wavefront over a rectangular aperture with an arbitrary integer number of periods along each side is derived using an original technique. The result coincides with high accuracy with a numerical solution obtained using the Fast Fourier Transform. It has been shown that after correcting the second-order Zernike modes by a stacked array piezoelectric deformable mirror with different numbers and patterns of control actuators, the residual wavefront aberrations may be considered approximately sinusoidal. Therefore, the results for an ideal sinusoidal wavefront could be applied to a real residual wavefront in problems of adaptive optics. For sinusoidal aberrations, the so-called beam quality β factor has been shown to increase sharply as the root-mean-square wavefront error (RMS) passes certain values. A new criterion of wavefront quality for sinusoidal and residual aberrations over a square aperture has been proposed.

The study of short-lived induced (singlet-singlet) and long-lived induced (in particular, triplet-triplet) absorption capacity of crystal violet (CV) in various solvents was carried out by the pump-probe method. Water, dimethyl sulfoxide, isopropyl alcohol, and ethyl alcohol were selected as solvents. The formation of triplet states in various CV solvents was revealed upon excitation by nanosecond radiation of the 4th harmonic of a Nd: YAG laser (wavelength 266 nm, average power – 25.5 mV, repetition frequency – 3 Hz, pulse duration – 10 ns, peak power – 10-12 MW/cm²). It is shown that the spectrum of the induced CV absorption in ethanol contains two closely spaced bands at 400 and 485 nm. Short-lived and long-lived induced CV absorption in isopropanol at room temperature (λ_max=400 nm) was recorded. Keywords: crystal violet (CV), induced absorption spectra, spectroscopy, pump-probe method.

In this work, self-seeded lasing pulse duration of the В²Σ⁺_u – X²Σ⁺_g transition of molecular nitrogen ion in air laser plasma at different pump pulse focusing conditions was investigated. Pumping was carried out at the central wavelength of 950 nm, with 60 fs duration (FWHM), and 10 mJ energy. It was shown that lasing pulse duration increases from 1.15 to 4.6 ps, and unsaturated gain coefficient decreases from 6.7 to 4.2 with decreasing pump pulse intensity when geometrical focus length was increased. An explanation for picosecond lasing duration at femtosecond seed amplification is proposed.

Recently, there has been an increased interest in natural polysaccharides, in particular, chitosan, which are widely used in medicine and industry. Chitosan labeled with fluorescein dyes acquires additional optical properties that can be used in sensing and delivery systems. Mechanism of binding of a polymer to a label largely determines the field of its possible applications. The quantum chemical calculation using the B3LYP/aug-cc-pVDZ theory level has been made in order to contribute to the understanding of intermolecular interactions. The geometry of fluorescein, eosin Y, and erythrosin B in the dianionic, monoanionic, and neutral quinoid forms interacting with chitosan has been optimized and the absorption spectra have been calculated using the time-dependent density functional theory taking into account the solvent. The comparison of the calculated absorption spectra with the experimental data has shown a major role of the electrostatic mechanism in binding of anionic dyes to the protonated chitosan groups.

The results of computer simulation by the finite element method of thermoelastic stresses arising during pulsed pumping in ZnSe:Fe disk laser crystals with a different doping profile are presented. The thresholds for the occurrence of parasitic generation in a disk ZnSe:Fe laser are numerically analyzed at these doping profiles. Based on the maximum output pulse energy in a ZnSe:Fe laser and the maximum distortion of the optical density of the active element, different doping profiles were compared.

This paper reports results of a theoretical study of multilayer Ge/Si infrared photodetector parameters calculations, these calculations are of certain characteristics of detectors such as: dark current photocurrent and detectivity.

Pulsed laser ablation (PLA) in liquid is advanced method for obtaining active nanoparticles in pure solvents without the use of chemical precursors. In this work, an original approach to the synthesis of complex oxides of bismuth and silicon (BSO) is proposed. The initial colloids obtained by PLA (Nd:YAG laser, 1064 nm, 7 ns) of Bi and Si targets in water were mixed and subjected to additional irradiation with the same laser parameters. Laser treatment stimulated the formation of complex oxides. Then the colloids were dried in air and nanopowders obtained were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-Vis spectroscopy. The photocatalytic activity of the materials was examined in the Rhodamine B degradation under LED source irradiation (375 nm).

The evolution of the small-scale transverse structure of high-power femtosecond laser radiation propagating in air in the filamentation mode has been experimentally and theoretically studied. Experimental results were obtained using wideaperture (centimeter) collimated beams of femtosecond pulses of a titanium-sapphire laser. As a result, the features of propagation of spatially isolated high-intensity light channels, the diameter of which is several millimeters, were determined. They are formed because of Kerr self-focusing of intensity inhomogeneities in the initial transverse profile of the laser beam. It is shown that the formation of a filament (a localized light structure, the existence of which is associated with the plasma formation and the generation of conical emission) does not occur in each of these channels. The theoretical evaluation of this light channels characteristics was carried out. It is based on the diffraction-ray model of single filamentation of femtosecond laser pulses. Studying of the evolution transverse profile of a laser beam with a centimeter radius and subterawatt power along air path showed that the initial radius of intensity inhomogeneities, for which laser filamentation occur, is equal several (2.5-3.5) millimeters. The power in these inhomogeneities varies from 19 to 26 GW. Differences in the values of the radius and power of these inhomogeneities are the cause of different distances from the laser pulse source at which their self-focusing occurs.

An efficient model of multiple filamentation is described, which makes it possible to carry out estimated calculations and numerical experiments that simulate the effect of a turbulent atmosphere on the characteristics of femtosecond laser beams. The results of numerical experiments on the formation of a beam of optical filaments during the propagation of terawatt pulses of a titanium-sapphire laser under conditions of weak and moderate turbulence are presented. It is shown that, at moderate turbulence, the channeling mode for large (with a radius of 0.8 to 1 cm) intensity inhomogeneities in the initial profile of the laser beam is retained at distances of hundreds of meters. This occurs even when the value of the relative peak power of laser pulses exceeds the value of the critical self-focusing power no more than 1.5 times. It is found that the dependence of the relative radius of the laser beam on the propagation distance, normalized to the corresponding scale, remains constant on average.

This paper demonstrates the results of measuring the concentration of methane in atmospheric air using the developed laser Raman spectrometer. The integrated intensity method is used to determine concentrations from experimental spectra. Two methods of background correction near the methane peak are considered. It was found that the sensitivity limit of the spectrometer is less than 100 ppb. A comparison between measurements obtained using the presented setup and the CRDS gas analyzer showed sufficient agreement.

The paper presents the experimental and theoretical evaluation of sensitivity of the copper bromide vapor brightness amplifier (l=50 cm; d=3.2 cm). The research was performed in two experimental modes: Single-Pass brightness amplifier system and the Master oscillator Power Amplifier (MOPA) system. The dependencies of the gain factor (K) and the output signal power (P_OUT) on the input signal power (P_IN) are shown. The input signal power was wearied from 2 μW to 200 mW. The results show that the minimal input signal power, which can be amplified, is (0.001÷0.010) % of ASE power.

The control over beams with distributed polarization opens new ways for a wide range of applications from optical communications to laser processing of materials. This paper proposes a simple and efficient method of controlling the spatial characteristics of azimuthally polarized beams synthesized as a result of coherent combining of Gaussian beams emitted by a spatially ordered array of fiber lasers. The proposed method is based on maintaining the specified phase relations between the array subbeams by placing a phase forming element - a liquid crystal spatial light modulator - in the active feedback loop. A distinctive feature of the proposed method is the possibility of full control over beams with distributed polarization with phase control of only one component of the electric field. This leads to the significantly simpler design of the experiment. The mathematical model of beam formation and the algorithm of phase control of beams with spatially distributed polarization are discussed. The generation of beams with spatially distributed polarization, including cylindrical vector beams (CVB) and optical vortex beams (OVB), is demonstrated experimentally. The results of the experiment with an array of six fiber lasers are in a good agreement with the results of numerical simulation.

The propagation of ultrashort laser pulses in the atmosphere is accompanied by nonlinear effects. The most low-threshold of them is the effect of cubic nonlinearity along with nonlinear absorption manifesting in aerosol. This effect should lead to the transformation of the scattering phase function formed in a liquid droplet aerosol. To study this effect, numerical and experimental studies on droplets of various sizes and geometries were carried out. As expected, the cubic nonlinearity inclusion should lead to an increase in the effect of backward scattering.

Optical properties of different commercial plastics for fused deposition modeling 3D printing are defined at room temperature in the spectral range 0.2˗1.2 THz. We compare absorption coefficients and refractive index of ABS, PETG, and SBS printed 1-4 mm plates. Different types of optical elements for controlling high-power THz radiation are studied. A comparison is made of the efficiency of attenuation of linearly polarized THz radiation with homemade band-pass polarizers obtained by etching copper from a flexible polyimide substrate. Filters and polarizers created using 3D printing or by deposition of polymer matrix with magnetic particles under external field are cost-effective and can be easily changed or replaced. Comparison between plastic insets, filters based on magnetic particles, and polyimide film filters are made.

Optical properties of single axes Li₂B₄O₇ (LB4) crystal are defined at room temperature in the spectral range 0.03˗0.5 THz. Dispersion of the refractive index components are approximated in the form of Sellmeier equations. Dispersion properties were used to determine phase-matching conditions for THz wave generation by collinear difference frequency generation processes. To the damage threshold under the pump by train of hundreds of 60 fs pulses of Ti:sapphire laser operating at 950 nm is found to be 250 TW/cm², as well as the coherence length and efficiency of all possible types of three wave interactions are defined.

We report on the fabrication of liquid automated filter capable of controlling the intensity of terahertz radiation in the range of 0.4-1.4 THz. The filter is a cell with a magnetic fluid (5% dispersion of 5BDSR particles in 80W-90 synthetic oil) placed on the path of THz radiation between a pair of crossed Helmholtz coils. The prototype created allows achieving an extremely high attenuation coefficient, up to 35 dB. Automatic start-up and stirring system make filter operation repeatable, even with multiple on/off filter state changes. All this allows us to speak about the operability of the presented technology and the possibility of further development of the prototype, the use of similar filters in any THz photonics systems, in which it is required to control the intensity of polarized radiation.

Using optical spectroscopy in the spectral range from 200 to 300 nm, the absorption edge and transmission spectra of 7 samples of synthetic diamond of IIa type in the temperature range from 12 K to 470 K was studied. Using numerical methods, the temperature dependences of optical absorption into the free exciton state were obtained for negative and positive phonon branches.

Information about angular distribution of emission from the filamentation region is required to select an effective scheme for remote sensing of the aerosol atmosphere using the femtosecond laser-induced breakdown spectroscopy method. The article presents estimates of emission from the breakdown region of water aerosol by femtosecond pulses. This estimates based on the results of the emission measurements in the range of angles from 0° to 180°. For directions at the angles 60°, 90°, and 120° an estimate of the dependence of the emission intensity with a length of the filamentation region is presented.

Under the influence of atmospheric turbulence and as a result of natural vibrations of the adaptive optics system, the radiation images in the focal plane fluctuate in time relative to the laser radiation propagation axis, leading to a change in the wave front tilt angles. When accurate positioning of the focal spot is required, the elimination of angular errors becomes an important point in astronomical observations. Image stabilization on the photo detector matrix of the optical system is performed by the tilt corrector, which is one of the key elements of the software and hardware complex for emulating the tilt of the wave front.